xref: /freebsd/usr.sbin/chkgrp/chkgrp.c (revision 83bc6a110657328dea5039ffa37ea447a295cb2d)
1 /*-
2  * Copyright (c) 1998 Dag-Erling Co�dan Sm�rgrav
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software withough specific prior written permission
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  *	$Id$
29  */
30 
31 static const char CVSID[] = "$Id$";
32 
33 #include <err.h>
34 #include <ctype.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <sysexits.h>
39 
40 extern char *__progname;
41 
42 void
43 usage(void)
44 {
45     fprintf(stderr, "usage: %s [groupfile]\n", __progname);
46     exit(EX_USAGE);
47 }
48 
49 int
50 main(int argc, char *argv[])
51 {
52     unsigned int len;
53     int n = 0, i, k, e = 0;
54     char *gfn, *line, *f[4], *p;
55     FILE *gf;
56 
57     /* check arguments */
58     switch (argc) {
59     case 1:
60 	gfn = "/etc/group";
61 	break;
62     case 2:
63 	gfn = argv[1];
64 	break;
65     default:
66 	gfn = NULL; /* silence compiler */
67 	usage();
68     }
69 
70     /* open group file */
71     if ((gf = fopen(gfn, "r")) == NULL)
72 	err(EX_IOERR, gfn); /* XXX - is IO_ERR the correct exit code? */
73 
74     /* check line by line */
75     while (++n) {
76 	if ((line = fgetln(gf, &len)) == NULL)
77 	    break;
78 	while (len && isspace(line[len-1]))
79 	    len--;
80 
81 	/* ignore blank lines and comments */
82 	for (p = line; p < (line + len); p++)
83 	    if (!isspace(*p)) break;
84 	if (!len || (*p == '#')) {
85 #if 0
86 	    /* entry is correct, so print it */
87 	    printf("%*.*s\n", len, len, line);
88 #endif
89 	    continue;
90 	}
91 
92 	/*
93 	 * A correct group entry has four colon-separated fields, the third
94 	 * of which must be entirely numeric and the fourth of which may
95 	 * be empty.
96 	 */
97 	for (i = k = 0; k < 4; k++) {
98 	    for (f[k] = line+i; (i < len) && (line[i] != ':'); i++)
99 		/* nothing */ ;
100 	    if ((k < 3) && (line[i] != ':'))
101 		break;
102 	    line[i++] = 0;
103 	}
104 	if (k < 4) {
105 	    warnx("%s: line %d: missing field(s)", gfn, n);
106 	    e++;
107 	    continue;
108 	}
109 
110 	/* check if fourth field ended with a colon */
111 	if (i < len) {
112 	    warnx("%s: line %d: too many fields", gfn, n);
113 	    e++;
114 	    continue;
115 	}
116 
117 	/* check that none of the fields contain whitespace */
118 	for (k = 0; k < 4; k++)
119 	    if (strcspn(f[k], " \t") != strlen(f[k]))
120 		warnx("%s: line %d: field %d contains whitespace",
121 		      gfn, n, k+1);
122 
123 	/* check that the GID is numeric */
124 	if (strspn(f[2], "0123456789") != strlen(f[2])) {
125 	    warnx("%s: line %d: GID is not numeric", gfn, n);
126 	    e++;
127 	    continue;
128 	}
129 
130 #if 0
131 	/* entry is correct, so print it */
132 	printf("%s:%s:%s:%s\n", f[0], f[1], f[2], f[3]);
133 #endif
134     }
135 
136     /* check what broke the loop */
137     if (ferror(gf))
138 	err(EX_IOERR, "%s: line %d", gfn, n);
139 
140     /* done */
141     fclose(gf);
142     exit(e ? EX_DATAERR : EX_OK);
143 }
144