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From: dick@ahds.UUCP (Dick Heijne CCS/TS)
Newsgroups: comp.unix.misc
Subject: Re: system cmmand
Keywords: system sh
Message-ID: <1980@ahds.UUCP>
Date: 24 Apr 91 09:46:32 GMT
Article-I.D.: ahds.1980
References: <1628@babcock.cerc.wvu.wvnet.edu>
Organization: Ahold NV, Zaandam, Netherlands, EEC
Lines: 23

In article <1628@babcock.cerc.wvu.wvnet.edu>, abmg@cathedral.cerc.wvu.wvnet.edu (Aliasghar Babadi) writes:
> Hi,
> 
> 	I run a program using the system command similar to the following
> 
>            system("prog &");
> 
>         for some programs I lose the stdin inputs. For some others get
> a lots of stdin input. What am I doing wrong? thanks in advance.
See User Manual (SysV): sh(1) or (Xenix): sh(C) approx. pp. 9:

	" If a command is followed by & the default standard input for
	  the command is the empty file /dev/null. Otherwise, the 
	  environment for the execution of a command contains the file
	  descriptors of the invoking shell etc....."

Remember that system(3C) does a "sh -c" to do it's job, so rules apply
to sh(1).
This explains situations where you don't get stdin input at all.
Situations where you get lots(???) of stdin input must be explainable
by the way the argument to system() is formatted.

Dick.