glibc/grp/grpread.c
1995-02-18 01:27:10 +00:00

136 lines
3.1 KiB
C

/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <grp.h>
/* This is the function that all the others are based on.
The format of the group file is known only here. */
/* Structure containing info kept by each __grpread caller. */
typedef struct
{
char *buf;
size_t buflen;
size_t max_members;
char **members;
struct group g;
} grpread_info;
/* Return a chunk of memory containing a pre-initialized `grpread_info'. */
PTR
DEFUN_VOID(__grpalloc)
{
grpread_info *info = (PTR) malloc (sizeof(grpread_info));
if (info == NULL)
return NULL;
info->buf = NULL;
info->buflen = 0;
info->max_members = 5;
info->members = (char **) malloc (5 * sizeof(char *));
if (info->members == NULL)
{
free ((PTR) info);
return NULL;
}
return info;
}
/* Read a group entry from STREAM, filling in G. */
struct group *
DEFUN(__grpread, (stream, g), FILE *stream AND PTR CONST g)
{
register grpread_info *CONST info = (grpread_info *) g;
char *start, *end;
register size_t i;
/* Idiocy checks. */
if (stream == NULL)
{
errno = EINVAL;
return NULL;
}
do
if (__getline (&info->buf, &info->buflen, stream) == -1)
return NULL;
while (info->buf[0] == '#');
start = info->buf;
end = strchr (start, ':');
if (end == NULL)
return NULL;
*end = '\0';
info->g.gr_name = start;
start = end + 1;
end = strchr (start, ':');
if (end == NULL)
return NULL;
*end = '\0';
info->g.gr_passwd = start;
info->g.gr_gid = (gid_t) strtol (end + 1, &end, 10);
if (*end != ':')
return NULL;
i = 0;
do
{
start = end + 1;
end = strchr (start, ',');
if (end == NULL)
{
end = strchr (start, '\n');
if (end == start)
break;
if (end == NULL)
return NULL;
*end = '\0';
end = NULL;
}
else
*end = '\0';
if (i == info->max_members - 2)
{
info->max_members += 5;
info->members = (char **)
realloc ((PTR) info->members, info->max_members * sizeof (char *));
if (info->members == NULL)
return NULL;
}
info->members[i++] = start;
} while (end != NULL);
info->members[i] = NULL;
info->g.gr_mem = info->members;
return &info->g;
}