diff --git a/bash_completion b/bash_completion
index 7cb3d32c855..b8216ae18aa 100644
--- a/bash_completion
+++ b/bash_completion
@@ -633,6 +633,46 @@ _comp_compgen_set()
     eval -- "$_var${_append:++}=(\"\$@\")"
 }
 
+# Simply split the text and generate completions.  This function should be used
+# instead of `_comp_compgen -- -W "$(command)"`, which is vulnerable because
+# option -W evaluates the shell expansions included in the option argument.
+# Options:
+#   -F sep  Specify the separators. The default is $' \t\n'
+#   -l      The same as -F $'\n'
+#   -X arg  The same as the compgen option -X.
+#   -S arg  The same as the compgen option -S.
+#   -P arg  The same as the compgen option -P.
+#   -o arg  The same as the compgen option -o.
+# @param $1 String to split
+# @since 2.12
+_comp_compgen_split()
+{
+    local _ifs=$' \t\n'
+    local -a _compgen_options=()
+
+    local OPTIND=1 OPTARG="" OPTERR=0 _opt
+    while getopts ':lF:X:S:P:o:' _opt "$@"; do
+        case $_opt in
+            l) _ifs=$'\n' ;;
+            F) _ifs=$OPTARG ;;
+            [XSPo]) _compgen_options+=("-$_opt" "$OPTARG") ;;
+            *)
+                printf 'bash_completion: usage: %s [-l|-F sep] [--] str\n' "$FUNCNAME" >&2
+                return 2
+                ;;
+        esac
+    done
+    shift "$((OPTIND - 1))"
+    if (($# != 1)); then
+        printf 'bash_completion: %s: unexpected number of arguments.\n' "$FUNCNAME" >&2
+        printf 'usage: %s [-l|-F sep] [--] str' "$FUNCNAME" >&2
+        return 2
+    fi
+
+    local _split_input=$1 IFS=$' \t\n'
+    _comp_compgen -F "$_ifs" -- ${_compgen_options[@]+"${_compgen_options[@]}"} -W '$_split_input'
+}
+
 # Check if the argument looks like a path.
 # @param $1 thing to check
 # @return True (0) if it does, False (> 0) otherwise
@@ -1143,7 +1183,7 @@ _comp_variable_assignments()
             _terms
             ;;
         LANG | LC_*)
-            _comp_compgen -- -W '$(locale -a 2>/dev/null)'
+            _comp_compgen_split -- "$(locale -a 2>/dev/null)"
             ;;
         LANGUAGE)
             _comp_delimited : -W '$(locale -a 2>/dev/null)'
@@ -1484,23 +1524,23 @@ _configured_interfaces()
         # Debian system
         _comp_expand_glob files '/etc/network/interfaces /etc/network/interfaces.d/*'
         ((${#files[@]})) || return 0
-        _comp_compgen -- -W "$(command sed -ne 's|^iface \([^ ]\{1,\}\).*$|\1|p' \
-            "${files[@]}" 2>/dev/null)"
+        _comp_compgen_split -- "$(command sed -ne \
+            's|^iface \([^ ]\{1,\}\).*$|\1|p' "${files[@]}" 2>/dev/null)"
     elif [[ -f /etc/SuSE-release ]]; then
         # SuSE system
         _comp_expand_glob files '/etc/sysconfig/network/ifcfg-*'
         ((${#files[@]})) || return 0
-        _comp_compgen -- -W "$(printf '%s\n' "${files[@]}" |
+        _comp_compgen_split -- "$(printf '%s\n' "${files[@]}" |
             command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')"
     elif [[ -f /etc/pld-release ]]; then
         # PLD Linux
-        _comp_compgen -- -W "$(command ls -B /etc/sysconfig/interfaces |
+        _comp_compgen_split -- "$(command ls -B /etc/sysconfig/interfaces |
             command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')"
     else
         # Assume Red Hat
         _comp_expand_glob files '/etc/sysconfig/network-scripts/ifcfg-*'
         ((${#files[@]})) || return 0
-        _comp_compgen -- -W "$(printf '%s\n' "${files[@]}" |
+        _comp_compgen_split -- "$(printf '%s\n' "${files[@]}" |
             command sed -ne 's|.*ifcfg-\([^*].*\)$|\1|p')"
     fi
 }
@@ -1536,7 +1576,7 @@ _ip_addresses()
 # TODO:API: rename per conventions
 _kernel_versions()
 {
-    _comp_compgen -- -W '$(command ls /lib/modules)'
+    _comp_compgen_split -- "$(command ls /lib/modules)"
 }
 
 # This function completes on all available network interfaces
@@ -1654,26 +1694,26 @@ if [[ $OSTYPE == *@(solaris|aix)* ]]; then
     # This function completes on process IDs.
     _pids()
     {
-        _comp_compgen -- -W '$(command ps -efo pid | command sed 1d)'
+        _comp_compgen_split -- "$(command ps -efo pid | command sed 1d)"
     }
 
     _pgids()
     {
-        _comp_compgen -- -W '$(command ps -efo pgid | command sed 1d)'
+        _comp_compgen_split -- "$(command ps -efo pgid | command sed 1d)"
     }
     _pnames()
     {
-        _comp_compgen -- -X '<defunct>' -W '$(command ps -efo comm | \
-            command sed -e 1d -e "s:.*/::" -e "s/^-//" | sort -u)'
+        _comp_compgen_split -X '<defunct>' -- "$(command ps -efo comm |
+            command sed -e 1d -e 's:.*/::' -e 's/^-//' | sort -u)"
     }
 else
     _pids()
     {
-        _comp_compgen -- -W '$(command ps ax -o pid=)'
+        _comp_compgen_split -- "$(command ps ax -o pid=)"
     }
     _pgids()
     {
-        _comp_compgen -- -W '$(command ps ax -o pgid=)'
+        _comp_compgen_split -- "$(command ps ax -o pgid=)"
     }
     # @param $1 if -s, don't try to avoid truncated command names
     _pnames()
@@ -1732,12 +1772,12 @@ fi
 _uids()
 {
     if type getent &>/dev/null; then
-        _comp_compgen -- -W '$(getent passwd | cut -d: -f3)'
+        _comp_compgen_split -- "$(getent passwd | cut -d: -f3)"
     elif type perl &>/dev/null; then
-        _comp_compgen -- -W '$(perl -e '"'"'while (($uid) = (getpwent)[2]) { print $uid . "\n" }'"'"')'
+        _comp_compgen_split -- "$(perl -e 'while (($uid) = (getpwent)[2]) { print $uid . "\n" }')"
     else
         # make do with /etc/passwd
-        _comp_compgen -- -W '$(cut -d: -f3 /etc/passwd)'
+        _comp_compgen_split -- "$(cut -d: -f3 /etc/passwd)"
     fi
 }
 
@@ -1747,12 +1787,12 @@ _uids()
 _gids()
 {
     if type getent &>/dev/null; then
-        _comp_compgen -- -W '$(getent group | cut -d: -f3)'
+        _comp_compgen_split -- "$(getent group | cut -d: -f3)"
     elif type perl &>/dev/null; then
-        _comp_compgen -- -W '$(perl -e '"'"'while (($gid) = (getgrent)[2]) { print $gid . "\n" }'"'"')'
+        _comp_compgen_split -- "$(perl -e 'while (($gid) = (getgrent)[2]) { print $gid . "\n" }')"
     else
         # make do with /etc/group
-        _comp_compgen -- -W '$(cut -d: -f3 /etc/group)'
+        _comp_compgen_split -- "$(cut -d: -f3 /etc/group)"
     fi
 }
 
@@ -1822,9 +1862,9 @@ _service()
     else
         local sysvdirs
         _comp_sysvdirs
-        _comp_compgen -l -- -W '$(command sed -e "y/|/ /" \
-            -ne "s/^.*\(U\|msg_u\)sage.*{\(.*\)}.*$/\2/p" \
-            ${sysvdirs[0]}/${prev##*/} 2>/dev/null) start stop'
+        _comp_compgen_split -l -- "$(command sed -e 'y/|/ /' \
+            -ne 's/^.*\(U\|msg_u\)sage.*{\(.*\)}.*$/\2/p' \
+            "${sysvdirs[0]}/${prev##*/}" 2>/dev/null) start stop"
     fi
 } &&
     complete -F _service service
@@ -1849,7 +1889,7 @@ _modules()
 {
     local modpath
     modpath=/lib/modules/$1
-    _comp_compgen -- -W "$(command ls -RL "$modpath" 2>/dev/null |
+    _comp_compgen_split -- "$(command ls -RL "$modpath" 2>/dev/null |
         command sed -ne 's/^\(.*\)\.k\{0,1\}o\(\.[gx]z\)\{0,1\}$/\1/p' \
             -e 's/^\(.*\)\.ko\.zst$/\1/p')"
 }
@@ -1859,7 +1899,7 @@ _modules()
 # TODO:API: rename per conventions (+ include "kernel" in the name)
 _installed_modules()
 {
-    _comp_compgen -c "$1" -- -W "$(PATH="$PATH:/sbin" lsmod |
+    _comp_compgen -c "$1" split -- "$(PATH="$PATH:/sbin" lsmod |
         awk '{if (NR != 1) print $1}')"
 }
 
@@ -1921,8 +1961,8 @@ _allowed_users()
     if _complete_as_root; then
         _comp_compgen -c "${1:-$cur}" -- -u
     else
-        _comp_compgen -c "${1:-$cur}" -- -W \
-            "$(id -un 2>/dev/null || whoami 2>/dev/null)"
+        _comp_compgen -c "${1:-$cur}" split -- "$(id -un 2>/dev/null ||
+            whoami 2>/dev/null)"
     fi
 }
 
@@ -1932,17 +1972,16 @@ _allowed_groups()
     if _complete_as_root; then
         _comp_compgen -c "$1" -- -g
     else
-        _comp_compgen -c "$1" -- -W \
-            "$(id -Gn 2>/dev/null || groups 2>/dev/null)"
+        _comp_compgen -c "$1" split -- "$(id -Gn 2>/dev/null ||
+            groups 2>/dev/null)"
     fi
 }
 
 # @since 2.12
 _comp_selinux_users()
 {
-    _comp_compgen -a -- -W '$(
-        semanage user -nl 2>/dev/null | awk "{ print \$1 }"
-    )'
+    _comp_compgen -a split -- "$(semanage user -nl 2>/dev/null |
+        awk '{ print $1 }')"
 }
 
 # This function completes on valid shells
@@ -2067,7 +2106,8 @@ _count_args()
 # TODO:API: rename per conventions
 _pci_ids()
 {
-    _comp_compgen -a -- -W "$(PATH="$PATH:/sbin" lspci -n | awk '{print $3}')"
+    _comp_compgen -a split -- "$(PATH="$PATH:/sbin" lspci -n |
+        awk '{print $3}')"
 }
 
 # This function completes on USB IDs
@@ -2075,7 +2115,7 @@ _pci_ids()
 # TODO:API: rename per conventions
 _usb_ids()
 {
-    _comp_compgen -a -- -W "$(PATH="$PATH:/sbin" lsusb | awk '{print $6}')"
+    _comp_compgen -a split -- "$(PATH="$PATH:/sbin" lsusb | awk '{print $6}')"
 }
 
 # CD device names
@@ -2096,7 +2136,7 @@ _dvd_devices()
 # TODO:API: rename per conventions
 _terms()
 {
-    _comp_compgen -a -- -W "$({
+    _comp_compgen -a split -- "$({
         command sed -ne 's/^\([^[:space:]#|]\{2,\}\)|.*/\1/p' /etc/termcap
         {
             toe -a || toe
@@ -2654,7 +2694,7 @@ _comp_longopt()
     [[ $was_split ]] && return
 
     if [[ $cur == -* ]]; then
-        _comp_compgen -- -W "$(LC_ALL=C $1 --help 2>&1 |
+        _comp_compgen_split -- "$(LC_ALL=C $1 --help 2>&1 |
             while read -r line; do
                 [[ $line =~ --[A-Za-z0-9]+([-_][A-Za-z0-9]+)*=? ]] &&
                     printf '%s\n' "${BASH_REMATCH[0]}"
diff --git a/completions/2to3 b/completions/2to3
index 7b5d04908ab..98ec9f40529 100644
--- a/completions/2to3
+++ b/completions/2to3
@@ -10,8 +10,9 @@ _comp_cmd_2to3()
             return
             ;;
         -f | --fix | -x | --nofix)
-            COMPREPLY=($(compgen -W \
-                "$("$1" --list-fixes 2>/dev/null | command sed -e 1d)" -- "$cur"))
+            _comp_compgen_split -- "$(
+                "$1" --list-fixes 2>/dev/null | command sed -e 1d
+            )"
             return
             ;;
         -j | --processes)
diff --git a/completions/7z b/completions/7z
index 600d8a2fdb5..368641085cb 100644
--- a/completions/7z
+++ b/completions/7z
@@ -101,10 +101,10 @@ _comp_cmd_7z()
             _comp_compgen -a filedir '@(7z?(.001)|arj|bz2|cab|cb7|chm|cpio|deb|dmg|flv|gem|img|iso|lz[ah]|lzma?(86)|msi|pmd|[rx]ar|rpm|sw[fm]|?(g)tar|taz|?(t)[bglx]z|tb?(z)2|vhd|wim|Z)'
     else
         if [[ ${words[1]} == d ]]; then
-            local IFS=$'\n'
-            COMPREPLY=($(compgen -W "$("$1" l "${words[2]}" \
-                -slt 2>/dev/null | command sed -n '/^Path =/s/^Path = \(.*\)$/\1/p' \
-                2>/dev/null | tail -n+2)" -- "$cur"))
+            _comp_compgen_split -l -- "$(
+                "$1" l "${words[2]}" -slt 2>/dev/null | command sed -n \
+                    '/^Path =/s/^Path = \(.*\)$/\1/p' 2>/dev/null | tail -n+2
+            )"
             compopt -o filenames
         else
             _comp_compgen_filedir
diff --git a/completions/_look b/completions/_look
index 6141e7a9986..20613ff6d6d 100644
--- a/completions/_look
+++ b/completions/_look
@@ -9,7 +9,7 @@ _comp_cmd_look()
     _comp_initialize -- "$@" || return
 
     if ((cword == 1)); then
-        COMPREPLY=($(compgen -W '$(look "$cur" 2>/dev/null)' -- "$cur"))
+        _comp_compgen_split -- "$(look "$cur" 2>/dev/null)"
     fi
 } &&
     complete -F _comp_cmd_look -o default look
diff --git a/completions/_mock b/completions/_mock
index e917665500b..772a7771438 100644
--- a/completions/_mock
+++ b/completions/_mock
@@ -27,7 +27,7 @@ _comp_cmd_mock()
             return
             ;;
         -r | --root)
-            COMPREPLY=($(compgen -W "$(command ls "$cfgdir")" -- "$cur"))
+            _comp_compgen_split -- "$(command ls "$cfgdir")"
             COMPREPLY=(${COMPREPLY[@]/%.cfg/})
             return
             ;;
@@ -44,9 +44,8 @@ _comp_cmd_mock()
             # (e.g. ix86 chroot builds in x86_64 mock host)
             # This would actually depend on what the target root
             # can be used to build for...
-            COMPREPLY=($(compgen -W "$(command rpm --showrc |
-                command sed -ne 's/^\s*compatible\s\s*archs\s*:\s*\(.*\)/\1/i p')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$(command rpm --showrc | command sed -ne \
+                's/^\s*compatible\s\s*archs\s*:\s*\(.*\)/\1/i p')"
             return
             ;;
         --enable-plugin | --disable-plugin)
diff --git a/completions/_mount b/completions/_mount
index 4306b66a57e..7eef693e121 100644
--- a/completions/_mount
+++ b/completions/_mount
@@ -33,8 +33,9 @@ _comp_cmd_mount()
     if [[ $cur == *:* ]]; then
         for sm in "$(type -P showmount)" {,/usr}/{,s}bin/showmount; do
             [[ -x $sm ]] || continue
-            COMPREPLY=($(compgen -W "$("$sm" -e ${cur%%:*} |
-                awk 'NR>1 {print $1}')" -- "${cur#*:}"))
+            _comp_compgen -c "${cur#*:}" split -- "$(
+                "$sm" -e ${cur%%:*} | awk 'NR>1 {print $1}'
+            )"
             return
         done
     fi
@@ -43,21 +44,27 @@ _comp_cmd_mount()
         host=${cur#//}
         host=${host%%/*}
         if [[ $host ]]; then
-            COMPREPLY=($(compgen -P "//$host" -W \
-                "$(smbclient -d 0 -NL "$host" 2>/dev/null |
+            _comp_compgen -c "${cur#//"$host"}" split -P "//$host" -- "$(
+                smbclient -d 0 -NL "$host" 2>/dev/null |
                     command sed -ne '/^[[:blank:]]*Sharename/,/^$/p' |
-                    command sed -ne '3,$s|^[^A-Za-z]*\([^[:blank:]]*\).*$|/\1|p')" \
-                -- "${cur#//"$host"}"))
+                    command sed -ne '3,$s|^[^A-Za-z]*\([^[:blank:]]*\).*$|/\1|p'
+            )"
         fi
     elif [[ -r /etc/vfstab ]]; then
         # Solaris
-        COMPREPLY=($(compgen -W "$(awk '! /^[ \t]*#/ {if ($3 ~ /\//) print $3}' /etc/vfstab)" -- "$cur"))
+        _comp_compgen_split -- "$(
+            awk '! /^[ \t]*#/ {if ($3 ~ /\//) print $3}' /etc/vfstab
+        )"
     elif [[ ! -e /etc/fstab ]]; then
         # probably Cygwin
-        COMPREPLY=($(compgen -W "$("$1" | awk '! /^[ \t]*#/ {if ($3 ~ /\//) print $3}')" -- "$cur"))
+        _comp_compgen_split -- "$(
+            "$1" | awk '! /^[ \t]*#/ {if ($3 ~ /\//) print $3}'
+        )"
     else
         # probably BSD
-        COMPREPLY=($(compgen -W "$(awk '! /^[ \t]*#/ {if ($2 ~ /\//) print $2}' /etc/fstab)" -- "$cur"))
+        _comp_compgen_split -- "$(
+            awk '! /^[ \t]*#/ {if ($2 ~ /\//) print $2}' /etc/fstab
+        )"
     fi
 } &&
     complete -F _comp_cmd_mount -o default -o dirnames mount
diff --git a/completions/_mount.linux b/completions/_mount.linux
index 89c6ec3ca64..47dc30fd28f 100644
--- a/completions/_mount.linux
+++ b/completions/_mount.linux
@@ -223,8 +223,9 @@ _comp_cmd_mount()
     if [[ $cur == *:* ]]; then
         for sm in "$(type -P showmount)" {,/usr}/{,s}bin/showmount; do
             [[ -x $sm ]] || continue
-            COMPREPLY=($(compgen -W "$("$sm" -e ${cur%%:*} |
-                awk 'NR>1 {print $1}')" -- "${cur#*:}"))
+            _comp_compgen -c "${cur#*:}" split -- "$(
+                "$sm" -e ${cur%%:*} | awk 'NR>1 {print $1}'
+            )"
             return
         done
     fi
@@ -233,11 +234,11 @@ _comp_cmd_mount()
         host=${cur#//}
         host=${host%%/*}
         if [[ $host ]]; then
-            COMPREPLY=($(compgen -P "//$host" -W \
-                "$(smbclient -d 0 -NL "$host" 2>/dev/null |
+            _comp_compgen -c "${cur#//"$host"}" split -P "//$host" -- "$(
+                smbclient -d 0 -NL "$host" 2>/dev/null |
                     command sed -ne '/^[[:blank:]]*Sharename/,/^$/p' |
-                    command sed -ne '3,$s|^[^A-Za-z]*\([^[:blank:]]*\).*$|/\1|p')" \
-                -- "${cur#//"$host"}"))
+                    command sed -ne '3,$s|^[^A-Za-z]*\([^[:blank:]]*\).*$|/\1|p'
+            )"
         fi
     fi
 
diff --git a/completions/_nmcli b/completions/_nmcli
index 05518e084b9..5e3525e9f19 100644
--- a/completions/_nmcli
+++ b/completions/_nmcli
@@ -3,35 +3,28 @@
 # Use of this file is deprecated.  Upstream completion is available in
 # NetworkManager >= 0.9.8.0, use that instead.
 
