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From: bzs@bu-cs.BU.EDU (Barry Shein)
Newsgroups: comp.unix.questions
Subject: Re: easy, basic, question...
Message-ID: <36833@bu-cs.BU.EDU>
Date: 21 Aug 89 02:21:30 GMT
References: <11072@neon.Stanford.EDU>
Organization: Boston U. Comp. Sci.
Lines: 25


From: wolfe@neon.stanford.edu (Michael R. Wolfe)
>I know how to call Unix commands from C:  system(string), but
>I'm having trouble coming up with the commands in string form
>from inside of a program.  That is, I'm being forced to do
>multiple strcat's to form a string to send to system.  Is there a
>way around this?

sprintf() should help a lot with this.

>In addition, is there any way to find the result of a unix command
>called from C without having to send it to a file and then open
>the file.  For example, I'm trying to use grep from C, which forces
>me to make a string such as "grep file >> anotherfile" using strcat,
>use "system" to call it, and then go and open "anotherfile" afterwards
>to find the result.  Has anyone come up with a better way?

See popen(3) which returns a pipe to/from the command.
-- 
	-Barry Shein

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