1/*	$NetBSD: mystring.c,v 1.16 2003/08/07 09:05:35 agc 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
38static char sccsid[] = "@(#)mystring.c	8.2 (Berkeley) 5/4/95";
39#else
40__RCSID("$NetBSD: mystring.c,v 1.16 2003/08/07 09:05:35 agc 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
61char 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
78void
79scopyn(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
94int
95prefix(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
110int
111number(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
125int
126is_number(const char *p)
127{
128	do {
129		if (! is_digit(*p))
130			return 0;
131	} while (*++p != '\0');
132	return 1;
133}
134