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 "shell.h" 52 #include "syntax.h" 53 #include "error.h" 54 #include "mystring.h" 55 56 57 char nullstr[1]; /* zero length string */ 58 59 /* 60 * equal - #defined in mystring.h 61 */ 62 63 /* 64 * scopy - #defined in mystring.h 65 */ 66 67 68 /* 69 * scopyn - copy a string from "from" to "to", truncating the string 70 * if necessary. "To" is always nul terminated, even if 71 * truncation is performed. "Size" is the size of "to". 72 */ 73 74 void 75 scopyn(from, to, size) 76 register char const *from; 77 register char *to; 78 register int size; 79 { 80 81 while (--size > 0) { 82 if ((*to++ = *from++) == '\0') 83 return; 84 } 85 *to = '\0'; 86 } 87 88 89 /* 90 * prefix -- see if pfx is a prefix of string. 91 */ 92 93 int 94 prefix(pfx, string) 95 register char const *pfx; 96 register char const *string; 97 { 98 while (*pfx) { 99 if (*pfx++ != *string++) 100 return 0; 101 } 102 return 1; 103 } 104 105 106 /* 107 * Convert a string of digits to an integer, printing an error message on 108 * failure. 109 */ 110 111 int 112 number(s) 113 const char *s; 114 { 115 116 if (! is_number(s)) 117 error2("Illegal number", (char *)s); 118 return atoi(s); 119 } 120 121 122 123 /* 124 * Check for a valid number. This should be elsewhere. 125 */ 126 127 int 128 is_number(p) 129 register const char *p; 130 { 131 do { 132 if (! is_digit(*p)) 133 return 0; 134 } while (*++p != '\0'); 135 return 1; 136 } 137