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| author | Jarkko Hietaniemi <jhi@iki.fi> | 2001-12-26 18:58:09 +0000 |
|---|---|---|
| committer | Jarkko Hietaniemi <jhi@iki.fi> | 2001-12-26 18:58:09 +0000 |
| commit | 9d6eb86e4075182b9cda16d90e5d387c1537d687 (patch) | |
| tree | c8b073abff2544db5ebf74b2ba6eb81d0ae9b13d /pod/perlport.pod | |
| parent | a2a978ac74e3f07d5ba28e7a4d1f1e4ae67ce129 (diff) | |
| download | perl-9d6eb86e4075182b9cda16d90e5d387c1537d687.tar.gz | |
Bad $? assumptions.
p4raw-id: //depot/perl@13891
Diffstat (limited to 'pod/perlport.pod')
| -rw-r--r-- | pod/perlport.pod | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/pod/perlport.pod b/pod/perlport.pod index 588b55d14b..a2133484dd 100644 --- a/pod/perlport.pod +++ b/pod/perlport.pod @@ -1779,6 +1779,16 @@ OS>, OS/390, VM/ESA) =item system LIST +In general, do not assume the UNIX/POSIX semantics that you can shift +the C<$?> left by eight to get the exit value, or that C<$? & 127> +would give you the number of the signal that terminated the program, +or that C<$? & 128> would test true if the program was terminated by a +coredump. Instead, use the POSIX W*() interfaces: for example, use +WIFEXITED($?) an WEXITVALUE($?) to test for a normal exit and the exit +value, and WIFSIGNALED($?) and WTERMSIG($?) for a signal exit and the +signal. Core dumping is not a portable concept so there's no portable +way to test for that. + Only implemented if ToolServer is installed. (S<Mac OS>) As an optimization, may not call the command shell specified in |