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getgrent.c revision 1.2.4.2 
      1 /*	$NetBSD: getgrent.c,v 1.2.4.2 1995/10/13 18:10:24 gwr 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(), start_gr();
     52 
     53 #define	MAXGRP		200
     54 static char *members[MAXGRP];
     55 #define	MAXLINELENGTH	1024
     56 static char line[MAXLINELENGTH];
     57 
     58 struct group *
     59 getgrent()
     60 {
     61 	if (!_gr_fp && !start_gr() || !grscan(0, 0, NULL))
     62 		return(NULL);
     63 	return(&_gr_group);
     64 }
     65 
     66 struct group *
     67 getgrnam(name)
     68 	const char *name;
     69 {
     70 	int rval;
     71 
     72 	if (!start_gr())
     73 		return(NULL);
     74 	rval = grscan(1, 0, name);
     75 	if (!_gr_stayopen)
     76 		endgrent();
     77 	return(rval ? &_gr_group : NULL);
     78 }
     79 
     80 struct group *
     81 #ifdef __STDC__
     82 getgrgid(gid_t gid)
     83 #else
     84 getgrgid(gid)
     85 	gid_t gid;
     86 #endif
     87 {
     88 	int rval;
     89 
     90 	if (!start_gr())
     91 		return(NULL);
     92 	rval = grscan(1, gid, NULL);
     93 	if (!_gr_stayopen)
     94 		endgrent();
     95 	return(rval ? &_gr_group : NULL);
     96 }
     97 
     98 static int
     99 start_gr()
    100 {
    101 	if (_gr_fp) {
    102 		rewind(_gr_fp);
    103 		return(1);
    104 	}
    105 	return((_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0);
    106 }
    107 
    108 void
    109 setgrent()
    110 {
    111 	(void) setgroupent(0);
    112 }
    113 
    114 int
    115 setgroupent(stayopen)
    116 	int stayopen;
    117 {
    118 	if (!start_gr())
    119 		return(0);
    120 	_gr_stayopen = stayopen;
    121 	return(1);
    122 }
    123 
    124 void
    125 endgrent()
    126 {
    127 	if (_gr_fp) {
    128 		(void)fclose(_gr_fp);
    129 		_gr_fp = NULL;
    130 	}
    131 }
    132 
    133 static int
    134 grscan(search, gid, name)
    135 	register int search, gid;
    136 	register char *name;
    137 {
    138 	register char *cp, **m;
    139 	char *bp;
    140 
    141 	for (;;) {
    142 		if (!fgets(line, sizeof(line), _gr_fp))
    143 			return(0);
    144 		bp = line;
    145 		/* skip lines that are too big */
    146 		if (!strchr(line, '\n')) {
    147 			int ch;
    148 
    149 			while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
    150 				;
    151 			continue;
    152 		}
    153 		_gr_group.gr_name = strsep(&bp, ":\n");
    154 		if (search && name && strcmp(_gr_group.gr_name, name))
    155 			continue;
    156 		_gr_group.gr_passwd = strsep(&bp, ":\n");
    157 		if (!(cp = strsep(&bp, ":\n")))
    158 			continue;
    159 		_gr_group.gr_gid = atoi(cp);
    160 		if (search && name == NULL && _gr_group.gr_gid != gid)
    161 			continue;
    162 		cp = NULL;
    163 		if (bp == NULL)
    164 			continue;
    165 		for (m = _gr_group.gr_mem = members;; bp++) {
    166 			if (m == &members[MAXGRP - 1])
    167 				break;
    168 			if (*bp == ',') {
    169 				if (cp) {
    170 					*bp = '\0';
    171 					*m++ = cp;
    172 					cp = NULL;
    173 				}
    174 			} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
    175 				if (cp) {
    176 					*bp = '\0';
    177 					*m++ = cp;
    178 				}
    179 				break;
    180 			} else if (cp == NULL)
    181 				cp = bp;
    182 		}
    183 		*m = NULL;
    184 		return(1);
    185 	}
    186 	/* NOTREACHED */
    187 }
    188