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 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 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