Handle a signal: Difference between revisions
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Add SIGQUIT since per the task description SIGQUIT is more appropriate that SIGINT (see perl example) see discussion. |
demonstrate the power or signal handling |
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=={{header|Perl}}==
Before version 5.8 <tt>sleep</tt> requires an integer argument, so we'll spin (There exist more obtuse methods)
<lang perl>
my $start = time; # seconds since epohc
my $arlm=5; # every 5 seconds show how we're doing
my $i;
$SIG{QUIT} = sub
{print " Ran for ", time - $start, " seconds.\n"; die; };
$SIG{INT} = sub
{print
$SIG{ALRM} = sub
{print " After $arlm seconds i= $i. Executing for ", time - $start, " seconds.\n"; alarm $arlm };
alarm $arlm; # trigger ALaRM after we've run for a while
print " ^C to inerrupt, ^\\ to quit, takes a break at $arlm seconds \n";
while ( 1 ) {
for ( $w=11935000; $w--; $w>0 ){}; # spinning is bad, but hey it's only a demo
}
^C to inerrupt, ^\ to quit, takes a break at 5 seconds
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^C Running for 1 seconds.
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^C Running for 2 seconds.
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^C Running for 3 seconds.
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After 5 seconds i= 10. Executing for 5 seconds.
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After 5 seconds i= 20. Executing for 10 seconds.
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^\ Ran for 11 seconds.
Died at 0.pl line 6..
▲ {print ++$n, "\n";}</lang>
This example does the required task:
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