-_comp_cmd_nmcli__list()
-{
-    _comp_compgen -- -W '$1'
-}
-
 _comp_cmd_nmcli__con_id()
 {
-    local IFS=$'\n'
-    COMPREPLY=($(compgen -W "$(nmcli con list 2>/dev/null |
-        tail -n +2 | awk -F ' {2,}' '{print $1 }')" -- "$cur"))
+    _comp_compgen_split -l -- "$(nmcli con list 2>/dev/null |
+        tail -n +2 | awk -F ' {2,}' '{print $1 }')"
 }
 
 _comp_cmd_nmcli__con_uuid()
 {
-    COMPREPLY=($(compgen -W "$(nmcli con list 2>/dev/null |
-        tail -n +2 | awk -F ' {2,}' '{print $2}')" -- "$cur"))
+    _comp_compgen_split -- "$(nmcli con list 2>/dev/null |
+        tail -n +2 | awk -F ' {2,}' '{print $2}')"
 }
 
 _comp_cmd_nmcli__ap_ssid()
 {
-    local IFS=$'\n'
-    COMPREPLY=($(compgen -W "$(nmcli dev wifi list 2>/dev/null |
-        tail -n +2 | awk -F ' {2,}' '{print $1}')" -- "$cur"))
+    _comp_compgen_split -l -- "$(nmcli dev wifi list 2>/dev/null |
+        tail -n +2 | awk -F ' {2,}' '{print $1}')"
 }
 
 _comp_cmd_nmcli__ap_bssid()
 {
-    COMPREPLY=($(compgen -W "$(nmcli dev wifi list 2>/dev/null |
-        tail -n +2 | awk -F ' {2,}' '{print $2}')" -- "$cur"))
+    _comp_compgen_split -- "$(nmcli dev wifi list 2>/dev/null |
+        tail -n +2 | awk -F ' {2,}' '{print $2}')"
 }
 
 _comp_cmd_nmcli()
@@ -49,7 +42,7 @@ _comp_cmd_nmcli()
             return
             ;;
         -e | --escape)
-            _comp_cmd_nmcli__list "yes no"
+            _comp_compgen -- -W "yes no"
             return
             ;;
         id)
@@ -69,7 +62,7 @@ _comp_cmd_nmcli()
             return
             ;;
         wep-key-type)
-            _comp_cmd_nmcli__list "key phrase"
+            _comp_compgen -- -W "key phrase"
             return
             ;;
     esac
@@ -89,23 +82,23 @@ _comp_cmd_nmcli()
             nm)
                 case $command in
                     enable)
-                        _comp_cmd_nmcli__list "true false"
+                        _comp_compgen -- -W "true false"
                         return
                         ;;
                     sleep)
-                        _comp_cmd_nmcli__list "true false"
+                        _comp_compgen -- -W "true false"
                         return
                         ;;
                     wifi)
-                        _comp_cmd_nmcli__list "on off"
+                        _comp_compgen -- -W "on off"
                         return
                         ;;
                     wwan)
-                        _comp_cmd_nmcli__list "on off"
+                        _comp_compgen -- -W "on off"
                         return
                         ;;
                     wimax)
-                        _comp_cmd_nmcli__list "on off"
+                        _comp_compgen -- -W "on off"
                         return
                         ;;
                 esac
diff --git a/completions/_rfkill b/completions/_rfkill
index aad44004a68..8be15608829 100644
--- a/completions/_rfkill
+++ b/completions/_rfkill
@@ -17,9 +17,9 @@ _comp_cmd_rfkill()
                 ;;
             2)
                 if [[ $prev == block || $prev == unblock ]]; then
-                    COMPREPLY=($(compgen -W "$("$1" list | awk -F: \
-                        '/^[0-9]/ {print $1}') all wifi bluetooth uwb wimax \
-                        wwan gps" -- "$cur"))
+                    _comp_compgen_split -- "$("$1" list |
+                        awk -F: '/^[0-9]/ {print $1}') all wifi bluetooth uwb
+                        wimax wwan gps"
                 fi
                 ;;
         esac
diff --git a/completions/_udevadm b/completions/_udevadm
index f0d4ab72b60..e62e1554247 100644
--- a/completions/_udevadm
+++ b/completions/_udevadm
@@ -58,8 +58,8 @@ _comp_cmd_udevadm()
                 _comp_compgen -- -W '--help --version --debug'
                 ;;
             *)
-                COMPREPLY=($(compgen -W "$("$1" --help 2>/dev/null |
-                    awk '/^[ \t]/ { print $1 }')" -- "$cur"))
+                _comp_compgen_split -- "$("$1" --help 2>/dev/null |
+                    awk '/^[ \t]/ { print $1 }')"
                 ;;
         esac
         return
diff --git a/completions/_umount b/completions/_umount
index c6d959a9bc2..5a453a8bac1 100644
--- a/completions/_umount
+++ b/completions/_umount
@@ -16,8 +16,7 @@ _comp_cmd_umount()
     local cur prev words cword comp_args
     _comp_initialize -- "$@" || return
 
-    local IFS=$'\n'
-    COMPREPLY=($(compgen -W '$(mount | cut -d" " -f 3)' -- "$cur"))
+    _comp_compgen_split -l -- "$(mount | cut -d" " -f 3)"
 } &&
     complete -F _comp_cmd_umount -o dirnames umount
 
diff --git a/completions/_umount.linux b/completions/_umount.linux
index bb259752848..294d7608481 100644
--- a/completions/_umount.linux
+++ b/completions/_umount.linux
@@ -130,8 +130,7 @@ _comp_cmd_umount()
         # unmounting usb devices with pretty names.
         _comp_cmd_umount__linux_fstab </proc/mounts
     else
-        local IFS=$'\n'
-        COMPREPLY=($(compgen -W '$(mount | cut -d" " -f 3)' -- "$cur"))
+        _comp_compgen_split -l -- "$(mount | cut -d" " -f 3)"
     fi
 } &&
     complete -F _comp_cmd_umount -o dirnames umount
diff --git a/completions/_xm b/completions/_xm
index c96f3405b6b..84f29894029 100644
--- a/completions/_xm
+++ b/completions/_xm
@@ -6,8 +6,8 @@
 
 _comp_cmd_xm__domain_names()
 {
-    COMPREPLY=($(compgen -W "$(xm list 2>/dev/null |
-        awk '!/Name|Domain-0/ { print $1 }')" -- "$cur"))
+    _comp_compgen_split -- "$(xm list 2>/dev/null |
+        awk '!/Name|Domain-0/ { print $1 }')"
 }
 
 _comp_cmd_xm()
@@ -146,9 +146,8 @@ _comp_cmd_xm()
                             _comp_cmd_xm__domain_names
                             ;;
                         3)
-                            COMPREPLY=($(compgen -W "$(xm block-list "$prev" \
-                                2>/dev/null | awk '!/Vdev/ { print $1 }')" \
-                                -- "$cur"))
+                            _comp_compgen_split -- "$(xm block-list "$prev" \
+                                2>/dev/null | awk '!/Vdev/ { print $1 }')"
                             ;;
                     esac
                     ;;
@@ -171,9 +170,8 @@ _comp_cmd_xm()
                             _comp_cmd_xm__domain_names
                             ;;
                         3)
-                            COMPREPLY=($(compgen -W "$(xm network-list "$prev" \
-                                2>/dev/null | awk '!/Idx/ { print $1 }')" \
-                                -- "$cur"))
+                            _comp_compgen_split -- "$(xm network-list "$prev" \
+                                2>/dev/null | awk '!/Idx/ { print $1 }')"
                             ;;
                     esac
                     ;;
@@ -187,9 +185,9 @@ _comp_cmd_xm()
                     ;;
                 create)
                     _comp_compgen_filedir
-                    COMPREPLY+=(
-                        $(compgen -W '$(command ls /etc/xen 2>/dev/null)' \
-                            -- "$cur"))
+                    _comp_compgen -a split -- "$(
+                        command ls /etc/xen 2>/dev/null
+                    )"
                     ;;
                 new)
                     case $prev in
diff --git a/completions/_yum b/completions/_yum
index 2100e682678..805764920ae 100644
--- a/completions/_yum
+++ b/completions/_yum
@@ -105,17 +105,16 @@ _comp_cmd_yum()
             _comp_compgen_filedir -d
             ;;
         --enablerepo)
-            COMPREPLY=($(compgen -W '$(_yum_repolist disabled)' -- "$cur"))
+            _comp_compgen_split -- "$(_yum_repolist disabled)"
             ;;
         --disablerepo)
-            COMPREPLY=($(compgen -W '$(_yum_repolist enabled)' -- "$cur"))
+            _comp_compgen_split -- "$(_yum_repolist enabled)"
             ;;
         --disableexcludes)
-            COMPREPLY=($(compgen -W '$(_yum_repolist all) all main' \
-                -- "$cur"))
+            _comp_compgen_split -- "$(_yum_repolist all) all main"
             ;;
         --enableplugin | --disableplugin)
-            COMPREPLY=($(compgen -W '$(_yum_plugins)' -- "$cur"))
+            _comp_compgen_split -- "$(_yum_plugins)"
             ;;
         --color)
             _comp_compgen -- -W 'always auto never'
diff --git a/completions/abook b/completions/abook
index e5128d3b867..37367f93389 100644
--- a/completions/abook
+++ b/completions/abook
@@ -22,14 +22,12 @@ _comp_cmd_abook()
 
     case $prev in
         --informat)
-            COMPREPLY=($(compgen -W "$("$1" --formats |
-                command sed -n -e 's/^'$'\t''\([a-z]*\).*/\1/p' -e '/^$/q')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --formats |
+                command sed -n -e 's/^'$'\t''\([a-z]*\).*/\1/p' -e '/^$/q')"
             ;;
         --outformat)
-            COMPREPLY=($(compgen -W "$("$1" --formats |
-                command sed -n -e '/^$/,$s/^'$'\t''\([a-z]*\).*/\1/p')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --formats |
+                command sed -n -e '/^$/,$s/^'$'\t''\([a-z]*\).*/\1/p')"
             ;;
         --infile)
             _comp_compgen -- -W stdin
diff --git a/completions/appdata-validate b/completions/appdata-validate
index 66ec7a75d12..1b6149e4376 100644
--- a/completions/appdata-validate
+++ b/completions/appdata-validate
@@ -10,9 +10,8 @@ _comp_cmd_appdata_validate()
             return
             ;;
         --output-format)
-            COMPREPLY=($(compgen -W "$("$1" --help |
-                command sed -ne 's/--output-format.*\[\(.*\)\]/\1/' -e 's/|/ /gp')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --help | command sed -ne \
+                's/--output-format.*\[\(.*\)\]/\1/' -e 's/|/ /gp')"
             return
             ;;
     esac
diff --git a/completions/apt-cache b/completions/apt-cache
index 7fc8d9442ac..b83443b885b 100644
--- a/completions/apt-cache
+++ b/completions/apt-cache
@@ -25,8 +25,10 @@ _comp_xfunc_apt_cache_sources()
 # TODO:API: rework to use vars rather than outputting
 _comp_cmd_apt_cache__sources()
 {
-    compgen -W "$("$1" dumpavail |
-        awk '$1 == "Source:" { print $2 }' | sort -u)" -- "$2"
+    local ret
+    _comp_compgen -c "$2" -v ret split -- "$("$1" dumpavail |
+        awk '$1 == "Source:" { print $2 }' | sort -u)" &&
+        printf '%s\n' "${ret[@]}"
 }
 
 # List APT source packages
@@ -34,7 +36,10 @@ _comp_cmd_apt_cache__sources()
 # @since 2.12
 _comp_xfunc_apt_cache_src_packages()
 {
-    compgen -W '$(_comp_cmd_apt_cache__sources apt-cache "$cur")' -- "$cur"
+    local ret
+    _comp_compgen -v ret split -- \
+        "$(_comp_cmd_apt_cache__sources apt-cache "$cur")" &&
+        printf '%s\n' "${ret[@]}"
 }
 
 _comp_deprecate_func 2.12 _apt_cache_packages _comp_xfunc_apt_cache_packages
diff --git a/completions/apt-get b/completions/apt-get
index e1606a2f5fb..86ae7e76562 100644
--- a/completions/apt-get
+++ b/completions/apt-get
@@ -37,9 +37,9 @@ _comp_cmd_apt_get()
                 # Prefer `apt-cache` in the same dir as command
                 local pathcmd
                 pathcmd=$(type -P "$1") && local PATH=${pathcmd%/*}:$PATH
-                COMPREPLY=($(_comp_xfunc apt-cache packages)
-                $(compgen -W "$(apt-cache dumpavail |
-                    awk '$1 == "Source:" { print $2 }' | sort -u)" -- "$cur"))
+                COMPREPLY=($(_comp_xfunc apt-cache packages))
+                _comp_compgen -a split -- "$(apt-cache dumpavail |
+                    awk '$1 == "Source:" { print $2 }' | sort -u)"
                 ;;
             install | reinstall)
                 if _comp_looks_like_path "$cur"; then
@@ -48,13 +48,12 @@ _comp_cmd_apt_get()
                 elif [[ $cur == *=* ]]; then
                     package="${cur%%=*}"
                     cur="${cur#*=}"
-                    COMPREPLY=($(IFS=$'\n' compgen -W "$(
+                    _comp_compgen_split -l -- "$(
                         apt-cache --no-generate madison "$package" 2>/dev/null |
                             while IFS=' |' read -r _ version _; do
                                 echo "$version"
                             done
-                    )" \
-                        -- "$cur"))
+                    )"
                     _comp_ltrim_colon_completions "$cur"
                     return
                 fi
@@ -84,9 +83,8 @@ _comp_cmd_apt_get()
             # Prefer `apt-cache` in the same dir as command
             local pathcmd
             pathcmd=$(type -P "$1") && local PATH=${pathcmd%/*}:$PATH
-            COMPREPLY=($(compgen -W "$(apt-cache policy | command sed -ne \
-                's/^ *release.*[ ,]o=\(Debian\|Ubuntu\),a=\(\w*\).*/\2/p')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$(apt-cache policy | command sed -ne \
+                's/^ *release.*[ ,]o=\(Debian\|Ubuntu\),a=\(\w*\).*/\2/p')"
             return
             ;;
     esac
diff --git a/completions/apt-mark b/completions/apt-mark
index a26fa405f8f..bfa7df98ab0 100644
--- a/completions/apt-mark
+++ b/completions/apt-mark
@@ -18,9 +18,7 @@ _comp_cmd_apt_mark()
             auto | manual | unhold)
                 local -A showcmds=([auto]=manual [manual]=auto [unhold]=hold)
                 local showcmd=${showcmds[$special]}
-                COMPREPLY=($(
-                    compgen -W "$("$1" "show$showcmd" 2>/dev/null)" -- "$cur"
-                ))
+                _comp_compgen_split -- "$("$1" "show$showcmd" 2>/dev/null)"
                 return
                 ;;
             minimize-manual)
diff --git a/completions/aspell b/completions/aspell
index c05856a6f10..f95e52da86c 100644
--- a/completions/aspell
+++ b/completions/aspell
@@ -35,8 +35,8 @@ _comp_cmd_aspell()
             return
             ;;
         --mode)
-            COMPREPLY=($(compgen -W "$("$1" modes 2>/dev/null |
-                awk '{ print $1 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" modes 2>/dev/null |
+                awk '{ print $1 }')"
             return
             ;;
         --sug-mode)
@@ -52,8 +52,8 @@ _comp_cmd_aspell()
             return
             ;;
         --add-filter | --rem-filter)
-            COMPREPLY=($(compgen -W "$("$1" filters 2>/dev/null |
-                awk '{ print $1 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" filters 2>/dev/null |
+                awk '{ print $1 }')"
             return
             ;;
     esac
diff --git a/completions/avahi-browse b/completions/avahi-browse
index 08d24819c96..8e4ece76f7c 100644
--- a/completions/avahi-browse
+++ b/completions/avahi-browse
@@ -34,7 +34,7 @@ _comp_cmd_avahi_browse()
                 ;;
         esac
     done
-    COMPREPLY=($(compgen -W '$("$1" --dump-db --no-db-lookup)' -- "$cur"))
+    _comp_compgen_split -- "$("$1" --dump-db --no-db-lookup)"
 
 } &&
     complete -F _comp_cmd_avahi_browse avahi-browse avahi-browse-domains
diff --git a/completions/bind b/completions/bind
index 4a48ac90733..12d2343dd9e 100644
--- a/completions/bind
+++ b/completions/bind
@@ -19,7 +19,7 @@ _comp_cmd_bind()
             return
             ;;
         -*[qu])
-            COMPREPLY=($(compgen -W '$("$1" -l)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" -l)"
             return
             ;;
     esac
diff --git a/completions/brctl b/completions/brctl
index 554736a0a23..283e0694bd5 100644
--- a/completions/brctl
+++ b/completions/brctl
@@ -18,8 +18,8 @@ _comp_cmd_brctl()
                 show) ;;
 
                 *)
-                    COMPREPLY=($(compgen -W "$("$1" show |
-                        awk 'NR>1 {print $1}')" -- "$cur"))
+                    _comp_compgen_split -- "$("$1" show |
+                        awk 'NR>1 {print $1}')"
                     ;;
             esac
             ;;
diff --git a/completions/bts b/completions/bts
index 41197c341e5..65e85045abe 100644
--- a/completions/bts
+++ b/completions/bts
@@ -18,7 +18,8 @@ _comp_cmd_bts__cached_bugs()
 _comp_cmd_bts__src_packages_with_prefix()
 {
     local ppn=${cur:4} # partial package name, after stripping "src:"
-    _comp_compgen -ac "$ppn" -- -P "src:" -W '$(_comp_xfunc apt-cache sources "$ppn")'
+    _comp_compgen -ac "$ppn" split -P "src:" -- \
+        "$(_comp_xfunc apt-cache sources "$ppn")"
 }
 
 _comp_cmd_bts()
diff --git a/completions/cancel b/completions/cancel
index ab07318d96d..64770453a41 100644
--- a/completions/cancel
+++ b/completions/cancel
@@ -19,8 +19,7 @@ _comp_cmd_cancel()
             ;;
     esac
 
