Beefy Boxes and Bandwidth Generously Provided by pair Networks
No such thing as a small change

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
`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.


Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

In reply to Re^2: Effect of redirecting output to /dev/null on $? value by afoken
in thread Effect of redirecting output to /dev/null on $? value by Special_K

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others taking refuge in the Monastery: (5)
    As of 2021-01-25 20:34 GMT
    Find Nodes?
      Voting Booth?