xref: /netbsd-src/bin/sh/mystring.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: mystring.c,v 1.18 2018/07/13 22:43:44 kre 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 1.18 2018/07/13 22:43:44 kre 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 <inttypes.h>
55 #include <limits.h>
56 #include <stdlib.h>
57 #include "shell.h"
58 #include "syntax.h"
59 #include "error.h"
60 #include "mystring.h"
61 
62 
63 const char nullstr[1];		/* zero length string */
64 
65 /*
66  * equal - #defined in mystring.h
67  */
68 
69 /*
70  * scopy - #defined in mystring.h
71  */
72 
73 
74 /*
75  * scopyn - copy a string from "from" to "to", truncating the string
76  *		if necessary.  "To" is always nul terminated, even if
77  *		truncation is performed.  "Size" is the size of "to".
78  */
79 
80 void
81 scopyn(const char *from, char *to, int size)
82 {
83 
84 	while (--size > 0) {
85 		if ((*to++ = *from++) == '\0')
86 			return;
87 	}
88 	*to = '\0';
89 }
90 
91 
92 /*
93  * prefix -- see if pfx is a prefix of string.
94  */
95 
96 int
97 prefix(const char *pfx, const char *string)
98 {
99 	while (*pfx) {
100 		if (*pfx++ != *string++)
101 			return 0;
102 	}
103 	return 1;
104 }
105 
106 
107 /*
108  * Convert a string of digits to an integer, printing an error message on
109  * failure.
110  */
111 
112 int
113 number(const char *s)
114 {
115 	char *ep = NULL;
116 	intmax_t n;
117 
118 	if (!is_digit(*s) || ((n = strtoimax(s, &ep, 10)),
119 	    (ep == NULL || ep == s || *ep != '\0')))
120 		error("Illegal number: '%s'", s);
121 	if (n < INT_MIN || n > INT_MAX)
122 		error("Number out of range: %s", s);
123 	return (int)n;
124 }
125 
126 
127 
128 /*
129  * Check for a valid number.  This should be elsewhere.
130  */
131 
132 int
133 is_number(const char *p)
134 {
135 	do {
136 		if (! is_digit(*p))
137 			return 0;
138 	} while (*++p != '\0');
139 	return 1;
140 }
141