diff options
Diffstat (limited to 'pod/perlvar.pod')
| -rw-r--r-- | pod/perlvar.pod | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/pod/perlvar.pod b/pod/perlvar.pod index 248c378614..f0447cd58f 100644 --- a/pod/perlvar.pod +++ b/pod/perlvar.pod @@ -397,16 +397,26 @@ L<perlfunc/formline()>. =item $? The status returned by the last pipe close, back-tick (C<``>) command, -or system() operator. Note that this is the status word returned by -the wait() system call, so the exit value of the subprocess is actually -(C<$? E<gt>E<gt> 8>). Thus on many systems, C<$? & 255> gives which signal, -if any, the process died from, and whether there was a core dump. -(Mnemonic: similar to B<sh> and B<ksh>.) +or system() operator. Note that this is the status word returned by the +wait() system call (or else is made up to look like it -- see L<$^S>). +Thus, the exit value of the subprocess is actually (C<$? E<gt>E<gt> 8>), +and C<$? & 255> gives which signal, if any, the process died from, and +whether there was a core dump. (Mnemonic: similar to B<sh> and B<ksh>.) Inside an C<END> subroutine C<$?> contains the value that is going to be given to C<exit()>. You can modify C<$?> in an C<END> subroutine to change the exit status of the script. +=item $SYSTEM_CHILD_STATUS + +=item $^S + +The status returned by the last pipe close, back-tick (C<``>) command, or +system() operator, in the native system format. On UNIX and UNIX-like +systems, C<$^S> is a synonym for C<$?>. Elsewhere, C<$^S> can be used to +determine aspects of child status that are system-specific. Check C<$^O> +before using this variable. (Mnemonic: System-Specific Subprocess Status.) + =item $OS_ERROR =item $ERRNO @@ -426,9 +436,8 @@ operator. (Mnemonic: What just went bang?) =item $^E -More specific information about the last system error than that -provided by C<$!>, if available. (If not, it's just C<$!> again, except under -OS/2.) +More specific information about the last system error than that provided by +C<$!>, if available. (If not, it's just C<$!> again, except under OS/2.) At the moment, this differs from C<$!> under only VMS and OS/2, where it provides the VMS status value from the last system error, and OS/2 error code of the last call to OS/2 API which was not directed via CRT. The |