chkgrp.c revision 61019 
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 without 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
29#ifndef lint
30static const char rcsid[] =
31  "$FreeBSD: head/usr.sbin/chkgrp/chkgrp.c 61019 2000-05-28 14:57:49Z charnier $";
32#endif /* not lint */
33
34#include <err.h>
35#include <ctype.h>
36#include <stdio.h>
37#include <string.h>
38#include <sysexits.h>
39
40void
41usage(void)
42{
43    fprintf(stderr, "usage: chkgrp [groupfile]\n");
44    exit(EX_USAGE);
45}
46
47int
48main(int argc, char *argv[])
49{
50    unsigned int len;
51    int n = 0, i, k, e = 0;
52    char *gfn, *line, *f[4], *p;
53    FILE *gf;
54
55    /* check arguments */
56    switch (argc) {
57    case 1:
58	gfn = "/etc/group";
59	break;
60    case 2:
61	gfn = argv[1];
62	break;
63    default:
64	gfn = NULL; /* silence compiler */
65	usage();
66    }
67
68    /* open group file */
69    if ((gf = fopen(gfn, "r")) == NULL)
70	err(EX_IOERR, "%s", gfn); /* XXX - is IO_ERR the correct exit code? */
71
72    /* check line by line */
73    while (++n) {
74	if ((line = fgetln(gf, &len)) == NULL)
75	    break;
76	while (len && isspace(line[len-1]))
77	    len--;
78
79	/* ignore blank lines and comments */
80	for (p = line; p < (line + len); p++)
81	    if (!isspace(*p)) break;
82	if (!len || (*p == '#')) {
83#if 0
84	    /* entry is correct, so print it */
85	    printf("%*.*s\n", len, len, line);
86#endif
87	    continue;
88	}
89
90	/*
91	 * A correct group entry has four colon-separated fields, the third
92	 * of which must be entirely numeric and the fourth of which may
93	 * be empty.
94	 */
95	for (i = k = 0; k < 4; k++) {
96	    for (f[k] = line+i; (i < len) && (line[i] != ':'); i++)
97		/* nothing */ ;
98	    if ((k < 3) && (line[i] != ':'))
99		break;
100	    line[i++] = 0;
101	}
102	if (k < 4) {
103	    warnx("%s: line %d: missing field(s)", gfn, n);
104	    e++;
105	    continue;
106	}
107
108	/* check if fourth field ended with a colon */
109	if (i < len) {
110	    warnx("%s: line %d: too many fields", gfn, n);
111	    e++;
112	    continue;
113	}
114
115	/* check that none of the fields contain whitespace */
116	for (k = 0; k < 4; k++)
117	    if (strcspn(f[k], " \t") != strlen(f[k]))
118		warnx("%s: line %d: field %d contains whitespace",
119		      gfn, n, k+1);
120
121	/* check that the GID is numeric */
122	if (strspn(f[2], "0123456789") != strlen(f[2])) {
123	    warnx("%s: line %d: GID is not numeric", gfn, n);
124	    e++;
125	    continue;
126	}
127
128#if 0
129	/* entry is correct, so print it */
130	printf("%s:%s:%s:%s\n", f[0], f[1], f[2], f[3]);
131#endif
132    }
133
134    /* check what broke the loop */
135    if (ferror(gf))
136	err(EX_IOERR, "%s: line %d", gfn, n);
137
138    /* done */
139    fclose(gf);
140    exit(e ? EX_DATAERR : EX_OK);
141}
142