-    COMPREPLY=($(compgen -W \
-        "$(lpstat 2>/dev/null | cut -d' ' -f1)" -- "$cur"))
+    _comp_compgen_split -- "$(lpstat 2>/dev/null | cut -d' ' -f1)"
 } &&
     complete -F _comp_cmd_cancel cancel
 
diff --git a/completions/ccache b/completions/ccache
index c8cf2e002b5..3e3d8c16de6 100644
--- a/completions/ccache
+++ b/completions/ccache
@@ -22,8 +22,8 @@ _comp_cmd_ccache()
             ;;
         --set-config | -${noargopts}o)
             if [[ $cur != *=* ]]; then
-                COMPREPLY=($(compgen -S = -W "$("$1" -p 2>/dev/null |
-                    awk '$3 = "=" { print $2 }')" -- "$cur"))
+                _comp_compgen_split -S = -- "$("$1" -p 2>/dev/null |
+                    awk '$3 = "=" { print $2 }')"
                 [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
             fi
             return
diff --git a/completions/ccze b/completions/ccze
index c3b372f1e49..31602b09eca 100644
--- a/completions/ccze
+++ b/completions/ccze
@@ -29,9 +29,8 @@ _comp_cmd_ccze()
             return
             ;;
         --plugin | -${noargopts}p)
-            COMPREPLY=($(compgen -W '$("$1" --list-plugins | command \
-                sed -ne "s/^\([a-z0-9]\{1,\}\)[[:space:]]\{1,\}|.*/\1/p")' \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-plugins | command \
+                sed -ne 's/^\([a-z0-9]\{1,\}\)[[:space:]]\{1,\}|.*/\1/p')"
             return
             ;;
     esac
diff --git a/completions/cfrun b/completions/cfrun
index 64a68b60960..445bccd0f26 100644
--- a/completions/cfrun
+++ b/completions/cfrun
@@ -33,8 +33,8 @@ _comp_cmd_cfrun()
                 done
                 [[ ! -f $hostfile ]] && return
 
-                COMPREPLY=($(compgen -W "$(command grep -v \
-                    -E '(=|^$|^#)' "$hostfile")" -- "$cur"))
+                _comp_compgen_split -- "$(command grep -v -E '(=|^$|^#)' \
+                    "$hostfile")"
             fi
             ;;
         2)
diff --git a/completions/checksec b/completions/checksec
index a87459cf658..98f78664a42 100644
--- a/completions/checksec
+++ b/completions/checksec
@@ -26,18 +26,12 @@ _comp_cmd_checksec()
             return
             ;;
         --format)
-            COMPREPLY=($(compgen -W '$("$1" --help 2>/dev/null |
-                command sed \
-                     -e "s/[{,}]/ /g" \
-                    -ne "s/^[[:space:]]*--format=//p"
-                )' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --help 2>/dev/null |
+                command sed -ne 's/[{,}]/ /g;s/^[[:space:]]*--format=//p')"
             ;;
         --output)
-            COMPREPLY=($(compgen -W '$("$1" --help 2>/dev/null |
-                command sed \
-                     -e "s/[{,}]/ /g" \
-                    -ne "s/^[[:space:]]*--output=//p"
-                )' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --help 2>/dev/null |
+                command sed -ne 's/[{,}]/ /g;s/^[[:space:]]*--output=//p')"
             ;;
     esac
 
diff --git a/completions/chronyc b/completions/chronyc
index b1cc9a9881d..000a747de40 100644
--- a/completions/chronyc
+++ b/completions/chronyc
@@ -42,9 +42,8 @@ _comp_cmd_chronyc()
 
     case $args in
         0)
-            COMPREPLY=($(compgen -W "$("$1" help 2>/dev/null |
-                awk '!/(^ |: *$)/ { sub("\\|", " ", $1); print $1 }')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" help 2>/dev/null |
+                awk '!/(^ |: *$)/ { sub("\\|", " ", $1); print $1 }')"
             ;;
         1)
             _comp_cmd_chronyc__command_args "$1"
diff --git a/completions/configure b/completions/configure
index 92768d170ef..42467237905 100644
--- a/completions/configure
+++ b/completions/configure
@@ -28,10 +28,9 @@ _comp_cmd_configure()
     # if $BASH_COMPLETION_CMD_CONFIGURE_HINTS is not null, then completions of
     # the form --option=SETTING will include 'SETTING' as a contextual hint
     if [[ ${BASH_COMPLETION_CMD_CONFIGURE_HINTS-${COMP_CONFIGURE_HINTS-}} ]]; then
-        COMPREPLY=($(compgen -W "$("$1" --help 2>&1 |
+        _comp_compgen_split -- "$("$1" --help 2>&1 |
             awk '/^  --[A-Za-z]/ { print $1; \
-            if ($2 ~ /--[A-Za-z]/) print $2 }' | command sed -e 's/[[,].*//g')" \
-            -- "$cur"))
+            if ($2 ~ /--[A-Za-z]/) print $2 }' | command sed -e 's/[[,].*//g')"
         [[ ${COMPREPLY-} == *=* ]] && compopt -o nospace
     else
         _comp_compgen_help
diff --git a/completions/convert b/completions/convert
index caff5ab2979..96091178861 100644
--- a/completions/convert
+++ b/completions/convert
@@ -49,9 +49,8 @@ _comp_cmd_convert__common_options()
             return
             ;;
         -format)
-            COMPREPLY=($(compgen -W "$(convert -list format | awk \
-                '/ [r-][w-][+-] / { sub("[*]$","",$1); print tolower($1) }')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$(convert -list format | awk \
+                '/ [r-][w-][+-] / { sub("[*]$","",$1); print tolower($1) }')"
             return
             ;;
         -gravity)
diff --git a/completions/cowsay b/completions/cowsay
index 2a74a4e77e2..ea1468caf5b 100644
--- a/completions/cowsay
+++ b/completions/cowsay
@@ -7,8 +7,7 @@ _comp_cmd_cowsay()
 
     case $prev in
         -f)
-            COMPREPLY=($(compgen -W \
-                '$(cowsay -l 2>/dev/null | tail -n +2)' -- "$cur"))
+            _comp_compgen_split -- "$(cowsay -l 2>/dev/null | tail -n +2)"
             return
             ;;
     esac
diff --git a/completions/cpan2dist b/completions/cpan2dist
index 20c0f5e4eff..046b6d3faaa 100644
--- a/completions/cpan2dist
+++ b/completions/cpan2dist
@@ -8,9 +8,8 @@ _comp_cmd_cpan2dist()
     case $prev in
         --format)
             # should remove ":" from COMP_WORDBREAKS, but doesn't work (?)
-            COMPREPLY=($(compgen -W '$(perl -MCPANPLUS::Dist -e \
-                "print map { \"\$_\n\" } CPANPLUS::Dist->dist_types")' \
-                -- "$cur"))
+            _comp_compgen_split -- "$(perl -MCPANPLUS::Dist -e \
+                'print map { "$_n" } CPANPLUS::Dist->dist_types')"
             return
             ;;
         --banlist | --ignorelist | --modulelist | --logfile)
diff --git a/completions/cryptsetup b/completions/cryptsetup
index 1169e7411b0..9604b08790d 100644
--- a/completions/cryptsetup
+++ b/completions/cryptsetup
@@ -2,7 +2,7 @@
 
 _comp_cmd_cryptsetup__name()
 {
-    COMPREPLY=($(compgen -X control -W '$(command ls /dev/mapper)' -- "$cur"))
+    _comp_compgen_split -X control -- "$(command ls /dev/mapper)"
 }
 
 _comp_cmd_cryptsetup__device()
diff --git a/completions/cvs b/completions/cvs
index 5afd6491a9f..aeda845bfcf 100644
--- a/completions/cvs
+++ b/completions/cvs
@@ -70,7 +70,7 @@ _comp_cmd_cvs()
             # shellcheck disable=SC2254
             case $i in
                 --help | -${noargopts}H)
-                    COMPREPLY=($(compgen -W "$(_cvs_commands)" -- "$cur"))
+                    _comp_compgen_split -- "$(_cvs_commands)"
                     return
                     ;;
                 -${noargopts}d)
@@ -409,8 +409,8 @@ _comp_cmd_cvs()
             esac
 
             _comp_compgen_help -- --help-options
-            _comp_compgen -a -- -W '$(_cvs_commands) --help
-                --help-commands --help-options --version'
+            _comp_compgen -a split -- "$(_cvs_commands) --help
+                --help-commands --help-options --version"
             ;;
     esac
 
diff --git a/completions/cvsps b/completions/cvsps
index 7f0ffe7a9f3..b445e5c8d5e 100644
--- a/completions/cvsps
+++ b/completions/cvsps
@@ -10,23 +10,23 @@ _comp_cmd_cvsps()
             return
             ;;
         -s)
-            COMPREPLY=($(compgen -W "$("$1" 2>/dev/null |
-                awk '/^PatchSet:?[ \t]/ { print $2 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" 2>/dev/null |
+                awk '/^PatchSet:?[ \t]/ { print $2 }')"
             return
             ;;
         -a)
-            COMPREPLY=($(compgen -W "$("$1" 2>/dev/null |
-                awk '/^Author:[ \t]/ { print $2 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" 2>/dev/null |
+                awk '/^Author:[ \t]/ { print $2 }')"
             return
             ;;
         -b)
-            COMPREPLY=($(compgen -W "$("$1" 2>/dev/null |
-                awk '/^Branch:[ \t]/ { print $2 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" 2>/dev/null |
+                awk '/^Branch:[ \t]/ { print $2 }')"
             return
             ;;
         -r)
-            COMPREPLY=($(compgen -W "$("$1" 2>/dev/null |
-                awk '/^Tag:[ \t]+[^(]/ { print $2 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" 2>/dev/null |
+                awk '/^Tag:[ \t]+[^(]/ { print $2 }')"
             return
             ;;
         -p)
diff --git a/completions/dict b/completions/dict
index 424d77ad70b..edcaae94f52 100644
--- a/completions/dict
+++ b/completions/dict
@@ -42,11 +42,11 @@ _comp_cmd_dict()
     # shellcheck disable=SC2254
     case $prev in
         --database | -info | -${noargopts}[di])
-            COMPREPLY=($(compgen -W '$(_dictdata -D)' -- "$cur"))
+            _comp_compgen_split -- "$(_dictdata -D)"
             return
             ;;
         --strategy | -${noargopts}s)
-            COMPREPLY=($(compgen -W '$(_dictdata -S)' -- "$cur"))
+            _comp_compgen_split -- "$(_dictdata -S)"
             return
             ;;
     esac
@@ -57,10 +57,11 @@ _comp_cmd_dict()
         # it down with grep if $cur looks like something that's safe to embed
         # in a pattern instead.
         if [[ $cur == +([-A-Za-z0-9/.]) ]]; then
-            COMPREPLY=($(compgen -W \
-                '$(command grep "^${cur//./\\.}" "$dictfile")' -- "$cur"))
+            _comp_compgen_split -- "$(
+                command grep "^${cur//./\\.}" "$dictfile"
+            )"
         else
-            COMPREPLY=($(compgen -W '$(cat "$dictfile")' -- "$cur"))
+            _comp_compgen_split -- "$(cat "$dictfile")"
         fi
     fi
 } &&
diff --git a/completions/ebtables b/completions/ebtables
index 5e456957aab..24f3fe71fb6 100644
--- a/completions/ebtables
+++ b/completions/ebtables
@@ -16,30 +16,29 @@ _comp_cmd_ebtables()
     # shellcheck disable=SC2254
     case $prev in
         -${noargopts}[AIDPFXLZ])
-            COMPREPLY=($(compgen -W '`"$1" ${table:+-t "$table"} -L 2>/dev/null | \
-                command sed -ne "$chain"`' -- "$cur"))
+            _comp_compgen_split -- "$(
+                "$1" ${table:+-t "$table"} -L 2>/dev/null |
+                    command sed -ne "$chain"
+            )"
             ;;
         -${noargopts}t)
             _comp_compgen -- -W 'nat filter broute'
             ;;
         -${noargopts}j)
             if [[ $table == "filter" || ! $table ]]; then
-                COMPREPLY=($(compgen -W '$targets
-                $("$1" ${table:+-t "$table"} -L 2>/dev/null | \
-                  command sed -n -e "s/INPUT\|OUTPUT\|FORWARD//" \
-                                 -e "$chain")' \
-                    -- "$cur"))
+                _comp_compgen -- -W '$targets'
+                _comp_compgen -a split -- "$("$1" ${table:+-t "$table"} -L \
+                    2>/dev/null | command sed -n -e \
+                    "s/INPUT\|OUTPUT\|FORWARD//" -e "$chain")"
             elif [[ $table == "nat" ]]; then
-                COMPREPLY=($(compgen -W '$targets
-                $("$1" -t "$table" -L 2>/dev/null | \
-                  command sed -n -e "s/OUTPUT|PREROUTING|POSTROUTING//" \
-                                 -e "$chain")' \
-                    -- "$cur"))
+                _comp_compgen -- -W '$targets'
+                _comp_compgen -a split -- "$("$1" -t "$table" -L 2>/dev/null |
+                    command sed -n -e "s/OUTPUT|PREROUTING|POSTROUTING//" \
+                        -e "$chain")"
             elif [[ $table == "broute" ]]; then
-                COMPREPLY=($(compgen -W 'ACCEPT DROP
-                $("$1" -t "$table" -L 2>/dev/null | \
-                  command sed -n -e "s/BROUTING//" -e "$chain")' \
-                    -- "$cur"))
+                _comp_compgen -- -W 'ACCEPT DROP'
+                _comp_compgen -a split -- "$("$1" -t "$table" -L 2>/dev/null |
+                    command sed -n -e "s/BROUTING//" -e "$chain")"
             fi
             ;;
         *)
diff --git a/completions/fbgs b/completions/fbgs
index 0c766ce0c10..66bcbbb1077 100644
--- a/completions/fbgs
+++ b/completions/fbgs
@@ -7,14 +7,13 @@ _comp_cmd_fbgs()
 
     case "$prev" in
         -f | --font)
-            local IFS=$'\n'
-            COMPREPLY=($(compgen -W '$(fc-list 2>/dev/null)' -- "$cur"))
+            _comp_compgen_split -l -- "$(fc-list 2>/dev/null)"
             return
             ;;
         -m | --mode)
-            COMPREPLY=($(compgen -W '$(command sed \
-                -n "/^mode/{s/^mode \{1,\}\"\([^\"]\{1,\}\)\"/\1/g;p}" \
-                /etc/fb.modes 2>/dev/null)' -- "$cur"))
+            _comp_compgen_split -- "$(command sed \
+                -n '/^mode/{s/^mode \{1,\}"\([^"]\{1,\}\)"/\1/g;p}' \
+                /etc/fb.modes 2>/dev/null)"
             return
             ;;
         -d | --device)
diff --git a/completions/fbi b/completions/fbi
index d4533146fdc..275395e41f6 100644
--- a/completions/fbi
+++ b/completions/fbi
@@ -15,14 +15,13 @@ _comp_cmd_fbi()
             return
             ;;
         -f | --font)
-            local IFS=$'\n'
-            COMPREPLY=($(compgen -W '$(fc-list 2>/dev/null)' -- "$cur"))
+            _comp_compgen_split -l -- "$(fc-list 2>/dev/null)"
             return
             ;;
         -m | --mode)
-            COMPREPLY=($(compgen -W '$(command sed \
-                -n "/^mode/{s/^mode \{1,\}\"\([^\"]\{1,\}\)\"/\1/g;p}" \
-                /etc/fb.modes 2>/dev/null)' -- "$cur"))
+            _comp_compgen_split -- "$(command sed \
+                -n '/^mode/{s/^mode \{1,\}"\([^"]\{1,\}\)"/\1/g;p}' \
+                /etc/fb.modes 2>/dev/null)"
             return
             ;;
         -d | --device)
diff --git a/completions/fio b/completions/fio
index 6593be31626..18647ea2150 100644
--- a/completions/fio
+++ b/completions/fio
@@ -32,7 +32,7 @@ _comp_cmd_fio()
             return
             ;;
         --crctest)
-            COMPREPLY=($(compgen -W '$("$1" --crctest=nonexistent 2>/dev/null)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --crctest=nonexistent 2>/dev/null)"
             return
             ;;
         --cmdhelp)
@@ -141,9 +141,8 @@ _comp_cmd_fio()
 
