new version of popen(3)

John Ioannidis ji at garfield.columbia.edu
Mon Apr 7 03:59:25 AEST 1986


In article <201 at dcc1.UUCP>, douglas at dcc1.UUCP (Douglas B. Jones) writes:
> 
> 	Hi,
> 
> 	  In the routine popen(3), a program can open either a read pipe
> 	or a write pipe to a sub-process (usually a program, like more).
> 	Does any one have a similar routine that will allow a person to
> 	have a read/write pipe to a sub-process. 
	....
> 	  This would be a very helpful program. I imagine it would have
> 	to deal with sockets(). 

	Quite some time ago I had posted to net.unix-wizards my version 
of a read-and-write popen. It had a slightly different calling sequence,
and used pty's instead of either pipes or socketpairs. This has some
advantages, like being able to get back prompts from the child process;
some programs check isatty(1) and don't output a prompt if it is not.
(for example, ftp(1)).
Anyway, check older postings for my program.

>	What would be really nice, is if two version
> 	of this popen2() could be written. One to allow the calling program
> 	to work with a child process on the local system, and secondly to
> 	allow it (the calling program) to work with a child process on
> 	another system (in the local network).
> 

I guess, you can just use /usr/ucb/rsh instead of /bin/sh for the shell 
in popen or whatever. This also takes care of security; you won't have
to implement Yet Another security/user authorization/whatever scheme.

Hope all that helps,
 - john

#include <appropriate_disclaimers>

VOICE: 	+1 212 280 5510			ARPA: ioannidis at cs.columbia.EDU
USnail:	John Ioannidis			      ji at garfield.columbia.EDU
	450 Computer Science
	Columbia University,		USENET: ...{seismo|topaz}!
	New York, NY 10027			   columbia!garfield!ji

			... It's all Greek to me!



More information about the Comp.unix.wizards mailing list