End of subroutine

sandy_1028 has asked for the wisdom of the Perl Monks concerning the following question:

sub functionname {

#       system("sh processkill $childpid");
        print"time out entered into sigalrmhandler";###############TEM
+P LINE-----------> PS
        if($cmd =~ /aaa/){
               $tmpkill ="";
               # code here 

        syscall(&SYS_close, fileno(CMD));

}

1;

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Replies are listed 'Best First'.
Re: End of subroutine by mpeever (Friar) on Nov 07, 2008 at 05:15 UTC
The 1 isn't at the end of the subroutine: the subroutine ends with the '}'. The '1' typically marks the end of a module, as modules need to "return" a true value. From the Simple Module Tutorial: We need the 1; at the end because when a module loads Perl checks to see that the module returns a true value to ensure it loaded OK. You could put any true value at the end (see Code::Police) but 1 is the convention.	[reply]
Re: End of subroutine by marcussen (Pilgrim) on Nov 07, 2008 at 05:21 UTC
It is used outside the subroutine, your question is actually: why is 1; used at the end of a module? A use statement (as in use module;) evals the contents of a file. The last expression in the file must evaluate to true, or the eval dies. UPDATE: Correction of my statement by ikegami (see below); Confucius says kill mosquito unless cannon	[reply]
Re^2: End of subroutine by ikegami (Patriarch) on Nov 07, 2008 at 05:29 UTC
A use statement (as in use module;) evals the contents of a file. The last expression in the file must evaluate to true, or the eval dies. Not quite. `eval` never dies based on the value returned by the evaluated expression. `>perl -e"eval { 0 }" >` [download] `require` (and thus `use`) dies if the values returned by the module is false. `>copy nul Module.pm 1 file(s) copied. >perl -e"use Module;" Module.pm did not return a true value at -e line 1. BEGIN failed--compilation aborted at -e line 1. >echo 1; > Module.pm >perl -e"use Module;" >` [download]	[reply] [d/l] [select]


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