1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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/*
36 * String functions.
37 *
38 *	equal(s1, s2)		Return true if strings are equal.
39 *	number(s)		Convert a string of digits to an integer.
40 *	is_number(s)		Return true if s is a string of digits.
41 */
42
43#include <stdlib.h>
44#include "shell.h"
45#include "syntax.h"
46#include "error.h"
47#include "mystring.h"
48
49
50char nullstr[1];		/* zero length string */
51
52/*
53 * equal - #defined in mystring.h
54 */
55
56
57/*
58 * Convert a string of digits to an integer, printing an error message on
59 * failure.
60 */
61
62int
63number(const char *s)
64{
65	if (! is_number(s))
66		error("Illegal number: %s", s);
67	return atoi(s);
68}
69
70
71
72/*
73 * Check for a valid number.  This should be elsewhere.
74 */
75
76int
77is_number(const char *p)
78{
79	const char *q;
80
81	if (*p == '\0')
82		return 0;
83	while (*p == '0')
84		p++;
85	for (q = p; *q != '\0'; q++)
86		if (! is_digit(*q))
87			return 0;
88	if (q - p > 10 ||
89	    (q - p == 10 && memcmp(p, "2147483647", 10) > 0))
90		return 0;
91	return 1;
92}
93