     if [[ $cur == -* ]]; then
         _comp_compgen_help
-        local stdout=$("$1" --cmdhelp=all 2>/dev/null |
-            awk '{printf "--%s=\n", $1}')
-        _comp_compgen -a -- -W '$stdout'
+        _comp_compgen -a split -- "$("$1" --cmdhelp=all 2>/dev/null |
+            awk '{printf "--%s=\n", $1}')"
         [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
         return
     fi
diff --git a/completions/firefox b/completions/firefox
index 731347b920d..d763060e791 100644
--- a/completions/firefox
+++ b/completions/firefox
@@ -14,10 +14,10 @@ _comp_cmd_firefox()
             return
             ;;
         -P)
-            COMPREPLY=($(compgen -W "$(
+            _comp_compgen_split -- "$(
                 awk -F= '$1 == "Name" { print $2 }' \
                     ~/.mozilla/firefox/profiles.ini 2>/dev/null
-            )" -- "$cur"))
+            )"
             return
             ;;
         --profile | --screenshot)
diff --git a/completions/fusermount b/completions/fusermount
index 26c6c3ef26f..716ac2a767a 100644
--- a/completions/fusermount
+++ b/completions/fusermount
@@ -10,9 +10,8 @@ _comp_cmd_fusermount()
             return
             ;;
         -*u)
-            COMPREPLY=($(compgen -W "$(awk \
-                '{ if ($3 ~ /^fuse(\.|$)/) print $2 }' /etc/mtab \
-                2>/dev/null)" -- "$cur"))
+            _comp_compgen_split -- "$(awk \
+                '{ if ($3 ~ /^fuse(\.|$)/) print $2 }' /etc/mtab 2>/dev/null)"
             return
             ;;
     esac
diff --git a/completions/gcc b/completions/gcc
index 27d4d2613fd..038fc4274a4 100644
--- a/completions/gcc
+++ b/completions/gcc
@@ -11,9 +11,8 @@ _comp_cmd_gcc()
         if [[ $cur == -* ]]; then
             local cc=$("$1" -print-prog-name=cc1 2>/dev/null)
             [[ $cc ]] || return
-            COMPREPLY=($(compgen -W "$("$cc" --help 2>/dev/null | tr '\t' ' ' |
-                command sed -e '/^  *-/!d' -e 's/ *-\([^][ <>]*\).*/-\1/')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$cc" --help 2>/dev/null | tr '\t' ' ' |
+                command sed -e '/^  *-/!d' -e 's/ *-\([^][ <>]*\).*/-\1/')"
             [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
         else
             _comp_compgen_filedir
diff --git a/completions/gdb b/completions/gdb
index 4a797165934..7c1f9c9857c 100644
--- a/completions/gdb
+++ b/completions/gdb
@@ -29,14 +29,15 @@ _comp_cmd_gdb()
             local path_array=($(
                 command sed -e 's/:\{2,\}/:/g' -e 's/^://' -e 's/:$//' <<<"$PATH"
             ))
-            IFS=$'\n'
-            COMPREPLY=($(compgen -d -W '$(find ${path_array[@]+"${path_array[@]}"} . \
-                -mindepth 1 -maxdepth 1 -not -type d -executable \
-                -printf "%f\\n" 2>/dev/null)' -- "$cur"))
+            _comp_compgen_split -o plusdirs -- "$(
+                find ${path_array[@]+"${path_array[@]}"} . -mindepth 1 \
+                    -maxdepth 1 -not -type d -executable -printf '%f\n' \
+                    2>/dev/null
+            )"
         fi
     elif ((cword == 2)); then
-        COMPREPLY=($(compgen -W "$(command ps axo comm,pid |
-            awk '{if ($1 ~ /^'"${prev##*/}"'/) print $2}')" -- "$cur"))
+        _comp_compgen_split -- "$(command ps axo comm,pid |
+            awk '{if ($1 ~ /^'"${prev##*/}"'/) print $2}')"
         compopt -o filenames
         _comp_compgen -a -- -f -X '!?(*/)core?(.?*)' -o plusdirs
     fi
diff --git a/completions/genisoimage b/completions/genisoimage
index ba735721481..98ab3dc2d9a 100644
--- a/completions/genisoimage
+++ b/completions/genisoimage
@@ -12,8 +12,8 @@ _comp_cmd_mkisofs()
             return
             ;;
         -*-charset)
-            COMPREPLY=($(compgen -W '$(mkisofs -input-charset \
-                    help 2>&1 | tail -n +3)' -- "$cur"))
+            _comp_compgen_split -- "$(mkisofs -input-charset help 2>&1 |
+                tail -n +3)"
             return
             ;;
         -uid)
diff --git a/completions/getconf b/completions/getconf
index 4c410ac32ce..35b55a727ee 100644
--- a/completions/getconf
+++ b/completions/getconf
@@ -11,9 +11,9 @@ _comp_cmd_getconf()
             return
             ;;
         -v)
-            COMPREPLY=($(compgen -W \
-                '$("$1" -a 2>/dev/null | awk "{ print \$1 }")' -- \
-                "${cur:-POSIX_V}"))
+            _comp_compgen -c "${cur:-POSIX_V}" split -- "$(
+                "$1" -a 2>/dev/null | awk '{ print $1 }'
+            )"
             return
             ;;
     esac
@@ -23,8 +23,9 @@ _comp_cmd_getconf()
     elif [[ $cur == -* ]]; then
         _comp_compgen -- -W '-a -v'
     else
-        COMPREPLY=($(compgen -W \
-            '$("$1" -a 2>/dev/null | awk "{ print \$1 }")' -- "$cur"))
+        _comp_compgen_split -- "$(
+            "$1" -a 2>/dev/null | awk '{ print $1 }'
+        )"
     fi
 } &&
     complete -F _comp_cmd_getconf getconf
diff --git a/completions/getent b/completions/getent
index 8b34b814fea..2c32b9f8935 100644
--- a/completions/getent
+++ b/completions/getent
@@ -45,12 +45,11 @@ _comp_cmd_getent()
             return
             ;;
         protocols | networks | ahosts | ahostsv4 | ahostsv6 | rpc)
-            COMPREPLY=($(compgen -W "$("$1" "$db" |
-                awk '{ print $1 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" "$db" | awk '{ print $1 }')"
             return
             ;;
         aliases | shadow | gshadow)
-            COMPREPLY=($(compgen -W "$("$1" "$db" | cut -d: -f1)" -- "$cur"))
+            _comp_compgen_split -- "$("$1" "$db" | cut -d: -f1)"
             return
             ;;
         ethers | netgroup)
diff --git a/completions/gm b/completions/gm
index 4eba56ae840..9671f9b9a0e 100644
--- a/completions/gm
+++ b/completions/gm
@@ -2,8 +2,8 @@
 
 _comp_cmd_gm__commands()
 {
-    COMPREPLY+=($(compgen -W '$("$1" help |
-        awk "/^ +[^ ]+ +- / { print \$1 }")' -- "$cur"))
+    _comp_compgen -a split -- "$("$1" help |
+        awk '/^ +[^ ]+ +- / { print $1 }')"
 }
 
 _comp_cmd_gm()
diff --git a/completions/gnokii b/completions/gnokii
index ddd21f25f7d..21fb13c4823 100644
--- a/completions/gnokii
+++ b/completions/gnokii
@@ -24,9 +24,8 @@ _comp_cmd_gnokii()
                 [[ -f $config_file ]] && break
             done
             [[ ! -f $config_file ]] && return
-            COMPREPLY=($(compgen -W \
-                "$(command sed -n 's/^\[phone_\(.*\)\]/\1/p' "$config_file")" \
-                -- "$cur"))
+            _comp_compgen_split -- "$(command sed -n \
+                's/^\[phone_\(.*\)\]/\1/p' "$config_file")"
             return
             ;;
         --help)
diff --git a/completions/gpg b/completions/gpg
index 901334d3d38..ca0d8e07f69 100644
--- a/completions/gpg
+++ b/completions/gpg
@@ -19,33 +19,33 @@ _comp_cmd_gpg()
             --search-keys | --edit-key | --sign-key | --lsign-key | \
             --nrsign-key | --nrlsign-key | --try-secret-key | -${noargopts}k)
             # return list of public keys
-            COMPREPLY=($(compgen -W "$("$1" --list-keys 2>/dev/null |
+            _comp_compgen_split -- "$("$1" --list-keys 2>/dev/null |
                 command sed -ne \
                     's@^pub.*/\([^ ]*\).*$@\1@p' -ne \
-                    's@^.*\(<\([^>]*\)>\).*$@\2@p')" -- "$cur"))
+                    's@^.*\(<\([^>]*\)>\).*$@\2@p')"
             return
             ;;
         --list-secret-keys | --delete-secret-keys | --export-secret-keys | \
             --export-secret-subkeys | -${noargopts}K)
             # return list of secret keys
-            COMPREPLY=($(compgen -W "$("$1" --list-secret-keys 2>/dev/null |
-                command sed -ne 's@^.*<\([^>]*\)>.*$@\1@p')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-secret-keys 2>/dev/null |
+                command sed -ne 's@^.*<\([^>]*\)>.*$@\1@p')"
             return
             ;;
         --recipient | -${noargopts}r)
-            COMPREPLY=($(compgen -W "$("$1" --list-keys 2>/dev/null |
-                command sed -ne 's@^.*<\([^>]*\)>.*$@\1@p')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-keys 2>/dev/null |
+                command sed -ne 's@^.*<\([^>]*\)>.*$@\1@p')"
             if [[ -e ~/.gnupg/gpg.conf ]]; then
-                COMPREPLY+=($(compgen -W "$(command sed -ne \
+                _comp_compgen -a split -- "$(command sed -ne \
                     's@^[ \t]*group[ \t][ \t]*\([^=]*\).*$@\1@p' \
-                    ~/.gnupg/gpg.conf)" -- "$cur"))
+                    ~/.gnupg/gpg.conf)"
             fi
             return
             ;;
     esac
 
     if [[ $cur == -* ]]; then
-        COMPREPLY=($(compgen -W '$("$1" --dump-options)' -- "$cur"))
+        _comp_compgen_split -- "$("$1" --dump-options)"
     fi
 } &&
     complete -F _comp_cmd_gpg -o default gpg
diff --git a/completions/gpg2 b/completions/gpg2
index 65d70c0f100..fc54ff96714 100644
--- a/completions/gpg2
+++ b/completions/gpg2
@@ -20,26 +20,26 @@ _comp_cmd_gpg2()
             --edit-key | --delete-keys | --delete-secret-and-public-keys | \
             --locate-keys | --refresh-keys)
             # return list of public keys
-            COMPREPLY=($(compgen -W "$("$1" --list-keys 2>/dev/null |
+            _comp_compgen_split -- "$("$1" --list-keys 2>/dev/null |
                 command sed -ne \
                     's@^pub.*/\([^ ]*\).*$@\1@p' -ne \
-                    's@^.*\(<\([^>]*\)>\).*$@\2@p')" -- "$cur"))
+                    's@^.*\(<\([^>]*\)>\).*$@\2@p')"
             return
             ;;
         --recipient | -${noargopts}r)
-            COMPREPLY=($(compgen -W "$("$1" --list-keys 2>/dev/null |
-                command sed -ne 's@^.*<\([^>]*\)>.*$@\1@p')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-keys 2>/dev/null |
+                command sed -ne 's@^.*<\([^>]*\)>.*$@\1@p')"
             if [[ -e ~/.gnupg/gpg.conf ]]; then
-                COMPREPLY+=($(compgen -W "$(command sed -ne \
+                _comp_compgen -a split -- "$(command sed -ne \
                     's@^[ \t]*group[ \t][ \t]*\([^=]*\).*$@\1@p' \
-                    ~/.gnupg/gpg.conf)" -- "$cur"))
+                    ~/.gnupg/gpg.conf)"
             fi
             return
             ;;
     esac
 
     if [[ $cur == -* ]]; then
-        COMPREPLY=($(compgen -W '$("$1" --dump-options)' -- "$cur"))
+        _comp_compgen_split -- "$("$1" --dump-options)"
     fi
 } &&
     complete -F _comp_cmd_gpg2 -o default gpg2
diff --git a/completions/gphoto2 b/completions/gphoto2
index bd5fb6f6a58..48de5f99b71 100644
--- a/completions/gphoto2
+++ b/completions/gphoto2
@@ -23,21 +23,18 @@ _comp_cmd_gphoto2()
             return
             ;;
         --port)
-            COMPREPLY=($(compgen -W "$("$1" --list-ports 2>/dev/null |
-                awk 'NR>3 { print $1 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-ports 2>/dev/null |
+                awk 'NR>3 { print $1 }')"
             _comp_ltrim_colon_completions "$cur"
             return
             ;;
         --camera)
-            local IFS=$'\n'
-            COMPREPLY=($(compgen -W "$("$1" --list-cameras 2>/dev/null |
-                awk -F'"' 'NR>2 { print $2 }')" -- "$cur"))
+            _comp_compgen_split -l -- "$("$1" --list-cameras 2>/dev/null |
+                awk -F'"' 'NR>2 { print $2 }')"
             return
             ;;
         --get-config | --set-config | --set-config-index | --set-config-value)
-            COMPREPLY=($(compgen -W "$(
-                $1 --list-config 2>/dev/null
-            )" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-config 2>/dev/null)"
             return
             ;;
     esac
diff --git a/completions/hcitool b/completions/hcitool
index b87ea01c321..94b23e10fdd 100644
--- a/completions/hcitool
+++ b/completions/hcitool
@@ -3,15 +3,13 @@
 _comp_cmd_hcitool__bluetooth_addresses()
 {
     if [[ ${COMP_BLUETOOTH_SCAN-} ]]; then
-        COMPREPLY+=($(compgen -W "$(hcitool scan |
-            awk '/^\t/{print $1}')" -- "$cur"))
+        _comp_compgen -a split -- "$(hcitool scan | awk '/^\t/{print $1}')"
     fi
 }
 
 _comp_cmd_hcitool__bluetooth_devices()
 {
-    COMPREPLY+=($(compgen -W "$(hcitool dev |
-        awk '/^\t/{print $1}')" -- "$cur"))
+    _comp_compgen -a split -- "$(hcitool dev | awk '/^\t/{print $1}')"
 }
 
 _comp_cmd_hcitool__bluetooth_services()
diff --git a/completions/htop b/completions/htop
index 3ebb217495a..6a0f79760c8 100644
--- a/completions/htop
+++ b/completions/htop
@@ -9,7 +9,7 @@ _comp_cmd_htop()
     # shellcheck disable=SC2254
     case "$prev" in
         --sort-key | -${noargopts}s)
-            COMPREPLY=($(compgen -W '$("$1" -s help)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" -s help)"
             return
             ;;
         --user | -${noargopts}u)
diff --git a/completions/htpasswd b/completions/htpasswd
index 739f9d6b45d..dafd1d96396 100644
--- a/completions/htpasswd
+++ b/completions/htpasswd
@@ -27,8 +27,7 @@ _comp_cmd_htpasswd()
 
     elif ((o == cword - 1)); then
         # Username (second non-option argument)
-        COMPREPLY=($(compgen -W \
-            '$(cut -d: -f1 "${words[o]}" 2>/dev/null)' -- "$cur"))
+        _comp_compgen_split -- "$(cut -d: -f1 "${words[o]}" 2>/dev/null)"
     fi
 } &&
     complete -F _comp_cmd_htpasswd htpasswd
diff --git a/completions/iconv b/completions/iconv
index 8e392e5235e..9cfab2d5208 100644
--- a/completions/iconv
+++ b/completions/iconv
@@ -14,8 +14,8 @@ _iconv_charsets()
 
 _comp_cmd_iconv__charsets()
 {
-    COMPREPLY+=($(compgen -X ... -W '$("$1" -l | \
-        command sed -e "s@/*\$@@" -e "s/[,()]//g")' -- "$cur"))
+    _comp_compgen -a split -X ... -- "$("$1" -l |
+        command sed -e 's@/*$@@' -e 's/[,()]//g')"
 }
 
 _comp_cmd_iconv()
diff --git a/completions/ifstat b/completions/ifstat
index 93467b96360..d47759b67d6 100644
--- a/completions/ifstat
+++ b/completions/ifstat
@@ -23,8 +23,8 @@ _comp_cmd_ifstat()
                 "$1" --help 2>&1 || :
             } |
                 command grep -q -- '-d.*--scan'; then
-                COMPREPLY=($(compgen -W '$("$1" -v | command \
-                    sed -e "s/[,.]//g" -ne "s/^.*drivers://p")' -- "$cur"))
+                _comp_compgen_split -- "$("$1" -v | command sed -e 's/[,.]//g' \
+                    -ne 's/^.*drivers://p')"
             fi
             return
             ;;
@@ -49,9 +49,8 @@ _comp_cmd_ifstat()
             ;;
         --extended | -${noargopts}x)
             # iproute2: parse xstat types
-            COMPREPLY=($(compgen -W '$("$1" -x nonexistent-xstat 2>&1 |
-                awk "found { print \$1 } /supported xstats:/ { found=1 }")' \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" -x nonexistent-xstat 2>&1 |
+                awk 'found { print $1 } /supported xstats:/ { found=1 }')"
             return
             ;;
     esac
diff --git a/completions/inotifywait b/completions/inotifywait
index acfd14d2448..a0692958dc3 100644
--- a/completions/inotifywait
+++ b/completions/inotifywait
@@ -5,10 +5,9 @@ _comp_cmd_inotifywait__events()
     # Expecting line with "Events:", followed by ones starting with one
     # tab. Word following the tab is event name, others are line
     # wrapped explanations.
-    COMPREPLY+=($(compgen -W "$("$1" --help 2>/dev/null |
+    _comp_compgen -a split -- "$("$1" --help 2>/dev/null |
         command sed -e '/^Events:/,/^[^'$'\t'']/!d' \
-            -ne 's/^'$'\t''\([^ '$'\t'']\{1,\}\)[ '$'\t''].*/\1/p')" \
-        -- "$cur"))
+            -ne 's/^'$'\t''\([^ '$'\t'']\{1,\}\)[ '$'\t''].*/\1/p')"
 }
 
 _comp_cmd_inotifywait()
diff --git a/completions/insmod b/completions/insmod
index e5918eb57ef..2c02f3f67d4 100644
--- a/completions/insmod
+++ b/completions/insmod
@@ -9,8 +9,8 @@ _comp_cmd_insmod()
     if ((cword == 1)); then
         _comp_compgen_filedir '@(?(k)o?(.[gx]z|.zst))'
     else # do module parameter completion
-        COMPREPLY=($(compgen -W "$(PATH="$PATH:/sbin" modinfo \
-            -p "${words[1]}" 2>/dev/null | cut -d: -f1)" -- "$cur"))
+        _comp_compgen_split -- "$(PATH="$PATH:/sbin" modinfo \
+            -p "${words[1]}" 2>/dev/null | cut -d: -f1)"
     fi
 } &&
     complete -F _comp_cmd_insmod insmod insmod.static
diff --git a/completions/invoke-rc.d b/completions/invoke-rc.d
index 6119c5380cb..486fb487f78 100644
--- a/completions/invoke-rc.d
+++ b/completions/invoke-rc.d
@@ -28,9 +28,9 @@ _comp_cmd_invoke_rc_d()
         ((${#COMPREPLY[@]})) &&
             _comp_compgen -- -W '"${COMPREPLY[@]}"'
     elif [[ -x $sysvdir/$prev ]]; then
-        COMPREPLY=($(compgen -W '`command sed -e "y/|/ /" \
-            -ne "s/^.*Usage:[ ]*[^ ]*[ ]*{*\([^}\"]*\).*$/\1/p" \
-            "$sysvdir/$prev"`' -- "$cur"))
+        _comp_compgen_split -- "$(command sed -e 'y/|/ /' \
+            -ne 's/^.*Usage:[ ]*[^ ]*[ ]*{*\([^}"]*\).*$/\1/p' \
+            "$sysvdir/$prev")"
     else
         COMPREPLY=()
     fi
diff --git a/completions/ip b/completions/ip
index 914f9d5ed74..67b43e6a94f 100644
--- a/completions/ip
+++ b/completions/ip
@@ -2,18 +2,17 @@
 
 _comp_cmd_ip__iproute2_etc()
 {
-    COMPREPLY+=($(compgen -W \
-        "$(awk '!/#/ { print $2 }' "/etc/iproute2/$1" 2>/dev/null)" \
-        -- "$cur"))
+    _comp_compgen -a split -- "$(awk '!/#/ { print $2 }' "/etc/iproute2/$1" \
+        2>/dev/null)"
 }
 
 _comp_cmd_ip__netns()
 {
-    COMPREPLY=($(compgen -W "$(
+    _comp_compgen_split -- "$(
         {
             ${1-ip} -c=never netns list 2>/dev/null || ${1-ip} netns list
         } | awk '{print $1}'
-    )" -- "$cur"))
+    )"
 }
 
 _comp_cmd_ip()
@@ -65,7 +64,7 @@ _comp_cmd_ip()
                 )"
                 ;;
             *)
-                COMPREPLY=($(compgen -W "help $(
+                _comp_compgen_split -- "help $(
                     {
                         $1 -c=never help || $1 help
                     } 2>&1 | command sed -e \
@@ -73,7 +72,7 @@ _comp_cmd_ip()
                         's/.*{//' -e \
                         's/}.*//' -e \
                         's/|//g'
-                )" -- "$cur"))
+                )"
                 ;;
         esac
         return
@@ -210,16 +209,18 @@ _comp_cmd_ip()
                     ;;
                 a | add | d | del | change | append | r | replace | monitor)
                     if [[ $prev == via ]]; then
-                        COMPREPLY=($(compgen -W "$(
+                        _comp_compgen_split -- "$(
                             {
                                 $1 -c=never r 2>/dev/null || $1 r
                             } | command sed -ne \
                                 's/.*via \([0-9.]*\).*/\1/p'
-                        )" -- "$cur"))
+                        )"
                     elif [[ $prev == "$subcmd" ]]; then
-                        COMPREPLY=($(compgen -W "table default $({
-                            $1 -c=never r 2>/dev/null || $1 r
-                        } | cut -d ' ' -f 1)" -- "$cur"))
+                        _comp_compgen_split -- "table default $(
+                            {
+                                $1 -c=never r 2>/dev/null || $1 r
+                            } | cut -d ' ' -f 1
+                        )"
                     elif [[ $prev == dev ]]; then
                         _available_interfaces -a
                     elif [[ $prev == table ]]; then
diff --git a/completions/ipmitool b/completions/ipmitool
index 932741210ab..bcf8c83e4c1 100644
--- a/completions/ipmitool
+++ b/completions/ipmitool
@@ -2,8 +2,8 @@
 
