Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!wuarchive!udel!princeton!phoenix!pfalstad
From: pfalstad@phoenix.Princeton.EDU (Paul John Falstad)
Newsgroups: comp.unix.questions
Subject: Re: Interfacing C Code to Shell Script
Keywords: popen sucks  ;-)
Message-ID: <16890@phoenix.Princeton.EDU>
Date: 31 May 90 04:06:26 GMT
References: <23487@adm.BRL.MIL> <16870@phoenix.Princeton.EDU> <11985@cbmvax.commodore.com>
Reply-To: pfalstad@phoenix.Princeton.EDU (Paul John Falstad)
Organization: Princeton University, NJ
Lines: 25

In article <11985@cbmvax.commodore.com> ag@cbmvax (Keith Gabryelski) writes:
>In article <16870@phoenix.Princeton.EDU> subbarao@phoenix.Princeton.EDU
>(Kartik Subbarao) writes:
>>In article <23487@adm.BRL.MIL> rose@baby.swmed.utexas.edu (Rose Oguz) writes:
>>>	I want to call a shell script from my C program.  However, I 
>>>would like the script to return values to my C program.  Is there a
                                        ^
>>this one simply says that popen() is screaming for this job, just as it's
>or just:
>
>	int retval = system("myshellscript");

This only works for one integer return value that is < 128, of course.
If you need more than that you'll have to do a popen.

Also, for a command as simple as "myshellscript," I would have used
fork, execve, and wait, to save on the overhead of sh.  Even instead of
popen it might be a good idea to try fork, execve, and pipe...
Just a thought.

-- 
Paul Falstad  PLINK:Hypnos GEnie:P.FALSTAD net:pfalstad@phoenix.princeton.edu
Disclaimer: My opinions, which belong to me and which I own, are mine.
-Anne Elk (not AN elk!)  The sun never set on the British empire because
the British empire was in the East and the sun sets in the West.