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The status returned by the last pipe close, backtick (|
``) command, 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). Thus, the exit value of the subprocess is actually (
$? >> 8), and
$? & 255 gives which signal, if any, the process died from, and whether there was a
core dump. (Mnemonic: similar to sh and
Note that if you have installed a signal handler for
SIGCHLD, the value of
$? will usually be wrong outside that handler.
Inside an END subroutine
$? contains the value that is going to be given to exit(). You can modify
$? in an END subroutine to change the exit status of the script.
VMS, the pragma
use vmsish 'status' makes
$? reflect the actual
VMS exit status, instead of the default emulation of
Source: Perl predefined variables
Copyright: Larry Wall, et al.
(Corrections, notes, and links courtesy of RocketAware.com)
Up to: Current Process Control
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