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 <t.lampre...@proxmox.com>
---
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
_______________________________________________
pve-devel mailing list
pve-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
