bin/sh/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  * 3. 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 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD$");
  40
  41 /*
  42  * String functions.
  43  *
  44  *      equal(s1, s2)           Return true if strings are equal.
  45  *      number(s)               Convert a string of digits to an integer.
  46  *      is_number(s)            Return true if s is a string of digits.
  47  */
  48
  49 #include <stdlib.h>
  50 #include "shell.h"
  51 #include "syntax.h"
  52 #include "error.h"
  53 #include "mystring.h"
  54
  55
  56 char nullstr[1];                /* zero length string */
  57
  58 /*
  59  * equal - #defined in mystring.h
  60  */
  61
  62
  63 /*
  64  * Convert a string of digits to an integer, printing an error message on
  65  * failure.
  66  */
  67
  68 int
  69 number(const char *s)
  70 {
  71         if (! is_number(s))
  72                 error("Illegal number: %s", s);
  73         return atoi(s);
  74 }
  75
  76
  77
  78 /*
  79  * Check for a valid number.  This should be elsewhere.
  80  */
  81
  82 int
  83 is_number(const char *p)
  84 {
  85         const char *q;
  86
  87         if (*p == '\0')
  88                 return 0;
  89         while (*p == '0')
  90                 p++;
  91         for (q = p; *q != '\0'; q++)
  92                 if (! is_digit(*q))
  93                         return 0;
  94         if (q - p > 10 ||
  95             (q - p == 10 && memcmp(p, "2147483647", 10) > 0))
  96                         return 0;
  97         return 1;
  98 }