Article 137054 of comp.os.vms:
Path: nntpd.lkg.dec.com!eps.enet.dec.com!vandenheuvel
From: vandenheuvel@eps.enet.dec.com (Hein RMS van den Heuvel)
Newsgroups: comp.os.vms
Subject: Re: popen in vms
Date: 2 JAN 96 23:57:20
Organization: Digital Equipment Corporation
Lines: 44
Message-ID: <4cd36g$b61@nntpd.lkg.dec.com>
References: <9512291618.AA14035@w231zrz.zrz.TU-Berlin.DE>
NNTP-Posting-Host: epsys.enet.dec.com


In article <9512291618.AA14035@w231zrz.zrz.TU-Berlin.DE>, manschbf@w214zrz.zrz.TU-Berlin.DE (Nazim Manser) writes...
>hi all!
> 
>i looked for popen("command","operation") in vaxc run-time_functions 
>but i didn't find it.
>is there a way to do the same (like popen in un*x) in vms ?

Check out calling LIB$FIND_FILE (and LIB$FIND_FILE_END when done)
Once you figure out how to do the descriptors, this should prove
a convenient way to 'find files', returning names in a loop.

[For added hackers bonus points, open up that supposedly opaque 'context'
parameter to the call. You'll find a pointer to a useable FAB + NAME ]

#include descrip
#include rmsdef
main()
{
    int	stat, stv, context = 0;
    $DESCRIPTOR (loop, "Loop  ? ");
    $DESCRIPTOR (more, "More... ");
    $DESCRIPTOR (wild, "[.tmp]*.*");
    struct dsc$descriptor_d temp_dx, file_name_dx = 
					{0, DSC$K_DTYPE_T, DSC$K_CLASS_D, 0} ;
    temp_dx = file_name_dx;
    while (1 & lib$get_input ( &temp_dx, &loop ))
    {    
	while ( 1 & ( stat = 
		lib$find_file( &wild, &file_name_dx, &context, 0, 0, &stv, 0)))
	{
	    lib$put_output ( &file_name_dx);
	    lib$get_input ( &temp_dx, &more);
	}
	lib$find_file_end ( &context );
	if (stat != RMS$_NMF) return (stat);
    }
}


Hope this helps,		+--------------------------------------+
Hein van den Heuvel, Digital.	| All opinions expressed are mine, and |
  "Makers of VMS and other	| may not reflect those of my employer |
   fine Operating Systems."	+--------------------------------------+