 _comp_cmd_ipmitool__singleline_help()
 {
-    COMPREPLY=($(compgen -W "$("$1" "$2" 2>&1 |
-        command sed -ne 's/[,\r]//g' -e 's/^.*[Cc]ommands://p')" -- "$cur"))
+    _comp_compgen_split -- "$("$1" "$2" 2>&1 |
+        command sed -ne 's/[,\r]//g' -e 's/^.*[Cc]ommands://p')"
 }
 
 _comp_cmd_ipmitool()
@@ -23,10 +23,9 @@ _comp_cmd_ipmitool()
             return
             ;;
         -*I)
-            COMPREPLY=($(compgen -W "$("$1" -h 2>&1 |
+            _comp_compgen_split -- "$("$1" -h 2>&1 |
                 command sed -e '/^Interfaces:/,/^[[:space:]]*$/!d' \
-                    -ne 's/^[[:space:]]\{1,\}\([^[:space:]]\{1,\}\).*/\1/p')" \
-                -- "$cur"))
+                    -ne 's/^[[:space:]]\{1,\}\([^[:space:]]\{1,\}\).*/\1/p')"
             return
             ;;
         -*H)
@@ -50,8 +49,8 @@ _comp_cmd_ipmitool()
             return
             ;;
         -*o)
-            COMPREPLY=($(compgen -W "$("$1" -o list 2>&1 |
-                awk '/^[ \t]+/ { print $1 }') list" -- "$cur"))
+            _comp_compgen_split -- "$("$1" -o list 2>&1 |
+                awk '/^[ \t]+/ { print $1 }') list"
             return
             ;;
     esac
diff --git a/completions/iptables b/completions/iptables
index 0948d8f355e..d0c0ec1e632 100644
--- a/completions/iptables
+++ b/completions/iptables
@@ -6,6 +6,7 @@ _comp_cmd_iptables()
     _comp_initialize -s -- "$@" || return
 
     local table="" chain='s/^Chain \([^ ]\{1,\}\).*$/\1/p'
+    local targets='ACCEPT DROP LOG ULOG REJECT'
 
     local IFS=$' \t\n' # for ${table:+-t "$table"}
     [[ ${words[*]} =~ [[:space:]]-(t|-table=?)[[:space:]]*([^[:space:]]+) ]] &&
@@ -13,28 +14,30 @@ _comp_cmd_iptables()
 
     case $prev in
         -*[AIDRPFXLZ])
-            COMPREPLY=($(compgen -W '`"$1" ${table:+-t "$table"} -nL 2>/dev/null | \
-                command sed -ne "s/^Chain \([^ ]\{1,\}\).*$/\1/p"`' -- "$cur"))
+            _comp_compgen_split -- "$(
+                "$1" ${table:+-t "$table"} -nL 2>/dev/null |
+                    command sed -ne 's/^Chain \([^ ]\{1,\}\).*$/\1/p'
+            )"
             ;;
         -*t)
             _comp_compgen -- -W 'nat filter mangle'
             ;;
         -j)
             if [[ $table == "filter" || ! $table ]]; then
-                COMPREPLY=($(compgen -W 'ACCEPT DROP LOG ULOG REJECT
-                `"$1" ${table:+-t "$table"} -nL 2>/dev/null | command sed -ne "$chain" \
-                -e "s/INPUT|OUTPUT|FORWARD|PREROUTING|POSTROUTING//"`' -- \
-                    "$cur"))
+                _comp_compgen -- -W '$targets'
+                _comp_compgen -a split -- "$("$1" ${table:+-t "$table"} -nL \
+                    2>/dev/null | command sed -ne "$chain" \
+                    -e 's/INPUT|OUTPUT|FORWARD|PREROUTING|POSTROUTING//')"
             elif [[ $table == "nat" ]]; then
-                COMPREPLY=($(compgen -W 'ACCEPT DROP LOG ULOG REJECT MIRROR SNAT
-                DNAT MASQUERADE `"$1" -t "$table" -nL 2>/dev/null | \
-                command sed -ne "$chain" -e "s/OUTPUT|PREROUTING|POSTROUTING//"`' \
-                    -- "$cur"))
+                _comp_compgen -- -W '$targets MIRROR SNAT DNAT MASQUERADE'
+                _comp_compgen -a split -- "$("$1" -t "$table" -nL 2>/dev/null |
+                    command sed -ne "$chain" \
+                        -e 's/OUTPUT|PREROUTING|POSTROUTING//')"
             elif [[ $table == "mangle" ]]; then
-                COMPREPLY=($(compgen -W 'ACCEPT DROP LOG ULOG REJECT MARK TOS
-                `"$1" -t "$table" -nL 2>/dev/null | command sed -ne "$chain" \
-                -e "s/INPUT|OUTPUT|FORWARD|PREROUTING|POSTROUTING//"`' -- \
-                    "$cur"))
+                _comp_compgen -- -W '$targets MARK TOS'
+                _comp_compgen -a split -- "$("$1" -t "$table" -nL 2>/dev/null |
+                    command sed -ne "$chain" \
+                        -e 's/INPUT|OUTPUT|FORWARD|PREROUTING|POSTROUTING//')"
             fi
             ;;
         *)
diff --git a/completions/ipv6calc b/completions/ipv6calc
index e9bf070a3a0..7cf7d82338e 100644
--- a/completions/ipv6calc
+++ b/completions/ipv6calc
@@ -13,9 +13,8 @@ _comp_cmd_ipv6calc()
             ;;
         --in | --out | --action | -${noargopts}[IOA])
             # With ipv6calc < 0.73.0, -m does nothing here, so use sed instead.
-            COMPREPLY=($(compgen -W "$("$1" "$prev" -h 2>&1 |
-                command sed -ne 's/^[[:space:]]\{1,\}\([^[:space:]:]\{1,\}\)[[:space:]]*:.*/\1/p')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" "$prev" -h 2>&1 |
+                command sed -ne 's/^[[:space:]]\{1,\}\([^[:space:]:]\{1,\}\)[[:space:]]*:.*/\1/p')"
             return
             ;;
         --db-geoip | --db-ip2location-ipv4 | --db-ip2location-ipv6)
diff --git a/completions/iwconfig b/completions/iwconfig
index 6dd7b8c4abf..e31f3314784 100644
--- a/completions/iwconfig
+++ b/completions/iwconfig
@@ -14,9 +14,8 @@ _comp_cmd_iwconfig()
         essid)
             _comp_compgen -- -W 'on off any'
             if [[ ${BASH_COMPLETION_CMD_IWCONFIG_SCAN-${COMP_IWLIST_SCAN-}} ]]; then
-                COMPREPLY+=($(compgen -W \
-                    "$(iwlist "${words[1]}" scan |
-                        awk -F'\"' '/ESSID/ {print $2}')" -- "$cur"))
+                _comp_compgen -a split -- "$(iwlist "${words[1]}" scan |
+                    awk -F'\"' '/ESSID/ {print $2}')"
             fi
             return
             ;;
@@ -25,30 +24,28 @@ _comp_cmd_iwconfig()
             return
             ;;
         channel)
-            COMPREPLY=($(compgen -W "$(iwlist "${words[1]}" channel |
-                awk '/^[ \t]*Channel/ {print $2}')" -- "$cur"))
+            _comp_compgen_split -- "$(iwlist "${words[1]}" channel |
+                awk '/^[ \t]*Channel/ {print $2}')"
             return
             ;;
 
         freq)
-            COMPREPLY=($(compgen -W "$(iwlist "${words[1]}" channel |
-                awk '/^[ \t]*Channel/ {print $4"G"}')" -- "$cur"))
+            _comp_compgen_split -- "$(iwlist "${words[1]}" channel |
+                awk '/^[ \t]*Channel/ {print $4"G"}')"
             return
             ;;
         ap)
             _comp_compgen -- -W 'on off any'
             if [[ ${BASH_COMPLETION_CMD_IWCONFIG_SCAN-${COMP_IWLIST_SCAN-}} ]]; then
-                COMPREPLY+=($(compgen -W \
-                    "$(iwlist "${words[1]}" scan |
-                        awk -F ': ' '/Address/ {print $2}')" -- "$cur"))
+                _comp_compgen -a split -- "$(iwlist "${words[1]}" scan |
+                    awk -F ': ' '/Address/ {print $2}')"
             fi
             return
             ;;
         rate)
             _comp_compgen -- -W 'auto fixed'
-            COMPREPLY+=($(compgen -W \
-                "$(iwlist "${words[1]}" rate |
-                    awk '/^[ \t]*[0-9]/ {print $1"M"}')" -- "$cur"))
+            _comp_compgen -a split -- "$(iwlist "${words[1]}" rate |
+                awk '/^[ \t]*[0-9]/ {print $1"M"}')"
             return
             ;;
         rts | frag)
diff --git a/completions/kldunload b/completions/kldunload
index 5ed6a67d646..3870720ba26 100644
--- a/completions/kldunload
+++ b/completions/kldunload
@@ -7,7 +7,7 @@ _comp_cmd_kldunload()
     local cur prev words cword comp_args
     _comp_initialize -- "$@" || return
 
-    COMPREPLY=($(compgen -W '$(kldstat)' -X 'kernel' -X '!*.ko' -- "$cur"))
+    _comp_compgen_split -X '!*.ko' -- "$(kldstat)"
     COMPREPLY=(${COMPREPLY[@]%.ko})
 } &&
     complete -F _comp_cmd_kldunload kldunload
diff --git a/completions/koji b/completions/koji
index aeb77f33687..3d3078e18b8 100644
--- a/completions/koji
+++ b/completions/koji
@@ -2,8 +2,7 @@
 
 _comp_cmd_koji__search()
 {
-    COMPREPLY+=($(compgen -W \
-        '$("$1" -q search "$2" "$cur*" 2>/dev/null)' -- "$cur"))
+    _comp_compgen -a split -- "$("$1" -q search "$2" "$cur*" 2>/dev/null)"
 }
 
 _comp_cmd_koji__build()
@@ -23,13 +22,13 @@ _comp_cmd_koji__user()
 
 _comp_cmd_koji__tag()
 {
-    COMPREPLY+=($(compgen -W '$("$1" -q list-tags 2>/dev/null)' -- "$cur"))
+    _comp_compgen -a split -- "$("$1" -q list-tags 2>/dev/null)"
 }
 
 _comp_cmd_koji__target()
 {
-    COMPREPLY+=($(compgen -W '$("$1" -q list-targets 2>/dev/null |
-        awk "{ print \$1 }")' -- "$cur"))
+    _comp_compgen -a split -- "$("$1" -q list-targets 2>/dev/null |
+        awk '{ print $1 }')"
 }
 
 _comp_cmd_koji()
@@ -238,8 +237,8 @@ _comp_cmd_koji()
         _comp_compgen_help
         [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
     elif [[ ! $has_command ]]; then
-        COMPREPLY=($(compgen -W '$("$1" --help-commands 2>/dev/null | \
-            awk "/^(  +|\t)/ { print \$1 }")' -- "$cur"))
+        _comp_compgen_split -- "$("$1" --help-commands 2>/dev/null |
+            awk '/^(  +|\t)/ { print $1 }')"
     fi
 } &&
     complete -F _comp_cmd_koji koji arm-koji ppc-koji s390-koji sparc-koji
diff --git a/completions/ktutil b/completions/ktutil
index 2cab8cff95e..3d4dd401ae1 100644
--- a/completions/ktutil
+++ b/completions/ktutil
@@ -2,14 +2,14 @@
 
 _comp_cmd_ktutil__heimdal_principals()
 {
-    COMPREPLY=($(compgen -W "$(kadmin -l dump 2>/dev/null |
-        awk '{print $1}')" -- "$cur"))
+    _comp_compgen_split -- "$(kadmin -l dump 2>/dev/null |
+        awk '{print $1}')"
 }
 
 _comp_cmd_ktutil__heimdal_realms()
 {
-    COMPREPLY=($(compgen -W "$(kadmin -l dump 2>/dev/null |
-        awk '{print $1}' | awk -F@ '{print $2}')" -- "$cur"))
+    _comp_compgen_split -- "$(kadmin -l dump 2>/dev/null |
+        awk '{print $1}' | awk -F@ '{print $2}')"
 }
 
 _comp_cmd_ktutil__heimdal_encodings()
diff --git a/completions/lftp b/completions/lftp
index ee1ec941d12..7a8801e7487 100644
--- a/completions/lftp
+++ b/completions/lftp
@@ -22,7 +22,7 @@ _comp_cmd_lftp()
         return
     fi
 
-    COMPREPLY=($(compgen -W '$("$1" -c "bookmark list" 2>/dev/null)' -- "$cur"))
+    _comp_compgen_split -- "$("$1" -c "bookmark list" 2>/dev/null)"
     _known_hosts_real -- "$cur"
 } &&
     complete -F _comp_cmd_lftp lftp
diff --git a/completions/lilo b/completions/lilo
index 738aacb98a4..e519bf29aec 100644
--- a/completions/lilo
+++ b/completions/lilo
@@ -2,9 +2,8 @@
 
 _comp_cmd_lilo__labels()
 {
-    COMPREPLY=($(compgen -W "$(awk -F= '$1 ~ /^[ \t]*label$/ {print $2}' \
-        "${1:-/etc/lilo.conf}" 2>/dev/null | command sed -e 's/\"//g')" \
-        -- "$cur"))
+    _comp_compgen_split -- "$(awk -F= '$1 ~ /^[ \t]*label$/ {print $2}' \
+        "${1:-/etc/lilo.conf}" 2>/dev/null | command sed -e 's/\"//g')"
 }
 
 _comp_cmd_lilo()
diff --git a/completions/links b/completions/links
index 0b399f8bd92..c9f9b466bdc 100644
--- a/completions/links
+++ b/completions/links
@@ -88,7 +88,7 @@ _comp_cmd_links()
     local dir
     for dir in .links .links2; do
         if [[ -r ~/$dir/links.his ]]; then
-            COMPREPLY+=($(compgen -W '$(cat ~/$dir/links.his)' -- "$cur"))
+            _comp_compgen -a split -- "$(cat ~/$dir/links.his)"
             _comp_ltrim_colon_completions "$cur"
         fi
     done
diff --git a/completions/list_lists b/completions/list_lists
index c8a82844de7..4062c6267f2 100644
--- a/completions/list_lists
+++ b/completions/list_lists
@@ -3,7 +3,7 @@
 # @since 2.12
 _comp_xfunc_list_lists_mailman_lists()
 {
-    COMPREPLY=($(compgen -W '$(list_lists -b 2>/dev/null)' -- "$cur"))
+    _comp_compgen_split -- "$(list_lists -b 2>/dev/null)"
 }
 
 _comp_deprecate_func 2.12 _mailman_lists _comp_xfunc_list_lists_mailman_lists
diff --git a/completions/locale-gen b/completions/locale-gen
index 7a7609cd0a9..60fa66df236 100644
--- a/completions/locale-gen
+++ b/completions/locale-gen
@@ -23,9 +23,9 @@ _comp_cmd_locale_gen()
         return
     fi
 
-    COMPREPLY=($(compgen -W \
-        '$(awk "{ print \$1 }" /usr/share/i18n/SUPPORTED 2>/dev/null)' \
-        -- "$cur"))
+    _comp_compgen_split -- "$(
+        awk '{ print $1 }' /usr/share/i18n/SUPPORTED 2>/dev/null
+    )"
 } &&
     complete -F _comp_cmd_locale_gen locale-gen
 
diff --git a/completions/lpq b/completions/lpq
index 89f5e1e70c3..d9c29bba3b1 100644
--- a/completions/lpq
+++ b/completions/lpq
@@ -7,7 +7,7 @@ _comp_cmd_lpq()
 
     case $prev in
         -P)
-            COMPREPLY=($(compgen -W "$(lpstat -a 2>/dev/null | cut -d' ' -f1)" -- "$cur"))
+            _comp_compgen_split -- "$(lpstat -a 2>/dev/null | cut -d' ' -f1)"
             return
             ;;
         -U)
diff --git a/completions/lpr b/completions/lpr
index 86ae3344be9..746df285b24 100644
--- a/completions/lpr
+++ b/completions/lpr
@@ -7,7 +7,7 @@ _comp_cmd_lpr()
 
     case $prev in
         -P)
-            COMPREPLY=($(compgen -W "$(lpstat -a 2>/dev/null | cut -d' ' -f1)" -- "$cur"))
+            _comp_compgen_split -- "$(lpstat -a 2>/dev/null | cut -d' ' -f1)"
             return
             ;;
         -U)
diff --git a/completions/lspci b/completions/lspci
index 791a8faea37..16d61956f61 100644
--- a/completions/lspci
+++ b/completions/lspci
@@ -18,8 +18,7 @@ _comp_cmd_lspci()
             return
             ;;
         -*A)
-            COMPREPLY=($(compgen -W '$("$1" -A help | command grep -vF :)' \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" -A help | command grep -vF :)"
             return
             ;;
         -*H)
diff --git a/completions/lvm b/completions/lvm
index 64b6c63cceb..647c1e94908 100644
--- a/completions/lvm
+++ b/completions/lvm
@@ -7,26 +7,26 @@ _comp_cmd_lvm__filedir()
 
 _comp_cmd_lvm__volumegroups()
 {
-    COMPREPLY=($(compgen -W "$(vgscan 2>/dev/null |
-        command sed -n -e 's|.*Found.*"\(.*\)".*$|\1|p')" -- "$cur"))
+    _comp_compgen_split -- "$(vgscan 2>/dev/null |
+        command sed -n -e 's|.*Found.*"\(.*\)".*$|\1|p')"
 }
 
 _comp_cmd_lvm__physicalvolumes_all()
 {
-    COMPREPLY=($(compgen -W "$(pvscan 2>/dev/null |
-        command sed -n -e 's|^.*PV \([^ ]*\) .*|\1|p')" -- "$cur"))
+    _comp_compgen_split -- "$(pvscan 2>/dev/null |
+        command sed -n -e 's|^.*PV \([^ ]*\) .*|\1|p')"
 }
 
 _comp_cmd_lvm__physicalvolumes()
 {
-    COMPREPLY=($(compgen -W "$(pvscan 2>/dev/null |
-        command sed -n -e 's|^.*PV \(.*\) VG.*$|\1|p')" -- "$cur"))
+    _comp_compgen_split -- "$(pvscan 2>/dev/null |
+        command sed -n -e 's|^.*PV \(.*\) VG.*$|\1|p')"
 }
 
