system returns -1 even though command executed successfully

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

why does perl system function returns -1, and $! has 'no child process' even though the command execution goes fine ( redirected result it is properly available - which ensures command executed correctly )

And just before executing $SIG{'CHLD'} is set to DEFAULT. What can be the reason for the -1 returned? Command executed is date command.

Comment on system returns -1 even though command executed successfully

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Re: system returns -1 even though command executed successfully by Eliya (Vicar) on Jan 10, 2012 at 16:20 UTC
Here's an arbitrary example that (on my system) behaves as you describe: `$SIG{CHLD} = sub { wait }; system "date && foo 2>/dev/null"; print "ret: $?\n"; print "err: $!\n"; _END__ Tue Jan 10 17:19:35 CET 2012 ret: -1 err: No child processes` [download] The `-1` is because of the failed foo. and the "no child processes" (ECHILD) is because of the SIGCHLD reaper getting called without there being an unreaped child process (`system()` itself has already reaped it). As you haven't shown what exactly you're doing, I'll leave it up to you to check for possible similarities with your code...	[reply] [d/l] [select]
Re: system returns -1 even though command executed successfully by Anonymous Monk on Jan 10, 2012 at 14:11 UTC
why does perl ... {{{ no code shown }} :) Maybe your copy of perl or date hates you? Mine doesn't return -1 when nothing is wrong `$ perl -le " print system qw/ date / " Tue Jan 10 06:14:05 PST 2012 0` [download]	[reply] [d/l]