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Full Discussion: will child processes be created when executing "ps"?
Top Forums Shell Programming and Scripting will child processes be created when executing "ps"? Post 302506660 by rbatte1 on Monday 21st of March 2011 02:07:30 PM
Old 03-21-2011
Could you tell us a little more, such as which operating system and any more about the script you are look for. Different operaing systems have variations on the ps command and it would be worth seeing the script to look for anything that might cause child processes.

ps in itself should not cause your script to spawn processes, but it may find itself which can be random depending on how the process gets scheduled in by the OS e.g.
Code:
$ ps -ef|grep myscript
12321 12311 0 11:22:33 pts/0 0:01 /home/fred/myscript
12335 12311 0 11:22:33 pts/0 0:01 ps -ef|grep myscript

You can get out of this random catch by using square brackets to exploit the shell expansion:-
Code:
$ ps -ef|grep myscrip[t]
12321 12311 0 11:22:33 pts/0 0:01 /home/fred/myscript

This will never match itself, but will find all variations of the phrase myscrip followed by anything in the brackets, um, that's a t then.


Let us know and hopefully someone can find the issue.





Robin
Liverpool/Blackburn
UK
 

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LEARN ABOUT DEBIAN

empty-page

EMPTY-PAGE(1)							 ExactImage Manual						     EMPTY-PAGE(1)

NAME

       empty-page - empty page detector of the ExactImage toolkit

SYNOPSIS

       empty-page [option...] {-i | --input} input-file

       empty-page {-h | --help}

DESCRIPTION

       ExactImage is a fast C++ image processing library. Unlike many other library frameworks it allows operation in several color spaces and bit
       depths natively, resulting in low memory and computational requirements.

       empty-page counts dark pixels of a black and white image and decides with a threshold whether the page is most probably empty, and thus can
       be removed from the image processing stream.

OPTIONS

       -i file, --input file
	   Read image from the specified file.

       -m n, --margin n
	   Set width of border margin to skip. For speed reasons, the margin has to be a multiple of 8. The default is 16.

       -p x, --percentage x
	   Set fraction of permissible dark pixels. The default is 0.05 (5%).

       -h, --help
	   Display help text and exit.

EXAMPLES

	   $ empty-page -i test.tif
	   The image has 75461 dark pixels from a total of 1060992 (7.11231%).
	   non-empty

EXIT STATUS

       The exit status is 0 if the image is mostly white, 1 otherwise.

SEE ALSO

       exactimage(7)

AUTHORS

       Jakub Wilk <jwilk@debian.org>
	   Wrote this manual page for the Debian system.

       http://www.exactcode.de/site/open_source/exactimage/
	   This manual page incorporates texts found on the ExactImage homepage.

COPYRIGHT

       This manual page was written for the Debian system (and may be used by others).

       Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 or (at
       your option) any later version published by the Free Software Foundation.

       On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL-2.

empty-page							    09/09/2013							     EMPTY-PAGE(1)
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