1 /* $NetBSD: mystring.c,v 1.16 2003/08/07 09:05:35 agc Exp $ */ 2 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 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)mystring.c 8.2 (Berkeley) 5/4/95"; 39 #else 40 __RCSID("$NetBSD: mystring.c,v 1.16 2003/08/07 09:05:35 agc Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 /* 45 * String functions. 46 * 47 * equal(s1, s2) Return true if strings are equal. 48 * scopy(from, to) Copy a string. 49 * scopyn(from, to, n) Like scopy, but checks for overflow. 50 * number(s) Convert a string of digits to an integer. 51 * is_number(s) Return true if s is a string of digits. 52 */ 53 54 #include <stdlib.h> 55 #include "shell.h" 56 #include "syntax.h" 57 #include "error.h" 58 #include "mystring.h" 59 60 61 char nullstr[1]; /* zero length string */ 62 63 /* 64 * equal - #defined in mystring.h 65 */ 66 67 /* 68 * scopy - #defined in mystring.h 69 */ 70 71 72 /* 73 * scopyn - copy a string from "from" to "to", truncating the string 74 * if necessary. "To" is always nul terminated, even if 75 * truncation is performed. "Size" is the size of "to". 76 */ 77 78 void 79 scopyn(const char *from, char *to, int size) 80 { 81 82 while (--size > 0) { 83 if ((*to++ = *from++) == '\0') 84 return; 85 } 86 *to = '\0'; 87 } 88 89 90 /* 91 * prefix -- see if pfx is a prefix of string. 92 */ 93 94 int 95 prefix(const char *pfx, const char *string) 96 { 97 while (*pfx) { 98 if (*pfx++ != *string++) 99 return 0; 100 } 101 return 1; 102 } 103 104 105 /* 106 * Convert a string of digits to an integer, printing an error message on 107 * failure. 108 */ 109 110 int 111 number(const char *s) 112 { 113 114 if (! is_number(s)) 115 error("Illegal number: %s", s); 116 return atoi(s); 117 } 118 119 120 121 /* 122 * Check for a valid number. This should be elsewhere. 123 */ 124 125 int 126 is_number(const char *p) 127 { 128 do { 129 if (! is_digit(*p)) 130 return 0; 131 } while (*++p != '\0'); 132 return 1; 133 } 134