1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)mystring.c 8.2 (Berkeley) 5/4/95 33 * $FreeBSD: head/bin/sh/mystring.c 229219 2012-01-01 22:15:38Z jilles $ 34 */ 35 36 /* 37 * String functions. 38 * 39 * equal(s1, s2) Return true if strings are equal. 40 * scopy(from, to) Copy a string. 41 * number(s) Convert a string of digits to an integer. 42 * is_number(s) Return true if s is a string of digits. 43 */ 44 45 #include <stdlib.h> 46 #include "shell.h" 47 #include "syntax.h" 48 #include "error.h" 49 #include "mystring.h" 50 51 52 char nullstr[1]; /* zero length string */ 53 54 /* 55 * equal - #defined in mystring.h 56 */ 57 58 /* 59 * scopy - #defined in mystring.h 60 */ 61 62 63 /* 64 * prefix -- see if pfx is a prefix of string. 65 */ 66 67 int 68 prefix(const char *pfx, const char *string) 69 { 70 while (*pfx) { 71 if (*pfx++ != *string++) 72 return 0; 73 } 74 return 1; 75 } 76 77 78 /* 79 * Convert a string of digits to an integer, printing an error message on 80 * failure. 81 */ 82 83 int 84 number(const char *s) 85 { 86 if (! is_number(s)) 87 error("Illegal number: %s", s); 88 return atoi(s); 89 } 90 91 92 93 /* 94 * Check for a valid number. This should be elsewhere. 95 */ 96 97 int 98 is_number(const char *p) 99 { 100 do { 101 if (! is_digit(*p)) 102 return 0; 103 } while (*++p != '\0'); 104 return 1; 105 } 106