Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!jarthur!uunet!rushpc!jjr
From: jjr@rushpc (John J. Rushford Jr)
Newsgroups: comp.lang.c
Subject: Novice question on vectors of pointers
Message-ID: <1991Apr29.051313.2064@rushpc>
Date: 29 Apr 91 05:13:13 GMT
Organization: My place on the Front Range
Lines: 43



I hope this question is not too OS specific.  Point me elsewhere if it is.

How does one use a vector of pointers to member names.  I'm specifically
trying to use getgrnam(3C) in UNIX SVR3.2 and I want to print to 'stdout'
all the entries in **gr_mem.  Below is an example of what I'm trying to
work with.  I don't have any problem with the remaining elements in the
structure.  It's **gr_mem I don't understand.  How do you work with it?

EXAMPLE:

#include <stdio.h>
	
/* From '/usr/include/grp.h'
struct group {
	char *gr_name;    /* the name of the group */
	char *gr_passwd;  /* the encrypted group password */
	int  gr_gid;      /* the numerical group ID */
	char **gr_mem;    /* vector of pointer to member names */
	};

struct group *pntr, *getgrnam();

main()
{
	pntr = getgrnam("other");

	fprintf(stdout, "%s\n", pntr->gr_name);
	fprintf(stdout, "%s\n", pntr->gr_passwd);
	fprintf(stdout, "%d\n", pntr->gr_gid);
	

	return 0;
}


thanks a ton.
-- 

John
----
Westminster Colorado