I am executing shell command using perl using open 3
local ( *HANDLE_IN, *HANDLE_OUT, *HANDLE_ERR );
my $pid = open3( *HANDLE_IN, *HANDLE_OUT, *HANDLE_ERR, @cmd_args );
where @cmd_args = my shell command
My shell returns below exit codes
0: command executed successfully
>0: error in executing the command
How can i capture the exit code from shell in my perl?
It's easy, just look at the good old perldoc:
$pid = open3(\*CHLD_IN, \*CHLD_OUT, \*CHLD_ERR,
'some cmd and args', 'optarg', ...);
my($wtr, $rdr, $err);
use Symbol 'gensym'; $err = gensym;
$pid = open3($wtr, $rdr, $err,
'some cmd and args', 'optarg', ...);
waitpid( $pid, 0 );
my $child_exit_status = $? >> 8;
$child_exit_status then contains the status of the program executed.
Another method to use is ${^CHILD_ERROR_NATIVE} which I'm using especially when executing external commands via backticks:
my $fancyresult = `ls -lsahR /`;
if (${^CHILD_ERROR_NATIVE} != 0) {
...
$? for backticks too.
You need to eventually reap the child using wait or waitpid. When you do, $? will be set as follows.
waitpid($pid, 0);
die "Can't waitpid: $!" if $? < 0;
die "Child killed by signal ".( $? & 0x7F ) if $? & 0x7F;
die "Child returned error ".( $? >> 8 ) if $? >> 8;
print "Child ran successfully!\n"; # if $? == 0
