chkgrp.c revision 115891 
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#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/usr.sbin/chkgrp/chkgrp.c 115891 2003-06-06 07:10:39Z roam $");
31
32#include <err.h>
33#include <ctype.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <sysexits.h>
38
39static void
40usage(void)
41{
42    fprintf(stderr, "usage: chkgrp [groupfile]\n");
43    exit(EX_USAGE);
44}
45
46int
47main(int argc, char *argv[])
48{
49    unsigned int i;
50    size_t len;
51    int n = 0, k, e = 0;
52    char *line, *f[4], *p;
53    const char *gfn;
54    FILE *gf;
55
56    /* check arguments */
57    switch (argc) {
58    case 1:
59	gfn = "/etc/group";
60	break;
61    case 2:
62	gfn = argv[1];
63	break;
64    default:
65	gfn = NULL; /* silence compiler */
66	usage();
67    }
68
69    /* open group file */
70    if ((gf = fopen(gfn, "r")) == NULL)
71	err(EX_IOERR, "%s", gfn); /* XXX - is IO_ERR the correct exit code? */
72
73    /* check line by line */
74    while (++n) {
75	if ((line = fgetln(gf, &len)) == NULL)
76	    break;
77	if (len > 0 && line[len - 1] != '\n') {
78	    warnx("%s: line %d: no newline character", gfn, n);
79	    e++;
80	}
81	while (len && isspace(line[len-1]))
82	    len--;
83
84	/* ignore blank lines and comments */
85	for (p = line; p < (line + len); p++)
86	    if (!isspace(*p)) break;
87	if (!len || (*p == '#')) {
88#if 0
89	    /* entry is correct, so print it */
90	    printf("%*.*s\n", len, len, line);
91#endif
92	    continue;
93	}
94
95	/*
96	 * A correct group entry has four colon-separated fields, the third
97	 * of which must be entirely numeric and the fourth of which may
98	 * be empty.
99	 */
100	for (i = k = 0; k < 4; k++) {
101	    for (f[k] = line+i; (i < len) && (line[i] != ':'); i++)
102		/* nothing */ ;
103	    if ((k < 3) && (line[i] != ':'))
104		break;
105	    line[i++] = 0;
106	}
107	if (k < 4) {
108	    warnx("%s: line %d: missing field(s)", gfn, n);
109	    e++;
110	    continue;
111	}
112
113	/* check if fourth field ended with a colon */
114	if (i < len) {
115	    warnx("%s: line %d: too many fields", gfn, n);
116	    e++;
117	    continue;
118	}
119
120	/* check that none of the fields contain whitespace */
121	for (k = 0; k < 4; k++)
122	    if (strcspn(f[k], " \t") != strlen(f[k]))
123		warnx("%s: line %d: field %d contains whitespace",
124		      gfn, n, k+1);
125
126	/* check that the GID is numeric */
127	if (strspn(f[2], "0123456789") != strlen(f[2])) {
128	    warnx("%s: line %d: GID is not numeric", gfn, n);
129	    e++;
130	    continue;
131	}
132
133#if 0
134	/* entry is correct, so print it */
135	printf("%s:%s:%s:%s\n", f[0], f[1], f[2], f[3]);
136#endif
137    }
138
139    /* check what broke the loop */
140    if (ferror(gf))
141	err(EX_IOERR, "%s: line %d", gfn, n);
142
143    /* done */
144    fclose(gf);
145    exit(e ? EX_DATAERR : EX_OK);
146}
147