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Full Discussion: How this works?
Top Forums UNIX for Advanced & Expert Users How this works? Post 302449534 by carolsanjeevi on Monday 30th of August 2010 11:54:33 PM
Old 08-31-2010
Question How this works?

I have a program............
Code:
#include<stdio.h>
#include<unistd.h>
main()
{
if(fork == 0)
{
printf("Hi every body:p!!!!!!!!!!");
}
}

This program works with out any error. here fork is not a system call. It just act as a variable.But how it works without declaring it? What data type it is?

Please help me to get a solution. I have tried all . But i cant come out with an answer.Smilie

Last edited by pludi; 08-31-2010 at 02:26 AM.. Reason: code tags, please...
 

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IO::Async::PID(3pm)					User Contributed Perl Documentation				       IO::Async::PID(3pm)

NAME
"IO::Async::PID" - event callback on exit of a child process SYNOPSIS
use IO::Async::PID; use POSIX qw( WEXITSTATUS ); use IO::Async::Loop; my $loop = IO::Async::Loop->new; my $kid = $loop->fork( code => sub { print "Child sleeping.. "; sleep 10; print "Child exiting "; return 20; }, ); print "Child process $kid started "; my $pid = IO::Async::PID->new( pid => $kid, on_exit => sub { my ( $self, $exitcode ) = @_; printf "Child process %d exited with status %d ", $self->pid, WEXITSTATUS($exitcode); }, ); $loop->add( $pid ); $loop->run; DESCRIPTION
This subclass of IO::Async::Notifier invokes its callback when a process exits. For most use cases, a IO::Async::Process object provides more control of setting up the process, connecting filehandles to it, sending data to and receiving data from it. EVENTS
The following events are invoked, either using subclass methods or CODE references in parameters: on_exit $exitcode Invoked when the watched process exits. PARAMETERS
The following named parameters may be passed to "new" or "configure": pid => INT The process ID to watch. Must be given before the object has been added to the containing "IO::Async::Loop" object. on_exit => CODE CODE reference for the "on_exit" event. Once the "on_exit" continuation has been invoked, the "IO::Async::PID" object is removed from the containing "IO::Async::Loop" object. METHODS
$process_id = $pid->pid Returns the underlying process ID $pid->kill( $signal ) Sends a signal to the process AUTHOR
Paul Evans <leonerd@leonerd.org.uk> perl v5.14.2 2012-10-24 IO::Async::PID(3pm)
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