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
50 char 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
62 int
number(const char * s)63 number(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
76 int
is_number(const char * p)77 is_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