xref: /freebsd/usr.sbin/chkgrp/chkgrp.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
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
30 static const char rcsid[] =
31   "$FreeBSD$";
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 
40 void
41 usage(void)
42 {
43     fprintf(stderr, "usage: chkgrp [groupfile]\n");
44     exit(EX_USAGE);
45 }
46 
47 int
48 main(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, 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