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