 _comp_cmd_lvm__logicalvolumes()
 {
-    COMPREPLY=($(compgen -W "$(lvscan 2>/dev/null |
-        command sed -n -e "s|^.*'\(.*\)'.*$|\1|p")" -- "$cur"))
+    _comp_compgen_split -- "$(lvscan 2>/dev/null |
+        command sed -n -e "s|^.*'\(.*\)'.*$|\1|p")"
     if [[ $cur == /dev/mapper/* ]]; then
         _comp_compgen -a filedir
         local i
diff --git a/completions/mcrypt b/completions/mcrypt
index abdd4fb7b7e..95451fde942 100644
--- a/completions/mcrypt
+++ b/completions/mcrypt
@@ -12,23 +12,21 @@ _comp_cmd_mcrypt()
             return
             ;;
         -o | --keymode)
-            COMPREPLY=($(compgen -W '$("$1" --list-keymodes 2>/dev/null )' \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-keymodes 2>/dev/null)"
             return
             ;;
         -m | --mode)
-            COMPREPLY=($(compgen -W "$("$1" --list 2>/dev/null | cut -d: -f2-)" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list 2>/dev/null | cut -d: -f2-)"
             return
             ;;
         -a | --algorithm)
-            COMPREPLY=($(compgen -W "$("$1" --list 2>/dev/null |
-                awk '{print $1}')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list 2>/dev/null |
+                awk '{print $1}')"
             return
             ;;
         -h | --hash)
-            COMPREPLY=($(compgen -W '$("$1" --list-hash 2>/dev/null | \
-                command sed -e 1d)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-hash 2>/dev/null |
+                command sed -e 1d)"
             return
             ;;
         -k | -s | --key | --keysize)
diff --git a/completions/medusa b/completions/medusa
index 25542bc3ffd..6c588f38539 100644
--- a/completions/medusa
+++ b/completions/medusa
@@ -15,8 +15,8 @@ _comp_cmd_medusa()
             return
             ;;
         -*M)
-            COMPREPLY=($(compgen -W "$("$1" -d | awk '/^ +\+/ {print $2}' |
-                command sed -e 's/\.mod$//')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" -d | awk '/^ +\+/ {print $2}' |
+                command sed -e 's/\.mod$//')"
             return
             ;;
     esac
diff --git a/completions/modprobe b/completions/modprobe
index bbf799a34f1..8d86cafcbab 100644
--- a/completions/modprobe
+++ b/completions/modprobe
@@ -96,9 +96,9 @@ _comp_cmd_modprobe()
                         _comp_compgen -- -W "$choices"
                     fi
                 else
-                    COMPREPLY=($(compgen -S = -W "$(PATH="$PATH:/sbin" \
+                    _comp_compgen_split -S = -- "$(PATH="$PATH:/sbin" \
                         modinfo -p "$module" 2>/dev/null |
-                        awk -F: '!/^[ \t]/ { print $1 }')" -- "$cur"))
+                        awk -F: '!/^[ \t]/ { print $1 }')"
                     [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
                 fi
             else
diff --git a/completions/mplayer b/completions/mplayer
index a9baae784f5..6d787e956cb 100644
--- a/completions/mplayer
+++ b/completions/mplayer
@@ -3,9 +3,9 @@
 _comp_cmd_mplayer__options()
 {
     cur=${cur%\\}
-    COMPREPLY=($(compgen -W "$("$1" -noconfig all "$2" help 2>/dev/null |
+    _comp_compgen_split -- "$("$1" -noconfig all "$2" help 2>/dev/null |
         command sed -e '/^Available/,/^$/!d' -e '/^Available/d' | awk '{print $1}' |
-        command sed -e 's/:$//' -e 's/^'"${2#-}"'$//' -e 's/<.*//')" -- "$cur"))
+        command sed -e 's/:$//' -e 's/^'"${2#-}"'$//' -e 's/<.*//')"
 }
 
 _comp_cmd_mplayer()
@@ -35,8 +35,7 @@ _comp_cmd_mplayer()
             else
                 _comp_compgen_filedir ttf
             fi
-            local IFS=$'\n'
-            COMPREPLY+=($(compgen -W '$(fc-list 2>/dev/null)' -- "$cur"))
+            _comp_compgen -a split -l -- "$(fc-list 2>/dev/null)"
             return
             ;;
         -sub | -sub-file)
@@ -268,10 +267,10 @@ _comp_cmd_mplayer()
 
     case $cur in
         -*)
-            COMPREPLY=($(compgen -W '$("$cmd" -noconfig all -list-options 2>/dev/null | \
+            _comp_compgen_split -- "$("$cmd" -noconfig all -list-options 2>/dev/null |
                 command sed -ne "1,/^[[:space:]]*Name/d" \
                     -e "s/^[[:space:]]*/-/" -e "s/[[:space:]:].*//" \
-                    -e "/^-\(Total\|.*\*\)\{0,1\}$/!p")' -- "$cur"))
+                    -e "/^-\(Total\|.*\*\)\{0,1\}$/!p")"
             ;;
         *)
             _comp_compgen_filedir '@(m?(j)p?(e)g|M?(J)P?(E)G|wm[av]|WM[AV]|avi|AVI|asf|ASF|vob|VOB|bin|BIN|dat|DAT|vcd|VCD|ps|PS|pes|PES|fl[iv]|FL[IV]|fxm|FXM|viv|VIV|rm?(j)|RM?(J)|ra?(m)|RA?(M)|yuv|YUV|mov|MOV|qt|QT|mp[234]|MP[234]|m?(p)4[av]|M?(P)4[AV]|og[gmavx]|OG[GMAVX]|w?(a)v|W?(A)V|dump|DUMP|mk[av]|MK[AV]|aac|AAC|m2v|M2V|dv|DV|rmvb|RMVB|mid|MID|t[ps]|T[PS]|3g[p2]|3gpp?(2)|mpc|MPC|flac|FLAC|vro|VRO|divx|DIVX|aif?(f)|AIF?(F)|m2t?(s)|M2T?(S)|mts|MTS|vdr|VDR|xvid|XVID|ape|APE|gif|GIF|nut|NUT|bik|BIK|web[am]|WEB[AM]|amr|AMR|awb|AWB|iso|ISO|opus|OPUS|m[eo]d|M[EO]D|xm|XM|it|IT|s[t3]m|S[T3]M|mtm|MTM|w64|W64)?(.@(crdownload|part))'
diff --git a/completions/msynctool b/completions/msynctool
index d2ff5ecad30..76c58758556 100644
--- a/completions/msynctool
+++ b/completions/msynctool
@@ -7,27 +7,23 @@ _comp_cmd_msynctool()
 
     case $words in
         --configure)
-            COMPREPLY=($(compgen -W "$("$1" --showgroup \
-                "$prev" | awk '/^Member/ {print $2}' | command sed \
-                -e 's/:$//')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" --showgroup "$prev" |
+                awk '/^Member/ {print $2}' | command sed -e 's/:$//')"
             return
             ;;
         --addmember)
-            COMPREPLY=($(compgen -W '$("$1" --listplugins \
-                | command sed -e 1d)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --listplugins | command sed -e 1d)"
             return
             ;;
     esac
 
     case $prev in
         --configure | --addgroup | --delgroup | --showgroup | --sync | --addmember)
-            COMPREPLY=($(compgen -W '$("$1" --listgroups \
-                | command sed -e 1d)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --listgroups | command sed -e 1d)"
             return
             ;;
         --showformats | --filter-objtype | --slow-sync)
-            COMPREPLY=($(compgen -W '$("$1" --listobjects \
-                | command sed -e 1d)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --listobjects | command sed -e 1d)"
             return
             ;;
     esac
diff --git a/completions/munin-run b/completions/munin-run
index f781bcf5a9e..c514a01d5de 100644
--- a/completions/munin-run
+++ b/completions/munin-run
@@ -19,8 +19,7 @@ _comp_cmd_munin_run()
     if [[ $cur == -* ]]; then
         _comp_compgen_help
     else
-        COMPREPLY=($(compgen -W \
-            '$(command ls /etc/munin/plugins 2>/dev/null)' -- "$cur"))
+        _comp_compgen_split -- "$(command ls /etc/munin/plugins 2>/dev/null)"
     fi
 } &&
     complete -F _comp_cmd_munin_run munin-run
diff --git a/completions/munindoc b/completions/munindoc
index f2024928eb4..4a1b4c668e4 100644
--- a/completions/munindoc
+++ b/completions/munindoc
@@ -5,8 +5,7 @@ _comp_cmd_munindoc()
     local cur prev words cword comp_args
     _comp_initialize -- "$@" || return
 
-    COMPREPLY=($(compgen -W \
-        '$(command ls /usr/share/munin/plugins 2>/dev/null)' -- "$cur"))
+    _comp_compgen_split -- "$(command ls /usr/share/munin/plugins 2>/dev/null)"
 } &&
     complete -F _comp_cmd_munindoc munindoc
 
diff --git a/completions/mysql b/completions/mysql
index 27acad1da0b..1a4aa992518 100644
--- a/completions/mysql
+++ b/completions/mysql
@@ -30,7 +30,8 @@ _comp_cmd_mysql()
             return
             ;;
         --database | -${noargopts}D)
-            COMPREPLY=($(compgen -W "$(mysqlshow 2>/dev/null | command sed -ne '2d' -e 's/^|.\([^|]*\)|.*/\1/p')" -- "$cur"))
+            _comp_compgen_split -- "$(mysqlshow 2>/dev/null |
+                command sed -ne '2d' -e 's/^|.\([^|]*\)|.*/\1/p')"
             return
             ;;
 
@@ -96,9 +97,8 @@ _comp_cmd_mysql()
             ;;
     esac
 
-    COMPREPLY=($(compgen -W \
-        "$(mysqlshow 2>/dev/null | command sed -ne '2d' -e 's/^|.\([^|]*\)|.*/\1/p')" \
-        -- "$cur"))
+    _comp_compgen_split -- "$(mysqlshow 2>/dev/null |
+        command sed -ne '2d' -e 's/^|.\([^|]*\)|.*/\1/p')"
 } &&
     complete -F _comp_cmd_mysql mysql
 
diff --git a/completions/ncftp b/completions/ncftp
index 89e8c72d92e..60218c11847 100644
--- a/completions/ncftp
+++ b/completions/ncftp
@@ -17,8 +17,8 @@ _comp_cmd_ncftp()
     fi
 
     if [[ $cword -eq 1 && -f ~/.ncftp/bookmarks ]]; then
-        COMPREPLY=($(compgen -W '$(command sed -ne "s/^\([^,]\{1,\}\),.*$/\1/p" \
-            ~/.ncftp/bookmarks)' -- "$cur"))
+        _comp_compgen_split -- "$(command sed -ne \
+            's/^\([^,]\{1,\}\),.*$/\1/p' ~/.ncftp/bookmarks)"
     fi
 
 } &&
diff --git a/completions/nmap b/completions/nmap
index 70ce3700eb3..a3131657516 100644
--- a/completions/nmap
+++ b/completions/nmap
@@ -35,7 +35,7 @@ _comp_cmd_nmap()
         # expand --foo/bar to --foo --bar
         # strip everything following a non-option name or = char
         # TODO: should expand -T<0-5> to -T0 ... -T5
-        COMPREPLY=($(compgen -W "$(
+        _comp_compgen_split -- "$(
             "$1" --help 2>&1 | command sed \
                 -e "s/:.*$//" \
                 -e "s/=.*$/=/" \
@@ -44,8 +44,7 @@ _comp_cmd_nmap()
                 -e "/^[[:space:]]*-[^-]/s/\/\([^-]\)/ -\1/g" \
                 -e "/^[[:space:]]*--/s/\/\([^-]\)/ --\1/g" \
                 -e "s/[^[:space:]a-zA-Z0-9=-].*$//"
-        )" \
-            -- "$cur"))
+        )"
         [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
     else
         _known_hosts_real -- "$cur"
diff --git a/completions/openssl b/completions/openssl
index 69a5916a268..0dc8aad8d8a 100644
--- a/completions/openssl
+++ b/completions/openssl
@@ -22,7 +22,7 @@ _comp_cmd_openssl__sections()
 
     [[ ! -f $config ]] && return
 
-    COMPREPLY=($(compgen -W "$(awk '/\[.*\]/ {print $2}' "$config")" -- "$cur"))
+    _comp_compgen_split -- "$(awk '/\[.*\]/ {print $2}' "$config")"
 }
 
 # TODO:API: rename per conventions, rework to use vars rather than outputting
@@ -104,7 +104,7 @@ _comp_cmd_openssl()
                 return
                 ;;
             -cipher)
-                COMPREPLY=($(IFS=: compgen -W "$("$1" ciphers)" -- "$cur"))
+                _comp_compgen_split -F : -- "$("$1" ciphers)"
                 return
                 ;;
             -kdf)
diff --git a/completions/pdftotext b/completions/pdftotext
index 34b4939bf1c..a99fd400e4f 100644
--- a/completions/pdftotext
+++ b/completions/pdftotext
@@ -11,8 +11,8 @@ _comp_cmd_pdftotext()
             return
             ;;
         -enc)
-            COMPREPLY=($(compgen -W '$("$1" -listenc 2>/dev/null |
-                command sed -e 1d)' -- "$cur"))
+            _comp_compgen_split -- "$("$1" -listenc 2>/dev/null |
+                command sed -e 1d)"
             return
             ;;
         -eol)
diff --git a/completions/perl b/completions/perl
index d23d0f8ada4..0938d736ae3 100644
--- a/completions/perl
+++ b/completions/perl
@@ -2,9 +2,8 @@
 
 _comp_cmd_perl__helper()
 {
-    COMPREPLY=($(compgen -P "$prefix" -W \
-        "$("${1:-perl}" "${BASH_SOURCE[0]%/*}/../helpers/perl" "$2" "$cur")" \
-        -- "$cur"))
+    _comp_compgen_split -P "$prefix" -- "$("${1:-perl}" \
+        "${BASH_SOURCE[0]%/*}/../helpers/perl" "$2" "$cur")"
     [[ $2 == functions ]] || _comp_ltrim_colon_completions "$prefix$cur"
 }
 
@@ -48,10 +47,10 @@ _comp_cmd_perl()
                 if [[ $cur == :* ]]; then
                     temp="${cur##+(:)}"
                     prefix+=${cur%"$temp"}
-                    local IFS=$'\n'
-                    COMPREPLY=($(compgen -P "$prefix" -W \
-                        '$("$1" -MConfig -e "print join \"\\n\",
-                           keys %Config::Config" 2>/dev/null)' -- "$temp"))
+                    _comp_compgen -c "$temp" split -lP "$prefix" -- "$(
+                        "$1" -MConfig -e 'print join "\n",
+                           keys %Config::Config' 2>/dev/null
+                    )"
                     _comp_ltrim_colon_completions "$prefix$temp"
                 fi
                 return
@@ -131,11 +130,9 @@ _comp_cmd_perldoc()
         if [[ $cur != @(*/|[.~])* ]]; then
             _comp_cmd_perl__helper "" perldocs
             if [[ $cur == p* ]]; then
-                COMPREPLY+=($(compgen -W \
-                    '$(PERLDOC_PAGER=cat "$1" -u perl |  \
-                       command sed -ne "/perl.*Perl overview/,/perlwin32/p" | \
-                       awk "\$NF=2 && \$1 ~ /^perl/ { print \$1 }")' \
-                    -- "$cur"))
+                _comp_compgen -a split -- "$(PERLDOC_PAGER=cat "$1" -u perl |
+                    command sed -ne '/perl.*Perl overview/,/perlwin32/p' |
+                    awk '$NF=2 && $1 ~ /^perl/ { print $1 }')"
             fi
         fi
         _comp_compgen -a filedir 'p@([lm]|od)'
diff --git a/completions/perlcritic b/completions/perlcritic
index bd04255c000..03d0fc59612 100644
--- a/completions/perlcritic
+++ b/completions/perlcritic
@@ -19,8 +19,7 @@ _comp_cmd_perlcritic()
             return
             ;;
         --theme)
-            COMPREPLY=($(compgen -W '$("$1" --list-themes 2>/dev/null)' \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --list-themes 2>/dev/null)"
             return
             ;;
         --profile-strictness)
diff --git a/completions/pgrep b/completions/pgrep
index 241c669f240..a2a68e9b987 100644
--- a/completions/pgrep
+++ b/completions/pgrep
@@ -36,12 +36,10 @@ _comp_cmd_pgrep()
             return
             ;;
         --nslist)
-            COMPREPLY=(
-                $(IFS=$' \t\n,' compgen -W '$("$1" --help 2>&1 |
-                    command sed -ne \
-                        "s/^[[:space:]]*Available namespaces://p")' \
-                    -- "${cur##*,}"))
-            ((${#COMPREPLY[@]})) &&
+            _comp_compgen -c "${cur##*,}" split -F $' \t\n,' -- "$(
+                "$1" --help 2>&1 |
+                    command sed -ne 's/^[[:space:]]*Available namespaces://p'
+            )" &&
                 _comp_delimited , -W '"${COMPREPLY[@]}"'
             return
             ;;
diff --git a/completions/pine b/completions/pine
index 51a7373d42c..1d72dabe050 100644
--- a/completions/pine
+++ b/completions/pine
@@ -24,8 +24,7 @@ _comp_cmd_pine()
     if [[ $cur == -* ]]; then
         _comp_compgen_help -- -h
     else
-        COMPREPLY=($(compgen -W '$(awk "{print \$1}" ~/.addressbook \
-            2>/dev/null)' -- "$cur"))
+        _comp_compgen_split -- "$(awk '{print $1}' ~/.addressbook 2>/dev/null)"
     fi
 } &&
     complete -F _comp_cmd_pine pine alpine
diff --git a/completions/pkg-config b/completions/pkg-config
index 0535ee5975b..2af804f5c68 100644
--- a/completions/pkg-config
+++ b/completions/pkg-config
@@ -15,9 +15,9 @@ _comp_cmd_pkg_config()
             local word
             for word in "${words[@]:1}"; do
                 if [[ $word != -* ]]; then
-                    COMPREPLY=($(compgen -W \
-                        '$("$1" "$word" --print-variables 2>/dev/null)' \
-                        -- "$cur"))
+                    _comp_compgen_split -- "$(
+                        "$1" "$word" --print-variables 2>/dev/null
+                    )"
                     break
                 fi
             done
@@ -35,8 +35,8 @@ _comp_cmd_pkg_config()
         _comp_compgen_help
         [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
     else
-        COMPREPLY=($(compgen -W "$("$1" --list-all \
-            2>/dev/null | awk '{print $1}')" -- "$cur"))
+        _comp_compgen_split -- "$("$1" --list-all 2>/dev/null |
+            awk '{print $1}')"
         _comp_compgen -a filedir pc
     fi
 } &&
diff --git a/completions/pkgrm b/completions/pkgrm
index b679c03ab33..ee7f50cbca0 100644
--- a/completions/pkgrm
+++ b/completions/pkgrm
@@ -36,7 +36,7 @@ _comp_cmd_pkgrm()
                 local opts="-a -A -n -M -R -s -v -V -Y"
                 _comp_compgen -- -W "${opts}"
             else
-                COMPREPLY=($(compgen -W "$(/bin/ls -1 "$spool")" -- "${cur}"))
+                _comp_compgen_split -- "$(/bin/ls -1 "$spool")"
             fi
             ;;
     esac
diff --git a/completions/pngfix b/completions/pngfix
index d638ccef0d5..d77d80b24a9 100644
--- a/completions/pngfix
+++ b/completions/pngfix
@@ -14,9 +14,8 @@ _comp_cmd_pngfix()
             return
             ;;
         --strip)
-            COMPREPLY=($(IFS='|' compgen -W '$("$1" --help 2>&1 |
-                command sed -ne "s/.*--strip=\[\([^]]*\)\].*/\1/p")' \
-                -- "$cur"))
+            _comp_compgen_split -F '|' -- "$("$1" --help 2>&1 |
+                command sed -ne 's/.*--strip=\[\([^]]*\)\].*/\1/p')"
             return
             ;;
     esac
diff --git a/completions/ps b/completions/ps
index d32083ecea4..38732d183b2 100644
--- a/completions/ps
+++ b/completions/ps
@@ -50,7 +50,8 @@ _comp_cmd_ps()
         --format | ?(-)[Oo] | [^-]*[Oo])
             # TODO: This doesn't work well when there are multiple options for
             # the non-first item (similarly to useradd --groups and others).
-            _comp_delimited , -W "$("$1" L | awk '{ print $1 }')"
+            local labels=$("$1" L | awk '{ print $1 }')
+            _comp_delimited , -W '$labels'
             return
             ;;
     esac
diff --git a/completions/psql b/completions/psql
index 3426bff985f..206e34b7e66 100644
--- a/completions/psql
+++ b/completions/psql
@@ -4,15 +4,15 @@ _comp_cmd_psql__databases()
 {
     # -w was introduced in 8.4, https://launchpad.net/bugs/164772
     # "Access privileges" in output may contain linefeeds, hence the NF > 1
-    COMPREPLY=($(compgen -W "$(psql -XAtqwlF $'\t' 2>/dev/null |
-        awk 'NF > 1 { print $1 }')" -- "$cur"))
+    _comp_compgen_split -- "$(psql -XAtqwlF $'\t' 2>/dev/null |
+        awk 'NF > 1 { print $1 }')"
 }
 
