fig18_01.pl

PERL语言资料 可以用于PERL程序设计

#!/usr/bin/perl
# Fig. 18.1: fig18_01.pl
# Using fork to create child processes.

use warnings;
use strict;

my ( $start, $middle, $end, $pid );
$| = 1;

$start = time();

if ( $pid = fork() ) {
   sleep( 1 );
   print( "Parent executing.\n" );
   sleep( 2 );
   print( "Parent finished.\n" );
}
elsif ( defined( $pid ) ) {
   sleep( 1 );
   print( "Child executing.\n" );
   sleep( 2 );
   print( "Child finished.\n" );
   exit();
}
else {
   die( "Could not fork" );
}

$middle = time();

print( "That took " );
print( $middle - $start );
print( " seconds with fork.\n" );

sleep( 3 );
sleep( 3 );
$end = time();

print( "That took " );
print( $end - $middle );
print( " seconds without fork.\n" );
print( "Total of ", ( $end - $start ), " seconds.\n" );


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