System() function

[Michael J. Chinni, SMCAR-CCS-E]

Vilva,

>I am trying to do system("man cat | wc -c") in my program, and i need
>to store the value returned by "wc" in a variable declared in my program.
>I dont want to redirect it to a file and then read from the file.

The way to do this is via a "popen". Small segment of code to do this follows:
#include <stdio.h>
main()
{	FILE	*pipe;
	int	chars;

	pipe=popen("man cat | wc -c", "r");
	fscanf(pipe, "%d", &chars);
	pclose(pipe);
}

This gets the result of "man cat | wc -c" and stores it in chars. This code
doesn't do any error checking (like on the value of pipe after the popen to
check the success of the popen; on the return status of the fscanf, or the
return status of the pclose).

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			    Michael J. Chinni
              Simulation Techniques and Workplace Automation Team
	 US Army Armament Research, Development, and Engineering Center
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    and dust covered workstation      () ARPA: mchinni at pica.army.mil
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