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 * 4. 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 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)mystring.c 8.2 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 /* 42 * String functions. 43 * 44 * equal(s1, s2) Return true if strings are equal. 45 * scopy(from, to) Copy a string. 46 * scopyn(from, to, n) Like scopy, but checks for overflow. 47 * number(s) Convert a string of digits to an integer. 48 * is_number(s) Return true if s is a string of digits. 49 */ 50 51 #include <stdlib.h> 52 #include "shell.h" 53 #include "syntax.h" 54 #include "error.h" 55 #include "mystring.h" 56 57 58 char nullstr[1]; /* zero length string */ 59 60 /* 61 * equal - #defined in mystring.h 62 */ 63 64 /* 65 * scopy - #defined in mystring.h 66 */ 67 68 69 /* 70 * scopyn - copy a string from "from" to "to", truncating the string 71 * if necessary. "To" is always nul terminated, even if 72 * truncation is performed. "Size" is the size of "to". 73 */ 74 75 void 76 scopyn(const char *from, char *to, int size) 77 { 78 79 while (--size > 0) { 80 if ((*to++ = *from++) == '\0') 81 return; 82 } 83 *to = '\0'; 84 } 85 86 87 /* 88 * prefix -- see if pfx is a prefix of string. 89 */ 90 91 int 92 prefix(const char *pfx, const char *string) 93 { 94 while (*pfx) { 95 if (*pfx++ != *string++) 96 return 0; 97 } 98 return 1; 99 } 100 101 102 /* 103 * Convert a string of digits to an integer, printing an error message on 104 * failure. 105 */ 106 107 int 108 number(const char *s) 109 { 110 if (! is_number(s)) 111 error("Illegal number: %s", (char *)s); 112 return atoi(s); 113 } 114 115 116 117 /* 118 * Check for a valid number. This should be elsewhere. 119 */ 120 121 int 122 is_number(const char *p) 123 { 124 do { 125 if (! is_digit(*p)) 126 return 0; 127 } while (*++p != '\0'); 128 return 1; 129 } 130