From da4a0e76fbd2a0b7a2ecf14846c402e1b2aba4f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Josef=20=C5=A0pa=C4=8Dek?= <mspacek@redhat.com>
Date: Thu, 5 Jun 2025 16:28:09 +0200
Subject: [PATCH] Add resolving of $PROGRAM_NAME from /dev/fd/<number>

There are situations when $PROGRAM_NAME is something /dev/fd/<number>
1) example like sudo /usr/local/bin/<tool> with checksum verification
(GH#23351)
2) example with pipe: perl <( echo '#!perl -DA'; echo 'print "$0\n"');
---
 AUTHORS |  1 +
 perl.c  | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/AUTHORS b/AUTHORS
index 6b244913fa18..186ed2093187 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -988,6 +988,7 @@ Michael Somos                  <somos@grail.cba.csuohio.edu>
 Michael Stevens                <mstevens@etla.org>
 Michael van Elst               <mlelstv@serpens.de>
 Michael Witten                 <mfwitten@gmail.com>
+Michal Josef Špaček            <mspacek@redhat.com>
 Michele Sardo
 Michiel Beijen                 <mb@x14.nl>
 Mik Firestone                  <fireston@lexmark.com>
diff --git a/perl.c b/perl.c
index 5c87e47ee294..e7dab8376b7f 100644
--- a/perl.c
+++ b/perl.c
@@ -4227,6 +4227,19 @@ S_open_script(pTHX_ const char *scriptname, bool dosearch, bool *suidscript)
                 Safefree(PL_origfilename);
                 PL_origfilename = (char *)scriptname;
             }
+            else {
+                char proc_fd_path[64];
+                snprintf(proc_fd_path, sizeof(proc_fd_path), "/proc/self/fd/%d", fdscript);
+                char target_path[MAXPATHLEN];
+                SSize_t len = readlink(proc_fd_path, target_path, sizeof(target_path) - 1);
+                if (len != -1) {
+                    Stat_t statbuf;
+                    target_path[len] = '\0';
+                    if (PerlLIO_stat(target_path, &statbuf) == 0 && S_ISREG(statbuf.st_mode)) {
+                        scriptname = PL_origfilename = find_script(target_path, dosearch, NULL, 1);
+                    }
+                }
+            }
         }
     }