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  1. /*  $NetBSD: mystring.c,v 1.14 1999/07/09 03:05:50 christos 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. All advertising materials mentioning features or use of this software
  19.  *    must display the following acknowledgement:
  20.  *  This product includes software developed by the University of
  21.  *  California, Berkeley and its contributors.
  22.  * 4. Neither the name of the University nor the names of its contributors
  23.  *    may be used to endorse or promote products derived from this software
  24.  *    without specific prior written permission.
  25.  *
  26.  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27.  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28.  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29.  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30.  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31.  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32.  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33.  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34.  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35.  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36.  * SUCH DAMAGE.
  37.  */
  38.  
  39. #include <sys/cdefs.h>
  40. #ifndef lint
  41. #if 0
  42. static char sccsid[] = "@(#)mystring.c  8.2 (Berkeley) 5/4/95";
  43. #else
  44. __RCSID("$NetBSD: mystring.c,v 1.14 1999/07/09 03:05:50 christos Exp $");
  45. #endif
  46. #endif /* not lint */
  47.  
  48. /*
  49.  * String functions.
  50.  *
  51.  *  equal(s1, s2)       Return true if strings are equal.
  52.  *  scopy(from, to)     Copy a string.
  53.  *  scopyn(from, to, n) Like scopy, but checks for overflow.
  54.  *  number(s)       Convert a string of digits to an integer.
  55.  *  is_number(s)        Return true if s is a string of digits.
  56.  */
  57.  
  58. #include <stdlib.h>
  59. #include "shell.h"
  60. #include "syntax.h"
  61. #include "error.h"
  62. #include "mystring.h"
  63.  
  64.  
  65. char nullstr[1];        /* zero length string */
  66.  
  67. /*
  68.  * equal - #defined in mystring.h
  69.  */
  70.  
  71. /*
  72.  * scopy - #defined in mystring.h
  73.  */
  74.  
  75.  
  76. /*
  77.  * scopyn - copy a string from "from" to "to", truncating the string
  78.  *      if necessary.  "To" is always nul terminated, even if
  79.  *      truncation is performed.  "Size" is the size of "to".
  80.  */
  81.  
  82. void
  83. scopyn(from, to, size)
  84.     char const *from;
  85.     char *to;
  86.     int size;
  87.     {
  88.  
  89.     while (--size > 0) {
  90.         if ((*to++ = *from++) == '\0')
  91.             return;
  92.     }
  93.     *to = '\0';
  94. }
  95.  
  96.  
  97. /*
  98.  * prefix -- see if pfx is a prefix of string.
  99.  */
  100.  
  101. int
  102. prefix(pfx, string)
  103.     char const *pfx;
  104.     char const *string;
  105.     {
  106.     while (*pfx) {
  107.         if (*pfx++ != *string++)
  108.             return 0;
  109.     }
  110.     return 1;
  111. }
  112.  
  113.  
  114. /*
  115.  * Convert a string of digits to an integer, printing an error message on
  116.  * failure.
  117.  */
  118.  
  119. int
  120. number(s)
  121.     const char *s;
  122.     {
  123.  
  124.     if (! is_number(s))
  125.         error("Illegal number: %s", s);
  126.     return atoi(s);
  127. }
  128.  
  129.  
  130.  
  131. /*
  132.  * Check for a valid number.  This should be elsewhere.
  133.  */
  134.  
  135. int
  136. is_number(p)
  137.     const char *p;
  138.     {
  139.     do {
  140.         if (! is_digit(*p))
  141.             return 0;
  142.     } while (*++p != '\0');
  143.     return 1;
  144. }
  145.