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 * $Id$ 37 */ 38 39 #ifndef lint 40 static char sccsid[] = "@(#)mystring.c 8.1 (Berkeley) 5/31/93"; 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 "shell.h" 54 #include "syntax.h" 55 #include "error.h" 56 #include "mystring.h" 57 58 59 char nullstr[1]; /* zero length string */ 60 61 /* 62 * equal - #defined in mystring.h 63 */ 64 65 /* 66 * scopy - #defined in mystring.h 67 */ 68 69 70 /* 71 * scopyn - copy a string from "from" to "to", truncating the string 72 * if necessary. "To" is always nul terminated, even if 73 * truncation is performed. "Size" is the size of "to". 74 */ 75 76 void 77 scopyn(from, to, size) 78 register char const *from; 79 register char *to; 80 register int size; 81 { 82 83 while (--size > 0) { 84 if ((*to++ = *from++) == '\0') 85 return; 86 } 87 *to = '\0'; 88 } 89 90 91 /* 92 * prefix -- see if pfx is a prefix of string. 93 */ 94 95 int 96 prefix(pfx, string) 97 register char const *pfx; 98 register char const *string; 99 { 100 while (*pfx) { 101 if (*pfx++ != *string++) 102 return 0; 103 } 104 return 1; 105 } 106 107 108 /* 109 * Convert a string of digits to an integer, printing an error message on 110 * failure. 111 */ 112 113 int 114 number(s) 115 const char *s; 116 { 117 118 if (! is_number(s)) 119 error2("Illegal number", (char *)s); 120 return atoi(s); 121 } 122 123 124 125 /* 126 * Check for a valid number. This should be elsewhere. 127 */ 128 129 int 130 is_number(p) 131 register const char *p; 132 { 133 do { 134 if (! is_digit(*p)) 135 return 0; 136 } while (*++p != '\0'); 137 return 1; 138 } 139