glibc/pwd/pwdread.c

148 lines
3.2 KiB
C

/* Copyright (C) 1991, 1992, 1995 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 <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pwd.h>
#include <sys/types.h>
/* This is the function that all the others are based on.
The format of the password file is known only here. */
/* Structure containing info kept by each __pwdread caller. */
typedef struct
{
char *buf;
size_t buflen;
struct passwd p;
} pwdread_info;
/* Return a chunk of memory containing a pre-initialized `pwdread_info'. */
PTR
DEFUN_VOID(__pwdalloc)
{
pwdread_info *info = (PTR) malloc (sizeof(pwdread_info));
if (info == NULL)
return NULL;
info->buf = NULL;
info->buflen = 0;
return info;
}
/* Read a password entry from STREAM, filling in P. */
struct passwd *
DEFUN(__pwdread, (stream, p), FILE *stream AND PTR CONST p)
{
register pwdread_info *CONST info = (pwdread_info *) p;
char *start, *end;
/* 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->p.pw_name = start;
start = end + 1;
end = strchr (start, ':');
if (end == NULL)
return NULL;
*end = '\0';
info->p.pw_passwd = start;
info->p.pw_uid = (uid_t) strtol (end + 1, &end, 10);
if (*end != ':')
return NULL;
info->p.pw_gid = (gid_t) strtol (end + 1, &end, 10);
if (*end != ':')
return NULL;
start = end + 1;
end = strchr (start, ':');
if (end == NULL)
return NULL;
*end = '\0';
info->p.pw_gecos = start;
start = end + 1;
end = strchr (start, ':');
if (end == NULL)
return NULL;
*end = '\0';
info->p.pw_dir = start;
start = end + 1;
end = strchr (start, '\n');
if (end == NULL)
return NULL;
*end = '\0';
info->p.pw_shell = start;
return &info->p;
}
struct passwd *
__pwdscan (void **info, int (*selector) (struct passwd *))
{
FILE *stream;
struct passwd *p;
if (*info == NULL)
{
*info = __pwdalloc ();
if (info == NULL)
return NULL;
}
stream = __pwdopen ();
if (stream == NULL)
return NULL;
p = NULL;
while (! feof (stream))
{
p = __pwdread (stream, *info);
if (p && (*selector) (p))
break;
p = NULL;
}
(void) fclose (stream);
return p;
}