 _comp_cmd_psql__users()
 {
     # -w was introduced in 8.4, https://launchpad.net/bugs/164772
-    COMPREPLY=($(compgen -W "$(psql -XAtqwc 'select usename from pg_user' \
-        template1 2>/dev/null)" -- "$cur"))
+    _comp_compgen_split -- "$(psql -XAtqwc 'select usename from pg_user' \
+        template1 2>/dev/null)"
     ((${#COMPREPLY[@]} == 0)) && _comp_compgen -- -u
 }
 
diff --git a/completions/pydoc b/completions/pydoc
index e7122a4488b..ce0fc60360e 100644
--- a/completions/pydoc
+++ b/completions/pydoc
@@ -31,8 +31,8 @@ _comp_cmd_pydoc()
 
     # Note that we don't do "pydoc modules" as it is known to hang on
     # some systems; _comp_xfunc_python_modules tends to work better and faster.
-    COMPREPLY+=($(compgen -W \
-        '$("$1" keywords topics | command sed -e /^Here/d)' -- "$cur"))
+    _comp_compgen -a split -- "$("$1" keywords topics |
+        command sed -e '/^Here/d')"
 
     _comp_compgen -a filedir py
 } &&
diff --git a/completions/python b/completions/python
index c7eaab720b3..d06f8f28677 100644
--- a/completions/python
+++ b/completions/python
@@ -16,9 +16,8 @@ _python_modules()
 
 _comp_cmd_python__modules()
 {
-    COMPREPLY+=($(compgen -W \
-        "$("$1" "${BASH_SOURCE[0]%/*}/../helpers/python" "$cur" \
-            2>/dev/null)" -- "$cur"))
+    _comp_compgen -a split -- "$("$1" \
+        "${BASH_SOURCE[0]%/*}/../helpers/python" "$cur" 2>/dev/null)"
 }
 
 # @since 2.12
@@ -63,10 +62,10 @@ _comp_cmd_python()
             return
             ;;
         -${noargopts}X)
-            COMPREPLY=($(compgen -W "$("$1" -h 2>&1 |
+            _comp_compgen_split -- "$("$1" -h 2>&1 |
                 awk '$1 == "-X" && $2 ~ /:$/ {
                     sub(":$","",$2); sub("=.*","=",$2); print $2
-                }')" -- "$cur"))
+                }')"
             [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
             return
             ;;
diff --git a/completions/qdbus b/completions/qdbus
index d53299a506b..0aa2c4f00fa 100644
--- a/completions/qdbus
+++ b/completions/qdbus
@@ -5,9 +5,10 @@ _comp_cmd_qdbus()
     local cur prev words cword comp_args
     _comp_initialize -- "$@" || return
 
-    [[ $cur ]] && unset -v "words[$((${#words[@]} - 1))]"
-    COMPREPLY=($(compgen -W '$(command "${words[@]}" 2>/dev/null | \
-        command sed "s/(.*)//")' -- "$cur"))
+    _comp_compgen_split -- "$(
+        [[ $cur ]] && unset -v "words[$((${#words[@]} - 1))]"
+        command "${words[@]}" 2>/dev/null | command sed 's/(.*)//'
+    )"
 } &&
     complete -F _comp_cmd_qdbus qdbus dcop
 
diff --git a/completions/qemu b/completions/qemu
index c6dd56f8575..8caf9a4880b 100644
--- a/completions/qemu
+++ b/completions/qemu
@@ -27,18 +27,17 @@ _comp_cmd_qemu()
             return
             ;;
         -soundhw)
-            COMPREPLY=($(compgen -W "$("$1" -soundhw help | awk \
-                '/^[[:lower:]]/ {print $1}') all" -- "$cur"))
+            _comp_compgen_split -- "$("$1" -soundhw help |
+                awk '/^[[:lower:]]/ {print $1}') all"
             return
             ;;
         -machine | -M)
-            COMPREPLY=($(compgen -W "$("$1" "$prev" help | awk \
-                '/^[[:lower:]]/ {print $1}')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" "$prev" help | awk \
+                '/^[[:lower:]]/ {print $1}')"
             return
             ;;
         -cpu)
-            COMPREPLY=($(compgen -W "$("$1" -cpu help | awk '{print $2}')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" -cpu help | awk '{print $2}')"
             return
             ;;
         -usbdevice)
@@ -81,8 +80,8 @@ _comp_cmd_qemu()
             return
             ;;
         -watchdog)
-            COMPREPLY=($(compgen -W "$("$1" -watchdog help 2>&1 |
-                awk '{print $1}')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" -watchdog help 2>&1 |
+                awk '{print $1}')"
             return
             ;;
         -watchdog-action)
diff --git a/completions/quota b/completions/quota
index afb7359710f..5772d47fa9b 100644
--- a/completions/quota
+++ b/completions/quota
@@ -31,8 +31,7 @@ _comp_cmd_quota__filesystems()
 {
     #  Only list filesystems starting with "/", otherwise we also get
     #+ "binfmt_misc", "proc", "tmpfs", ...
-    COMPREPLY=($(compgen -W "$(awk '/^\// {print $1}' /etc/mtab)" \
-        -- "$cur"))
+    _comp_compgen_split -- "$(awk '/^\// {print $1}' /etc/mtab)"
 }
 
 _comp_cmd_quota()
diff --git a/completions/reportbug b/completions/reportbug
index 98eb4e66dc0..a67b32f87c1 100644
--- a/completions/reportbug
+++ b/completions/reportbug
@@ -21,20 +21,19 @@ _comp_cmd_reportbug()
             return
             ;;
         --keyid | -${noargopts}K)
-            COMPREPLY=($(compgen -W '$(IFS=: ; \
-                gpg --list-keys --with-colons 2>/dev/null \
-                | while read -ra row ; do
-                    [[ "${row[0]}" == [ps]ub && ${row[11]} == *s* ]] && \
-                        printf "%s\n" "${row[4]}"
-                done)' -- "$cur"))
+            _comp_compgen_split -- "$(
+                IFS=:
+                gpg --list-keys --with-colons 2>/dev/null |
+                    while read -ra row; do
+                        [[ ${row[0]} == [ps]ub && ${row[11]} == *s* ]] &&
+                            printf '%s\n' "${row[4]}"
+                    done
+            )"
             return
             ;;
         --tag | --ui | --interface | --type | --bts | --severity | --mode | -${noargopts}[TutBS])
-            COMPREPLY=($(
-                compgen -W \
-                    '$("$1" "$prev" help 2>&1 | sed -ne "/^[[:space:]]/p")' \
-                    -- "$cur"
-            ))
+            _comp_compgen_split -- "$("$1" "$prev" help 2>&1 |
+                sed -ne '/^[[:space:]]/p')"
             return
             ;;
         --editor | --mua | --mbox-reader-cmd | -${noargopts}e)
@@ -43,8 +42,8 @@ _comp_cmd_reportbug()
             return
             ;;
         --from-buildd)
-            COMPREPLY=($(compgen -S "_" -W '$(apt-cache dumpavail | \
-                command grep "^Source: $cur" | sort -u | cut -f2 -d" ")'))
+            _comp_compgen_split -S "_" -- "$(apt-cache dumpavail |
+                command grep "^Source: $cur" | sort -u | cut -f2 -d' ')"
             return
             ;;
         --smtphost)
diff --git a/completions/rpcdebug b/completions/rpcdebug
index b71c429cbc5..8ff67b391fa 100644
--- a/completions/rpcdebug
+++ b/completions/rpcdebug
@@ -12,8 +12,8 @@ _comp_cmd_rpcdebug__flags()
     done
 
     if [[ $module ]]; then
-        COMPREPLY=($(compgen -W "$(rpcdebug -vh 2>&1 |
-            command sed -ne 's/^'"$module"'[[:space:]]\{1,\}//p')" -- "$cur"))
+        _comp_compgen_split -- "$(rpcdebug -vh 2>&1 |
+            command sed -ne 's/^'"$module"'[[:space:]]\{1,\}//p')"
     fi
 }
 
diff --git a/completions/rpm b/completions/rpm
index ef71d33fed8..79732bed718 100644
--- a/completions/rpm
+++ b/completions/rpm
@@ -13,12 +13,12 @@ _comp_cmd_rpm__installed_packages()
     if [[ -r /var/log/rpmpkgs &&
         /var/log/rpmpkgs -nt /var/lib/rpm/Packages ]]; then
         # using RHL 7.2 or later - this is quicker than querying the DB
-        COMPREPLY=($(compgen -W "$(command sed -ne \
+        _comp_compgen_split -- "$(command sed -ne \
             's|^\([^[:space:]]\{1,\}\)-[^[:space:]-]\{1,\}-[^[:space:]-]\{1,\}\.rpm$|\1|p' \
-            /var/log/rpmpkgs)" -- "$cur"))
+            /var/log/rpmpkgs)"
     elif type rpmqpack &>/dev/null; then
         # SUSE's rpmqpack is faster than rpm -qa
-        COMPREPLY=($(compgen -W '$(rpmqpack)' -- "$cur"))
+        _comp_compgen_split -- "$(rpmqpack)"
     else
         COMPREPLY=($("${1:-rpm}" -qa --nodigest --nosignature \
             --queryformat='%{NAME} ' "$cur*" 2>/dev/null))
@@ -31,24 +31,22 @@ _comp_deprecate_func 2.12 _rpm_installed_packages \
 _comp_cmd_rpm__groups()
 {
     local IFS=$'\n'
-    COMPREPLY=($(compgen -W "$("${1:-rpm}" -qa --nodigest --nosignature \
-        --queryformat='%{GROUP}\n' 2>/dev/null)" -- "$cur"))
+    _comp_compgen_split -- "$("${1:-rpm}" -qa --nodigest --nosignature \
+        --queryformat='%{GROUP}\n' 2>/dev/null)"
 }
 
 _comp_cmd_rpm__macros()
 {
     # get a list of macros
-    COMPREPLY=($(compgen -W "$("${1:-rpm}" --showrc | command sed -ne \
-        's/^-\{0,1\}[0-9]\{1,\}[:=][[:space:]]\{1,\}\([^[:space:](]\{3,\}\).*/%\1/p')" \
-        -- "$cur"))
+    _comp_compgen_split -- "$("${1:-rpm}" --showrc | command sed -ne \
+        's/^-\{0,1\}[0-9]\{1,\}[:=][[:space:]]\{1,\}\([^[:space:](]\{3,\}\).*/%\1/p')"
 }
 
 # shellcheck disable=SC2120
 _comp_cmd_rpm__buildarchs()
 {
-    COMPREPLY=($(compgen -W "$("${1:-rpm}" --showrc | command sed -ne \
-        's/^\s*compatible\s\s*build\s\s*archs\s*:\s*\(.*\)/\1/ p')" \
-        -- "$cur"))
+    _comp_compgen_split -- "$("${1:-rpm}" --showrc | command sed -ne \
+        's/^\s*compatible\s\s*build\s\s*archs\s*:\s*\(.*\)/\1/ p')"
 }
 
 # shellcheck disable=SC2120
@@ -120,9 +118,9 @@ _comp_cmd_rpm()
                     *suggests) fmt="%{SUGGESTNAME}" ;;
                     *supplements) fmt="%{SUPPLEMENTNAME}" ;;
                 esac
-                COMPREPLY=($(compgen -W "$("$1" -qa --nodigest --nosignature \
+                _comp_compgen_split -- "$("$1" -qa --nodigest --nosignature \
                     --queryformat=\"$fmt\\n\" 2>/dev/null |
-                    command grep -vF '(none)')" -- "$cur"))
+                    command grep -vF '(none)')"
             fi
             return
             ;;
@@ -282,8 +280,8 @@ _comp_cmd_rpmbuild()
             local cfgdir
             _comp_cmd_rpm__configdir
             if [[ $cfgdir ]]; then
-                COMPREPLY=($(compgen -W "$(command ls "$cfgdir" 2>/dev/null |
-                    command sed -ne 's/^brp-//p')" -- "$cur"))
+                _comp_compgen_split -- "$(command ls "$cfgdir" 2>/dev/null |
+                    command sed -ne 's/^brp-//p')"
             fi
             ;;
         --define | --with | --without | -${noargopts}D)
diff --git a/completions/sbopkg b/completions/sbopkg
index 6b1acb29080..6917ec7b0a1 100644
--- a/completions/sbopkg
+++ b/completions/sbopkg
@@ -24,8 +24,7 @@ _comp_cmd_sbopkg()
             return
             ;;
         -V)
-            COMPREPLY=($(compgen -W "?
-                $(sbopkg -V '?' 2>&1 | cut -s -f1)" -- "$cur"))
+            _comp_compgen_split -- "? $(sbopkg -V '?' 2>&1 | cut -s -f1)"
             return
             ;;
         -i | -b) ;;
diff --git a/completions/scrub b/completions/scrub
index 1622bad89cf..3906742cf81 100644
--- a/completions/scrub
+++ b/completions/scrub
@@ -13,9 +13,8 @@ _comp_cmd_scrub()
             return
             ;;
         --pattern | -${noargopts}p)
-            COMPREPLY=($(compgen -W '$("$1" --help 2>&1 |
-                awk "/^Available/{flag=1;next}/^ /&&flag{print \$1}")' \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" --help 2>&1 |
+                awk '/^Available/{flag=1;next}/^ /&&flag{print $1}')"
             return
             ;;
         --freespace | -${noargopts}X)
diff --git a/completions/sitecopy b/completions/sitecopy
index 5f7198226e7..87e877556a9 100644
--- a/completions/sitecopy
+++ b/completions/sitecopy
@@ -43,8 +43,8 @@ _comp_cmd_sitecopy()
     esac
 
     if [[ -r ~/.sitecopyrc ]]; then
-        COMPREPLY=($(compgen -W "$("$1" -v |
-            command sed -n '/^Site:/s/Site: //p')" -- "$cur"))
+        _comp_compgen_split -- "$("$1" -v |
+            command sed -n '/^Site:/s/Site: //p')"
     fi
 } &&
     complete -F _comp_cmd_sitecopy -o default sitecopy
diff --git a/completions/smbclient b/completions/smbclient
index 01c7483f304..bd2deebb576 100644
--- a/completions/smbclient
+++ b/completions/smbclient
@@ -8,17 +8,15 @@ _comp_cmd_smbclient__resolve_order()
 _comp_cmd_smbclient__domains()
 {
     if [[ ${BASH_COMPLETION_CMD_SMBTREE_SCAN-${COMP_SAMBA_SCAN-}} ]]; then
-        COMPREPLY=($(compgen -W '$(smbtree -N -D)' -- "$cur"))
+        _comp_compgen_split -- "$(smbtree -N -D)"
     fi
 }
 
 _comp_cmd_smbclient__hosts()
 {
     if [[ ${BASH_COMPLETION_CMD_SMBTREE_SCAN-${COMP_SAMBA_SCAN-}} ]]; then
-        COMPREPLY=($(compgen -W "$(
-            smbtree -N -S |
-                command sed -ne 's/^[[:space:]]*\\\\*\([^[:space:]]*\).*/\1/p'
-        )" -- "$cur"))
+        _comp_compgen_split -- "$(smbtree -N -S |
+            command sed -ne 's/^[[:space:]]*\\\\*\([^[:space:]]*\).*/\1/p')"
     fi
 }
 
