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Full Discussion: fork function
Top Forums UNIX for Dummies Questions & Answers fork function Post 46843 by Perderabo on Tuesday 27th of January 2004 07:22:47 PM
Old 01-27-2004
Since your code is running, it is already a process. Think about this program:

int main()
{
exit(0);
}

This is perfectly valid program. Note that it did not need to fork. But the shell had to fork to run it.

When you execute a line of code like:

pid=fork();

A complete copy of the process springs into existence. Both copies store something in pid. And then both copies continue with the next statement.

But they store a different value in pid. That's how the programmer can make parent and child do something different.

The child will store 0 in pid.

The parent will store the pid of the child in pid.

fork() is a system call. This is, it asks the kernel to do something. The kernel must pick a pid for the child. The algorithm is a little complex, but you don't need to know the gory details at this point. But you can be sure that it is not exactly random and it will pick a pid not currently in use.
 

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LEARN ABOUT DEBIAN

graphics::primitive::insets

Graphics::Primitive::Insets(3pm)			User Contributed Perl Documentation			  Graphics::Primitive::Insets(3pm)

NAME

       Graphics::Primitive::Insets - Space between things

DESCRIPTION

       Graphics::Primitive::Insets represents the amount of space that surrounds something.  This object can be used to represent either padding
       or margins (in the CSS sense, one being inside the bounding box, the other being outside)

SYNOPSIS

	 use Graphics::Primitive::Insets;

	 my $insets = Graphics::Primitive::Insets->new({
	   top	   => 5,
	   bottom  => 5,
	   left    => 5,
	   right   => 5
	 });

METHODS

   Constructor
       new Creates a new Graphics::Primitive::Insets.

   Instance Methods
       as_array
	   Return these insets as an array in the form of top, right, bottom and left.

       bottom
	   Set/Get the inset from the bottom.

       equal_to
	   Determine if these Insets are equal to another.

       left
	   Set/Get the inset from the left.

       right
	   Set/Get the inset from the right.

       top Set/Get the inset from the top.

       zero
	   Sets all the insets (top, left, bottom, right) to 0.

AUTHOR

       Cory Watson, "<gphat@cpan.org>"

SEE ALSO

       perl(1)

COPYRIGHT &; LICENSE
       Copyright 2008-2010 by Cory G Watson.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.12.3							    2010-08-21					  Graphics::Primitive::Insets(3pm)
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