Re: Exit codes from forking children

I bet the child gets killed by a SIGPIPE (13) in the gzip case.

See system for how to properly interpret $? to also catch such errors (the signal number is in the lower byte which you're just "shifting out" by unconditionally doing $? >> 8).

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Re^2: Exit codes from forking children by ikegami (Patriarch) on Dec 04, 2009 at 00:05 UTC
Good call. defined( my $pid = open(CMD, '-\|') ) or die("Can't fork: $!\n"); if ($pid == 0) { close(STDERR); open(STDERR, ">&STDOUT") or print "Unable to reopen STDOUT, errors may be lost: $!"; exec('/bin/tar', 'czf', '/nonexistent/test.tar.gz', '.') or die("Unable to exec: $!") } local $/ = undef; my $output .= <CMD>; close(CMD); if ($? == -1) { die("Can't close pipe: $!\n"); } elsif ($? & 127) { die("tar died from signal ", ($? & 127), "\n"); } elsif ($? >> 8) { die("tar exited with error ", ($? >> 8), "\n"); } print $output; [download] `tar died from signal 13` [download]	[reply] [d/l] [select]

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Re^2: Exit codes from forking children
by ikegami (Patriarch) on Dec 04, 2009 at 00:05 UTC

defined( my $pid = open(CMD, '-|') )
    or die("Can't fork: $!\n");

if ($pid == 0) {
    close(STDERR);
    open(STDERR, ">&STDOUT")
        or print "Unable to reopen STDOUT, errors may be lost: $!";
    exec('/bin/tar', 'czf', '/nonexistent/test.tar.gz', '.')
        or die("Unable to exec: $!")
}

local $/ = undef;
my $output .= <CMD>;

close(CMD);

if    ($? == -1) { die("Can't close pipe: $!\n"); }
elsif ($? & 127) { die("tar died from signal ", ($? & 127), "\n"); }
elsif ($? >> 8)  { die("tar exited with error ", ($? >> 8), "\n"); }

print $output;
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tar died from signal 13
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