diff --git a/completions/ss b/completions/ss
index 08ddf5edc0a..e383fe57a8a 100644
--- a/completions/ss
+++ b/completions/ss
@@ -16,8 +16,9 @@ _comp_cmd_ss()
             return
             ;;
         --query | -${noargopts}A)
-            _comp_delimited , -W "$("$1" --help |
-                command sed -e 's/|/ /g' -ne 's/.*QUERY := {\([^}]*\)}.*/\1/p')"
+            local queries=$("$1" --help |
+                command sed -e 's/|/ /g' -ne 's/.*QUERY := {\([^}]*\)}.*/\1/p')
+            _comp_delimited , -W '$queries'
             return
             ;;
         --diag | --filter | -${noargopts}[DF])
diff --git a/completions/ssh b/completions/ssh
index 6f10346643c..2000c4d379d 100644
--- a/completions/ssh
+++ b/completions/ssh
@@ -145,7 +145,7 @@ _comp_cmd_ssh__suboption()
             _comp_compgen_filedir
             ;;
         casignaturealgorithms)
-            COMPREPLY=($(compgen -W '$(_comp_cmd_ssh__query "$1" sig)' -- "$cur"))
+            _comp_compgen_split -- "$(_comp_cmd_ssh__query "$1" sig)"
             ;;
         cipher)
             _comp_compgen -- -W 'blowfish des 3des'
@@ -167,10 +167,10 @@ _comp_cmd_ssh__suboption()
                 cs{0..7} ef lowdelay throughput reliability'
             ;;
         hostbasedkeytypes | hostkeyalgorithms)
-            COMPREPLY=($(compgen -W '$(_comp_cmd_ssh__query "$1" key)' -- "$cur"))
+            _comp_compgen_split -- "$(_comp_cmd_ssh__query "$1" key)"
             ;;
         kexalgorithms)
-            COMPREPLY=($(compgen -W '$(_comp_cmd_ssh__query "$1" kex)' -- "$cur"))
+            _comp_compgen_split -- "$(_comp_cmd_ssh__query "$1" kex)"
             ;;
         loglevel)
             _comp_compgen -- -W 'QUIET FATAL ERROR INFO VERBOSE DEBUG{,1,2,3}'
@@ -199,7 +199,7 @@ _comp_cmd_ssh__suboption()
             _comp_compgen -- -c
             ;;
         pubkeyacceptedalgorithms | pubkeyacceptedkeytypes)
-            COMPREPLY=($(compgen -W '$(_comp_cmd_ssh__query "$1" key)' -- "$cur"))
+            _comp_compgen_split -- "$(_comp_cmd_ssh__query "$1" key)"
             ;;
         requesttty)
             _comp_compgen -- -W 'no yes force auto'
diff --git a/completions/strings b/completions/strings
index 453215e6aec..45f0e6064c3 100644
--- a/completions/strings
+++ b/completions/strings
@@ -17,18 +17,13 @@ _comp_cmd_strings()
             return
             ;;
         --target | -${noargopts}T)
-            COMPREPLY=($(compgen -W '$(LC_ALL=C "$1" --help 2>/dev/null | \
-                command sed -ne "s/: supported targets: \(.*\)/\1/p")' \
-                -- "$cur"))
+            _comp_compgen_split -- "$(LC_ALL=C "$1" --help 2>/dev/null |
+                command sed -ne 's/: supported targets: \(.*\)/\1/p')"
             return
             ;;
         --encoding | -${noargopts}e)
-            COMPREPLY=($(
-                IFS=, compgen -W \
-                    '$(LC_ALL=C "$1" --help 2>/dev/null | \
-                         command sed -ne "s/.*--encoding={\([^}]*\)}.*/\1/p")' \
-                    -- "$cur"
-            ))
+            _comp_compgen_split -F , -- "$(LC_ALL=C "$1" --help 2>/dev/null |
+                command sed -ne 's/.*--encoding={\([^}]*\)}.*/\1/p')"
             return
             ;;
     esac
diff --git a/completions/svk b/completions/svk
index 278c029a4f8..4d81c158aa3 100644
--- a/completions/svk
+++ b/completions/svk
@@ -188,8 +188,8 @@ _comp_cmd_svk()
                         --regenerate --up --update --apply --rm --delete'
                     ;;
                 sync)
-                    COMPREPLY=($(compgen -W "$("$1" mirror --list \
-                        2>/dev/null | awk '/^\//{print $1}')" -- "$cur"))
+                    _comp_compgen_split -- "$("$1" mirror --list \
+                        2>/dev/null | awk '/^\//{print $1}')"
                     ;;
                 co | checkout | push | pull)
                     if [[ $cur == //*/* ]]; then
@@ -197,8 +197,8 @@ _comp_cmd_svk()
                     else
                         path=//
                     fi
-                    COMPREPLY=($(compgen -W "$("$1" list "$path" 2>/dev/null |
-                        command sed -e 's|\(.*\)|'"$path"'\1|')" -- "$cur"))
+                    _comp_compgen_split -- "$("$1" list "$path" 2>/dev/null |
+                        command sed -e 's|\(.*\)|'"$path"'\1|')"
                     ;;
                 *)
                     _comp_compgen_filedir
diff --git a/completions/synclient b/completions/synclient
index 1452d345ca6..609677df24f 100644
--- a/completions/synclient
+++ b/completions/synclient
@@ -14,8 +14,8 @@ _comp_cmd_synclient()
     if [[ $cur == -* ]]; then
         _comp_compgen_usage
     elif [[ $cur != *=?* ]]; then
-        COMPREPLY=($(compgen -S = -W '$("$1" -l 2>/dev/null | \
-            awk "/^[ \t]/ { print \$1 }")' -- "$cur"))
+        _comp_compgen_split -S = -- "$("$1" -l 2>/dev/null |
+            awk '/^[ \t]/ { print $1 }')"
         compopt -o nospace
     fi
 } &&
diff --git a/completions/sysbench b/completions/sysbench
index 8d117c11e44..a6a45a71e72 100644
--- a/completions/sysbench
+++ b/completions/sysbench
@@ -74,9 +74,9 @@ _comp_cmd_sysbench()
             return
             ;;
         --db-driver)
-            COMPREPLY=($(compgen -W "$("$1" --test=oltp help 2>/dev/null |
+            _comp_compgen_split -- "$("$1" --test=oltp help 2>/dev/null |
                 command sed -e '/^.*database drivers:/,/^$/!d' \
-                    -ne 's/^  *\([^ ]*\) .*/\1/p')" -- "$cur"))
+                    -ne 's/^  *\([^ ]*\) .*/\1/p')"
             return
             ;;
         --db-ps-mode)
diff --git a/completions/sysctl b/completions/sysctl
index e0024e26b86..4062a7fc1da 100644
--- a/completions/sysctl
+++ b/completions/sysctl
@@ -22,8 +22,9 @@ _comp_cmd_sysctl()
     else
         local suffix=
         [[ $prev == -w ]] && suffix="="
-        COMPREPLY=($(compgen -S "$suffix" -W \
-            "$(PATH="$PATH:/sbin" $1 -N -a 2>/dev/null)" -- "$cur"))
+        _comp_compgen_split -S "$suffix" -- "$(
+            PATH="$PATH:/sbin" $1 -N -a 2>/dev/null
+        )"
         [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
     fi
 } &&
diff --git a/completions/tar b/completions/tar
index e64aa2bcbca..7887f92a763 100644
--- a/completions/tar
+++ b/completions/tar
@@ -431,13 +431,12 @@ _comp_cmd_tar__try_list_archive()
         fi
     done
     if [[ $tarball ]]; then
-        local IFS=$'\n'
-        COMPREPLY=($(compgen -o filenames -W "$(
+        _comp_compgen -c "$(printf %q "$cur")" split -lo filenames -- "$(
             $tarbin $untar "$tarball" 2>/dev/null |
                 while read -r line; do
-                    printf "%q\n" "$(printf %q"\n" "$line")"
+                    printf "%q\n" "$line"
                 done
-        )" -- "$(printf %q "$cur")"))
+        )"
         return 0
     fi
 }
@@ -599,7 +598,7 @@ _comp_cmd_tar__gnu()
                 break
                 ;;
             --warning)
-                COMPREPLY=($(compgen -W "$(__gtar_parse_warnings)" -- "$cur"))
+                _comp_compgen_split -- "$(__gtar_parse_warnings)"
                 break
                 ;;
             --*)
diff --git a/completions/tshark b/completions/tshark
index 9390de4be51..37229b71dde 100644
--- a/completions/tshark
+++ b/completions/tshark
@@ -36,8 +36,7 @@ _comp_cmd_tshark()
             return
             ;;
         -*i)
-            COMPREPLY=($(compgen -W \
-                "$("$1" -D 2>/dev/null | awk '{print $2}')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" -D 2>/dev/null | awk '{print $2}')"
             return
             ;;
         -*y)
@@ -49,8 +48,8 @@ _comp_cmd_tshark()
                 fi
             done
             # shellcheck disable=SC2086
-            COMPREPLY=($(compgen -W "$("$1" $opts -L 2>/dev/null |
-                awk '/^  / { print $1 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" $opts -L 2>/dev/null |
+                awk '/^  / { print $1 }')"
             return
             ;;
         -*[ab])
@@ -69,8 +68,7 @@ _comp_cmd_tshark()
             return
             ;;
         -*F)
-            COMPREPLY=($(compgen -W "$("$1" -F 2>&1 |
-                awk '/^  / { print $1 }')" -- "$cur"))
+            _comp_compgen_split -- "$("$1" -F 2>&1 | awk '/^  / { print $1 }')"
             return
             ;;
         -*O)
@@ -110,10 +108,10 @@ _comp_cmd_tshark()
             return
             ;;
         -*G)
-            COMPREPLY=($(compgen -W "$("$1" -G \? 2>/dev/null |
-                awk '/^[ \t]*-G / \
-                    { sub("^[[]","",$2); sub("[]]$","",$2); print $2 }')" \
-                -- "$cur"))
+            _comp_compgen_split -- "$("$1" -G \? 2>/dev/null |
+                awk '/^[ \t]*-G / {
+                    sub("^[[]","",$2); sub("[]]$","",$2); print $2
+                }')"
             return
             ;;
 
diff --git a/completions/update-alternatives b/completions/update-alternatives
index a98311f075d..07e549779dd 100644
--- a/completions/update-alternatives
+++ b/completions/update-alternatives
@@ -13,7 +13,7 @@ _comp_cmd_update_alternatives__installed()
             break
         fi
     done
-    COMPREPLY=($(compgen -W '$(command ls $admindir)' -- "$cur"))
+    _comp_compgen_split -- "$(command ls "$admindir")"
 }
 
 _comp_cmd_update_alternatives()
diff --git a/completions/valgrind b/completions/valgrind
index 7fafaacfe61..068a0fe6f45 100644
--- a/completions/valgrind
+++ b/completions/valgrind
@@ -30,12 +30,14 @@ _comp_cmd_valgrind()
             # we want to grab memcheck.
             local -a files
             _comp_expand_glob files '/usr{,/local}/lib{,64,exec}{/*-linux-gnu,}/valgrind/*'
-            ((${#files[@]})) &&
-                COMPREPLY=($(compgen -W '$(
+            if ((${#files[@]})); then
+                _comp_compgen_split -- "$(
                     for f in "${files[@]}"; do
                         [[ $f != *.so && -x $f && $f =~ ^.*/(.*)-[^-]+-[^-]+ ]] &&
-                            printf "%s\n" "${BASH_REMATCH[1]}"
-                    done)' -- "$cur"))
+                            printf '%s\n' "${BASH_REMATCH[1]}"
+                    done
+                )"
+            fi
             return
             ;;
         --sim-hints)
diff --git a/completions/wget b/completions/wget
index 7b2a2ba59fe..43c85f980b0 100644
--- a/completions/wget
+++ b/completions/wget
@@ -122,9 +122,9 @@ _comp_cmd_wget()
             return
             ;;
         --user | --http-user | --proxy-user | --ftp-user)
-            COMPREPLY=($(compgen -W "$(command sed -n \
+            _comp_compgen_split -- "$(command sed -n \
                 '/^login/s/^[[:blank:]]*login[[:blank:]]//p' ~/.netrc \
-                2>/dev/null)" -- "$cur"))
+                2>/dev/null)"
             return
             ;;
         --header)
diff --git a/completions/wodim b/completions/wodim
index 71503a7d07a..ffe3949b4df 100644
--- a/completions/wodim
+++ b/completions/wodim
@@ -43,8 +43,8 @@ _comp_cmd_wodim()
                 fi
                 ;;
             driver)
-                COMPREPLY=($(compgen -W "$("$1" driver=help 2>&1 |
-                    awk 'NR > 1 { print $1 }') help" -- "$cur"))
+                _comp_compgen_split -- "$("$1" driver=help 2>&1 |
+                    awk 'NR > 1 { print $1 }') help"
                 ;;
             minbuf)
                 _comp_compgen -- -W '{25..95}'
diff --git a/completions/wtf b/completions/wtf
index 4cd35f61542..155185e30d9 100644
--- a/completions/wtf
+++ b/completions/wtf
@@ -37,8 +37,8 @@ _comp_cmd_wtf()
         [[ $has_db ]] || return
     fi
 
-    COMPREPLY=($(compgen -W "$(cut -f 1 -s "$db"* 2>/dev/null) $addf" \
-        -- "${cur^^}"))
+    _comp_compgen -c "${cur^^}" split \
+        -- "$(cut -f 1 -s "$db"* 2>/dev/null) $addf"
 } &&
     complete -F _comp_cmd_wtf wtf
 
diff --git a/completions/xdg-settings b/completions/xdg-settings
index f368fb263d2..2e8f41b2292 100644
--- a/completions/xdg-settings
+++ b/completions/xdg-settings
@@ -21,8 +21,7 @@ _comp_cmd_xdg_settings()
     if ((args == 1)); then
         _comp_compgen -- -W "get check set"
     elif ((args == 2)); then
-        COMPREPLY=($(compgen -W \
-            '$("$1" --list | awk "!/^Known/ { print \$1 }")' -- "$cur"))
+        _comp_compgen_split -- "$("$1" --list | awk '!/^Known/ { print $1 }')"
     fi
 } &&
     complete -F _comp_cmd_xdg_settings xdg-settings
diff --git a/completions/xfreerdp b/completions/xfreerdp
index 3c2e6b4d3ca..71b276e52ee 100644
--- a/completions/xfreerdp
+++ b/completions/xfreerdp
@@ -7,8 +7,8 @@ _comp_cmd_xfreerdp()
 
     case $prev in
         -k)
-            COMPREPLY=($(compgen -W '$("$1" --kbd-list |
-                awk "/^0x/ { print \$1 }")' -- "$cur"))
+            _comp_compgen_split -- "$("$1" --kbd-list |
+                awk '/^0x/ { print $1 }')"
             return
             ;;
         -a)
@@ -30,8 +30,8 @@ _comp_cmd_xfreerdp()
 
     case $cur in
         /kbd:*)
-            COMPREPLY=($(compgen -W '$("$1" /kbd-list |
-                awk "/^0x/ { print \$1 }")' -- "${cur#/kbd:}"))
+            _comp_compgen -c "${cur#/kbd:}" split -- "$("$1" /kbd-list |
+                awk '/^0x/ { print $1 }')"
             return
             ;;
         /bpp:*)
@@ -45,17 +45,17 @@ _comp_cmd_xfreerdp()
 
     if [[ $cur == /* ]]; then
         _comp_compgen_filedir rdp
-        COMPREPLY+=($(compgen -W '$("$1" --help |
-            awk "\$1 ~ /^\\// && \$1 !~ /^.(flag\$|option:)/ { sub(\":.*\",\":\",\$1); print \$1 }")' \
-            -- "$cur"))
+        _comp_compgen -a split -- "$(
+            "$1" --help | awk '$1 ~ /^\// && $1 !~ /^.(flag$|option:)/ {
+                sub(":.*",":",$1); print $1 }'
+        )"
         [[ ${COMPREPLY-} == *: ]] && compopt -o nospace
     elif [[ $cur == [+-]* ]]; then
         local char=${cur:0:1}
         local help="$("$1" --help)"
         if [[ $help == */help* ]]; then # new/slash syntax
-            COMPREPLY=($(compgen -W '$(awk "
-                \$1 ~ /^[+-]/ && \$1 !~ /^.toggle\$/ { sub(\"^.\",\"$char\",\$1); print \$1 }
-            " <<<"$help")' -- "$cur"))
+            _comp_compgen_split -- "$(awk '$1 ~ /^[+-]/ && $1 !~ /^.toggle$/ {
+                    sub("^.","'"$char"'",$1); print $1 }' <<<"$help")"
         else # old/dash syntax
             _comp_compgen -R help - <<<"$help"
             ((${#COMPREPLY[@]})) &&
@@ -63,8 +63,9 @@ _comp_cmd_xfreerdp()
         fi
     else
         _comp_compgen_filedir rdp
-        COMPREPLY+=($(compgen -W "$(awk '{print $1}' ~/.freerdp/known_hosts \
-            2>/dev/null)" -- "$cur"))
+        _comp_compgen -a split -- "$(
+            awk '{print $1}' ~/.freerdp/known_hosts 2>/dev/null
+        )"
     fi
 
 } &&
diff --git a/completions/xsltproc b/completions/xsltproc
index 3f06c8e26c5..5d75596cd37 100644
--- a/completions/xsltproc
+++ b/completions/xsltproc
@@ -16,8 +16,8 @@ _comp_cmd_xsltproc()
             ;;
         --encoding)
             # some aliases removed
-            COMPREPLY=($(compgen -X '@(UTF[1378]|8859|ISO[0-9_])*' \
-                -W "$(iconv -l | command sed -e 's/\/.*//')" -- "$cur"))
+            local encodings=$(iconv -l | command sed -e 's/\/.*//')
+            _comp_compgen -- -X '@(UTF[1378]|8859|ISO[0-9_])*' -W '$encodings'
             return
             ;;
         --param | --stringparam)
diff --git a/completions/ypmatch b/completions/ypmatch
index 13d266e5421..db5a233e0c4 100644
--- a/completions/ypmatch
+++ b/completions/ypmatch
@@ -12,13 +12,10 @@ _comp_cmd_ypmatch()
 
     if [[ $cmd == ypmatch && $cword -eq 1 && ${#words[@]} -eq 3 ]]; then
         map=${words[2]}
-        COMPREPLY=($(compgen -W '$(ypcat "$map" 2>/dev/null | \
-            cut -d':' -f 1)' -- "$cur"))
+        _comp_compgen_split -- "$(ypcat "$map" 2>/dev/null | cut -d':' -f 1)"
     else
         [[ $cmd == ypmatch && $cword -ne 2 ]] && return
-        COMPREPLY=($(compgen -W \
-            '$(printf "%s\n" $(ypcat -x 2>/dev/null | \
-               cut -d"\"" -f 2))' -- "$cur"))
+        _comp_compgen_split -- "$(ypcat -x 2>/dev/null | cut -d'"' -f 2)"
     fi
 } &&
     complete -F _comp_cmd_ypmatch ypmatch ypcat
diff --git a/test/t/unit/test_unit_compgen_split.py b/test/t/unit/test_unit_compgen_split.py
new file mode 100644
index 00000000000..935ea2a19c2
--- /dev/null
+++ b/test/t/unit/test_unit_compgen_split.py
@@ -0,0 +1,102 @@
+import pytest
+
+from conftest import assert_bash_exec
+
+
+@pytest.mark.bashcomp(cmd=None)
+class TestUtilCompgenSplit:
+    @pytest.fixture
+    def functions(self, bash):
+        assert_bash_exec(
+            bash,
+            "_comp__test_dump() { ((${#arr[@]})) && printf '<%s>' \"${arr[@]}\"; echo; }",
+        )
+        assert_bash_exec(
+            bash,
+            '_comp__test_compgen() { local -a arr=(00); _comp_compgen -v arr "$@"; _comp__test_dump; }',
+        )
+
+        assert_bash_exec(
+            bash,
+            "_comp__test_cmd1() { echo foo bar; echo baz; }",
+        )
+        assert_bash_exec(
+            bash,
+            '_comp__test_attack() { echo "\\$(echo should_not_run >&2)"; }',
+        )
+
+    def test_1_basic(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo><bar><baz>"
+
+    def test_2_attack(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -- "$(_comp__test_attack)"',
+            want_output=True,
+        )
+        assert output.strip() == "<$(echo><should_not_run><>&2)>"
+
+    def test_3_sep1(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -l -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo bar><baz>"
+
+    def test_3_sep2(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            "_comp__test_compgen split -F $'b\\n' -- \"$(_comp__test_cmd1)\"",
+            want_output=True,
+        )
+        assert output.strip() == "<foo ><ar><az>"
+
+    def test_4_optionX(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -X bar -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo><baz>"
+
+    def test_4_optionS(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -S .txt -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<foo.txt><bar.txt><baz.txt>"
+
+    def test_4_optionP(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -P /tmp/ -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "</tmp/foo></tmp/bar></tmp/baz>"
+
+    def test_4_optionPS(self, bash, functions):
+        output = assert_bash_exec(
+            bash,
+            '_comp__test_compgen split -P [ -S ] -- "$(_comp__test_cmd1)"',
+            want_output=True,
+        )
+        assert output.strip() == "<[foo]><[bar]><[baz]>"
+
+    def test_5_empty(self, bash, functions):
+        output = assert_bash_exec(
+            bash, '_comp__test_compgen split -- ""', want_output=True
+        )
+        assert output.strip() == ""
+
+    def test_5_empty2(self, bash, functions):
+        output = assert_bash_exec(
+            bash, '_comp__test_compgen split -- " "', want_output=True
+        )
+        assert output.strip() == ""