commands/ash/mystring.c

   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  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)mystring.c  8.2 (Berkeley) 5/4/95";
  36 #endif
  37 #endif /* not lint */
  38 /*
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD: src/bin/sh/mystring.c,v 1.13 2004/04/06 20:06:51 markm Exp $");
  41 */
  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(const char *from, char *to, 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(const char *pfx, const char *string)
  95 {
  96         while (*pfx) {
  97                 if (*pfx++ != *string++)
  98                         return 0;
  99         }
 100         return 1;
 101 }
 102
 103
 104 /*
 105  * Convert a string of digits to an integer, printing an error message on
 106  * failure.
 107  */
 108
 109 int
 110 number(const char *s)
 111 {
 112         if (! is_number(s))
 113                 error("Illegal number: %s", (char *)s);
 114         return atoi(s);
 115 }
 116
 117
 118
 119 /*
 120  * Check for a valid number.  This should be elsewhere.
 121  */
 122
 123 int
 124 is_number(const char *p)
 125 {
 126         do {
 127                 if (! is_digit(*p))
 128                         return 0;
 129         } while (*++p != '\0');
 130         return 1;
 131 }
 132
 133 /*
 134  * $PchId: mystring.c,v 1.4 2006/05/22 12:21:53 philip Exp $
 135  */