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Diffstat (limited to 'pod/perlvar.pod')
| -rw-r--r-- | pod/perlvar.pod | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/pod/perlvar.pod b/pod/perlvar.pod index a049e9d5a1..de9bd22348 100644 --- a/pod/perlvar.pod +++ b/pod/perlvar.pod @@ -698,6 +698,22 @@ sometimes it's a string representing the function, and sometimes it's going to call the subroutine call right then and there! Best to be sure and quote it or take a reference to it. *Plumber works too. See L<perlsub>. +If your system has the sigaction() function then signal handlers are +installed using it. This means you get reliable signal handling. If +your system has the SA_RESTART flag it is used when signals handlers are +installed. This means that system calls for which it is supported +continue rather than returning when a signal arrives. If you want your +system calls to be interrupted by signal delivery then do something like +this: + + use POSIX ':signal_h'; + + my $alarm = 0; + sigaction SIGALRM, new POSIX::SigAction sub { $alarm = 1 } + or die "Error setting SIGALRM handler: $!\n"; + +See L<POSIX>. + Certain internal hooks can be also set using the %SIG hash. The routine indicated by C<$SIG{__WARN__}> is called when a warning message is about to be printed. The warning message is passed as the first |