1 /*- 2 * Copyright (c) 1991 The Regents of the University of California. 3 * 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 5.1 (Berkeley) 3/7/91"; 39 static char rcsid[] = "$Header: /cvsroot/src/bin/sh/mystring.c,v 1.3 1993/03/23 00:28:50 cgd Exp $"; 40 #endif /* not lint */ 41 42 /* 43 * String functions. 44 * 45 * equal(s1, s2) Return true if strings are equal. 46 * scopy(from, to) Copy a string. 47 * scopyn(from, to, n) Like scopy, but checks for overflow. 48 * strchr(s, c) Find first occurance of c in s. 49 * bcopy(from, to, n) Copy a block of memory. 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 "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 /* 64 * scopyn - copy a string from "from" to "to", truncating the string 65 * if necessary. "To" is always nul terminated, even if 66 * truncation is performed. "Size" is the size of "to". 67 */ 68 69 void 70 scopyn(from, to, size) 71 register char const *from; 72 register char *to; 73 register int size; 74 { 75 76 while (--size > 0) { 77 if ((*to++ = *from++) == '\0') 78 return; 79 } 80 *to = '\0'; 81 } 82 83 84 /* 85 * strchr - find first occurrence of a character in a string. 86 */ 87 88 #ifndef SYS5 89 char * 90 mystrchr(s, charwanted) 91 char const *s; 92 register char charwanted; 93 { 94 register char const *scan; 95 96 /* 97 * The odd placement of the two tests is so NUL is findable. 98 */ 99 for (scan = s ; *scan != charwanted ; ) /* ++ moved down for opt. */ 100 if (*scan++ == '\0') 101 return NULL; 102 return (char *)scan; 103 } 104 #endif 105 106 107 108 /* 109 * bcopy - copy bytes 110 * 111 * This routine was derived from code by Henry Spencer. 112 */ 113 114 void 115 mybcopy(src, dst, length) 116 pointer dst; 117 const pointer src; 118 register int length; 119 { 120 register char *d = dst; 121 register char *s = src; 122 123 while (--length >= 0) 124 *d++ = *s++; 125 } 126 127 128 /* 129 * prefix -- see if pfx is a prefix of string. 130 */ 131 132 int 133 prefix(pfx, string) 134 register char const *pfx; 135 register char const *string; 136 { 137 while (*pfx) { 138 if (*pfx++ != *string++) 139 return 0; 140 } 141 return 1; 142 } 143 144 145 /* 146 * Convert a string of digits to an integer, printing an error message on 147 * failure. 148 */ 149 150 int 151 number(s) 152 const char *s; 153 { 154 155 if (! is_number(s)) 156 error2("Illegal number", (char *)s); 157 return atoi(s); 158 } 159 160 161 162 /* 163 * Check for a valid number. This should be elsewhere. 164 */ 165 166 int 167 is_number(p) 168 register const char *p; 169 { 170 do { 171 if (! is_digit(*p)) 172 return 0; 173 } while (*++p != '\0'); 174 return 1; 175 } 176