in reply to Re: Effect of redirecting output to /dev/null on $? value
in thread Effect of redirecting output to /dev/null on $? value
`exec my_executable_that_seg_faults > /dev/null`;
exec at the start of a command is one of the few things that are treated specially in Perl_do_exec3(), see Re^2: Improve pipe open? (redirect hook). It seems to disable the default optimization and forces the use of the default shell.
There is a way to stay mentally sane on Unix/POSIX systems for I/O-redirection. Don't use system; instead, fork and exec manually:
# (untested) my $pid=fork(); my @cmd_and_args=('my_executable_that_seg_faults'); # maybe push @cmd_and_args,qw( some arguments for the program ); defined($pid) or die "Can't fork: $!"; if ($pid) { # parent process waitpid $pid; #<-- sets $? } else { # child process open STDOUT,'>','/dev/null' or die "Can't redirect STDOUT: $!"; exec { $cmd_and_args[0] } @cmd_and_args; die "exec failed: $!"; }
Note that ONLY indirect object notation on exec prevents all attempts of perl to be smart. See The problem of "the" default shell.
Alexander
--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
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Re^3: Effect of redirecting output to /dev/null on $? value
by jcb (Parson) on Aug 05, 2020 at 00:01 UTC | |
by ikegami (Patriarch) on Aug 05, 2020 at 04:11 UTC | |
Re^3: Effect of redirecting output to /dev/null on $? value
by ikegami (Patriarch) on Aug 05, 2020 at 04:03 UTC |
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