1 /* $NetBSD: mystring.c,v 1.17 2013/04/28 17:01:28 dholland Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)mystring.c 8.2 (Berkeley) 5/4/95";
39 #else
40 __RCSID("$NetBSD: mystring.c,v 1.17 2013/04/28 17:01:28 dholland Exp $");
41 #endif
42 #endif /* not lint */
43
44 /*
45 * String functions.
46 *
47 * equal(s1, s2) Return true if strings are equal.
48 * scopy(from, to) Copy a string.
49 * scopyn(from, to, n) Like scopy, but checks for overflow.
50 * number(s) Convert a string of digits to an integer.
51 * is_number(s) Return true if s is a string of digits.
52 */
53
54 #include <stdlib.h>
55 #include "shell.h"
56 #include "syntax.h"
57 #include "error.h"
58 #include "mystring.h"
59
60
61 const char nullstr[1]; /* zero length string */
62
63 /*
64 * equal - #defined in mystring.h
65 */
66
67 /*
68 * scopy - #defined in mystring.h
69 */
70
71
72 /*
73 * scopyn - copy a string from "from" to "to", truncating the string
74 * if necessary. "To" is always nul terminated, even if
75 * truncation is performed. "Size" is the size of "to".
76 */
77
78 void
scopyn(const char * from,char * to,int size)79 scopyn(const char *from, char *to, int size)
80 {
81
82 while (--size > 0) {
83 if ((*to++ = *from++) == '\0')
84 return;
85 }
86 *to = '\0';
87 }
88
89
90 /*
91 * prefix -- see if pfx is a prefix of string.
92 */
93
94 int
prefix(const char * pfx,const char * string)95 prefix(const char *pfx, const char *string)
96 {
97 while (*pfx) {
98 if (*pfx++ != *string++)
99 return 0;
100 }
101 return 1;
102 }
103
104
105 /*
106 * Convert a string of digits to an integer, printing an error message on
107 * failure.
108 */
109
110 int
number(const char * s)111 number(const char *s)
112 {
113
114 if (! is_number(s))
115 error("Illegal number: %s", s);
116 return atoi(s);
117 }
118
119
120
121 /*
122 * Check for a valid number. This should be elsewhere.
123 */
124
125 int
is_number(const char * p)126 is_number(const char *p)
127 {
128 do {
129 if (! is_digit(*p))
130 return 0;
131 } while (*++p != '\0');
132 return 1;
133 }
134