src/kash/mystring.c

   1 /*      $NetBSD: mystring.c,v 1.16 2003/08/07 09:05:35 agc Exp $        */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Kenneth Almquist.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #if 0
  36 #ifndef lint
  37 static char sccsid[] = "@(#)mystring.c  8.2 (Berkeley) 5/4/95";
  38 #else
  39 __RCSID("$NetBSD: mystring.c,v 1.16 2003/08/07 09:05:35 agc Exp $");
  40 #endif /* not lint */
  41 #endif
  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, ssize_t 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(shinstance *psh, const char *s)
 111 {
 112
 113         if (! is_number(s))
 114                 error(psh, "Illegal number: %s", s);
 115         return atoi(s);
 116 }
 117
 118
 119
 120 /*
 121  * Check for a valid number.  This should be elsewhere.
 122  */
 123
 124 int
 125 is_number(const char *p)
 126 {
 127         do {
 128                 if (! is_digit(*p))
 129                         return 0;
 130         } while (*++p != '\0');
 131         return 1;
 132 }