Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
A "signal" is a way for your program to process "asynchronous" events. Meaning that you register a subroutine to be called when that event occurs. When you do this, you don't have to explictly keep checking that a particular event occured, the OS will call the sub when that event occurs.

kill ALRM, $$ doesn't make sense to me!

The below code shows a simple example of a handler for SIGALRM.

#!/usr/bin/perl -w use strict; #$|=1; #see note below... $SIG{'ALRM'} = 'timeout'; alarm(1); while (1){sleep(1);} sub timeout { print "stdout: Alarming!\n"; print STDERR "stderr: Alarming!\n"; exit(0); }; __END__ prints: Note: stderr msg comes first because "autoflush" for stdout wasn't turned on (stdout normally doesn't get "flushed" until program end). $|=1; turns autoflush on. stderr: Alarming! stdout: Alarming!
Kill $some_number makes no sense if $some_number is not a PID. kill ALRM doesn't have a PID. ALRM on my system is "numeric 14", but that is just shorthand for what the string ALRM means.

In reply to Re: Signals in Strawberry Perl: Name or number? by Marshall
in thread Signals in Strawberry Perl: Name or number? by bv

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others romping around the Monastery: (2)
    As of 2018-02-25 18:00 GMT
    Find Nodes?
      Voting Booth?
      When it is dark outside I am happiest to see ...

      Results (314 votes). Check out past polls.