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getgrent.c revision 1.3 
      1 /*	$NetBSD: getgrent.c,v 1.3 1999/03/13 19:08:44 sommerfe Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  * Portions Copyright (c) 1994, Jason Downs. All Rights Reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 /*
     38  * Copied from:  lib/libc/gen/getgrent.c
     39  * and then gutted, leaving only /etc/group support.
     40  */
     41 
     42 #include <sys/types.h>
     43 #include <stdio.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 #include <grp.h>
     47 
     48 static FILE *_gr_fp;
     49 static struct group _gr_group;
     50 static int _gr_stayopen;
     51 static int grscan __P((int, int, const char *));
     52 static int start_gr __P((void));
     53 
     54 #define	MAXGRP		200
     55 static char *members[MAXGRP];
     56 #define	MAXLINELENGTH	1024
     57 static char line[MAXLINELENGTH];
     58 
     59 struct group *
     60 getgrent()
     61 {
     62 	if ((!_gr_fp && !start_gr()) || !grscan(0, 0, NULL))
     63 		return(NULL);
     64 	return(&_gr_group);
     65 }
     66 
     67 struct group *
     68 getgrnam(name)
     69 	const char *name;
     70 {
     71 	int rval;
     72 
     73 	if (!start_gr())
     74 		return(NULL);
     75 	rval = grscan(1, 0, name);
     76 	if (!_gr_stayopen)
     77 		endgrent();
     78 	return(rval ? &_gr_group : NULL);
     79 }
     80 
     81 struct group *
     82 #ifdef __STDC__
     83 getgrgid(gid_t gid)
     84 #else
     85 getgrgid(gid)
     86 	gid_t gid;
     87 #endif
     88 {
     89 	int rval;
     90 
     91 	if (!start_gr())
     92 		return(NULL);
     93 	rval = grscan(1, gid, NULL);
     94 	if (!_gr_stayopen)
     95 		endgrent();
     96 	return(rval ? &_gr_group : NULL);
     97 }
     98 
     99 static int
    100 start_gr()
    101 {
    102 	if (_gr_fp) {
    103 		rewind(_gr_fp);
    104 		return(1);
    105 	}
    106 	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
    107 }
    108 
    109 void
    110 setgrent()
    111 {
    112 	(void) setgroupent(0);
    113 }
    114 
    115 int
    116 setgroupent(stayopen)
    117 	int stayopen;
    118 {
    119 	if (!start_gr())
    120 		return(0);
    121 	_gr_stayopen = stayopen;
    122 	return(1);
    123 }
    124 
    125 void
    126 endgrent()
    127 {
    128 	if (_gr_fp) {
    129 		(void)fclose(_gr_fp);
    130 		_gr_fp = NULL;
    131 	}
    132 }
    133 
    134 static int
    135 grscan(search, gid, name)
    136 	register int search, gid;
    137 	register const char *name;
    138 {
    139 	register char *cp, **m;
    140 	char *bp;
    141 
    142 	for (;;) {
    143 		if (!fgets(line, sizeof(line), _gr_fp))
    144 			return(0);
    145 		bp = line;
    146 		/* skip lines that are too big */
    147 		if (!strchr(line, '\n')) {
    148 			int ch;
    149 
    150 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
    151 				;
    152 			continue;
    153 		}
    154 		_gr_group.gr_name = strsep(&bp, ":\n");
    155 		if (search && name && strcmp(_gr_group.gr_name, name))
    156 			continue;
    157 		_gr_group.gr_passwd = strsep(&bp, ":\n");
    158 		if (!(cp = strsep(&bp, ":\n")))
    159 			continue;
    160 		_gr_group.gr_gid = atoi(cp);
    161 		if (search && name == NULL && _gr_group.gr_gid != gid)
    162 			continue;
    163 		cp = NULL;
    164 		if (bp == NULL)
    165 			continue;
    166 		for (m = _gr_group.gr_mem = members;; bp++) {
    167 			if (m == &members[MAXGRP - 1])
    168 				break;
    169 			if (*bp == ',') {
    170 				if (cp) {
    171 					*bp = '\0';
    172 					*m++ = cp;
    173 					cp = NULL;
    174 				}
    175 			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
    176 				if (cp) {
    177 					*bp = '\0';
    178 					*m++ = cp;
    179 				}
    180 				break;
    181 			} else if (cp == NULL)
    182 				cp = bp;
    183 		}
    184 		*m = NULL;
    185 		return(1);
    186 	}
    187 	/* NOTREACHED */
    188 }
    189