From 06d1efe8235ca11738373e0215ac926949a3cb2e Mon Sep 17 00:00:00 2001 From: Thomas Lamprecht Date: Mon, 26 Feb 2024 14:34:09 +0100 Subject: [PATCH 1/1] run command: avoid using 1 as special value In Perl, the last expression of a block (e.g. of a method, eval) gets returned if there's no explicit return statement. Quite often that is truthy, i.e., 1. As that was chosen as the special value for the CMD_FINISHED flag it had quite a few false positives, causing weird effects and installation failure. Reserve that overly problematic value and chose 2 as new CMD_FINISHED value, albeit it could be better to signal this even more explicitly, like with a structured hash reference, but for now this is a good stop gap. Fixes: 23c5fbe ("sys: command: allow terminating the process early from log subroutine") Signed-off-by: Thomas Lamprecht --- Proxmox/Sys/Command.pm | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/Proxmox/Sys/Command.pm b/Proxmox/Sys/Command.pm index cb5fe76..ac505c4 100644 --- a/Proxmox/Sys/Command.pm +++ b/Proxmox/Sys/Command.pm @@ -17,7 +17,10 @@ use Proxmox::UI; use base qw(Exporter); our @EXPORT_OK = qw(run_command syscmd CMD_FINISHED); -use constant CMD_FINISHED => 1; +use constant { + CMD_RESERVED => 1<<0, # reserve 1 as it's often the default return value of closures + CMD_FINISHED => 1<<1, +}; my sub shellquote { my $str = shift; @@ -78,8 +81,9 @@ sub syscmd { # # Arguments: # * $cmd - The command to run, either a single string or array with individual arguments -# * $func - Logging subroutine to call, receives both stdout and stderr. Might return CMD_FINISHED -# to exit early and ignore the rest of the process output. +# * $func - Logging subroutine to call, receives both stdout and stderr. +# Can return CMD_FINISHED to exit early and ignore the rest of the process output. +# Should use an explicit `return;` to avoid misinterpretation of return value. # * $input - Stdin contents for the spawned subprocess # * $noout - Whether to append any process output to the return value # * $noprint - Whether to print any process output to the parents stdout -- 2.39.2