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 37 #ifndef lint 38 static char sccsid[] = "@(#)mystring.c 8.1 (Berkeley) 5/31/93"; 39 #endif /* not lint */ 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(from, to, size) 77 register char const *from; 78 register char *to; 79 register 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(pfx, string) 96 register char const *pfx; 97 register char const *string; 98 { 99 while (*pfx) { 100 if (*pfx++ != *string++) 101 return 0; 102 } 103 return 1; 104 } 105 106 107 /* 108 * Convert a string of digits to an integer, printing an error message on 109 * failure. 110 */ 111 112 int 113 number(s) 114 const char *s; 115 { 116 117 if (! is_number(s)) 118 error2("Illegal number", (char *)s); 119 return atoi(s); 120 } 121 122 123 124 /* 125 * Check for a valid number. This should be elsewhere. 126 */ 127 128 int 129 is_number(p) 130 register const char *p; 131 { 132 do { 133 if (! is_digit(*p)) 134 return 0; 135 } while (*++p != '\0'); 136 return 1; 137 } 138