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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $Id: mystring.c,v 1.7 1997/02/22 13:58:38 peter Exp $ 37 */ 38 39 #ifndef lint 40 static char const sccsid[] = "@(#)mystring.c 8.2 (Berkeley) 5/4/95"; 41 #endif /* not lint */ 42 43 /* 44 * String functions. 45 * 46 * equal(s1, s2) Return true if strings are equal. 47 * scopy(from, to) Copy a string. 48 * scopyn(from, to, n) Like scopy, but checks for overflow. 49 * number(s) Convert a string of digits to an integer. 50 * is_number(s) Return true if s is a string of digits. 51 */ 52 53 #include <stdlib.h> 54 #include "shell.h" 55 #include "syntax.h" 56 #include "error.h" 57 #include "mystring.h" 58 59 60 char nullstr[1]; /* zero length string */ 61 62 /* 63 * equal - #defined in mystring.h 64 */ 65 66 /* 67 * scopy - #defined in mystring.h 68 */ 69 70 71 /* 72 * scopyn - copy a string from "from" to "to", truncating the string 73 * if necessary. "To" is always nul terminated, even if 74 * truncation is performed. "Size" is the size of "to". 75 */ 76 77 void 78 scopyn(from, to, size) 79 char const *from; 80 char *to; 81 int size; 82 { 83 84 while (--size > 0) { 85 if ((*to++ = *from++) == '\0') 86 return; 87 } 88 *to = '\0'; 89 } 90 91 92 /* 93 * prefix -- see if pfx is a prefix of string. 94 */ 95 96 int 97 prefix(pfx, string) 98 char const *pfx; 99 char const *string; 100 { 101 while (*pfx) { 102 if (*pfx++ != *string++) 103 return 0; 104 } 105 return 1; 106 } 107 108 109 /* 110 * Convert a string of digits to an integer, printing an error message on 111 * failure. 112 */ 113 114 int 115 number(s) 116 const char *s; 117 { 118 119 if (! is_number(s)) 120 error("Illegal number: %s", (char *)s); 121 return atoi(s); 122 } 123 124 125 126 /* 127 * Check for a valid number. This should be elsewhere. 128 */ 129 130 int 131 is_number(p) 132 const char *p; 133 { 134 do { 135 if (! is_digit(*p)) 136 return 0; 137 } while (*++p != '\0'); 138 return 1; 139 } 140