bin/sh/mystring.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   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 #ifndef lint
  36 #if 0
  37 static char sccsid[] = "@(#)mystring.c  8.2 (Berkeley) 5/4/95";
  38 #endif
  39 #endif /* not lint */
  40 #include <sys/cdefs.h>
  41 __FBSDID("$FreeBSD: head/bin/sh/mystring.c 326025 2017-11-20 19:49:47Z pfg $");
  42
  43 /*
  44  * String functions.
  45  *
  46  *      equal(s1, s2)           Return true if strings are equal.
  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 <stdlib.h>
  52 #include "shell.h"
  53 #include "syntax.h"
  54 #include "error.h"
  55 #include "mystring.h"
  56
  57
  58 char nullstr[1];                /* zero length string */
  59
  60 /*
  61  * equal - #defined in mystring.h
  62  */
  63
  64
  65 /*
  66  * Convert a string of digits to an integer, printing an error message on
  67  * failure.
  68  */
  69
  70 int
  71 number(const char *s)
  72 {
  73         if (! is_number(s))
  74                 error("Illegal number: %s", s);
  75         return atoi(s);
  76 }
  77
  78
  79
  80 /*
  81  * Check for a valid number.  This should be elsewhere.
  82  */
  83
  84 int
  85 is_number(const char *p)
  86 {
  87         const char *q;
  88
  89         if (*p == '\0')
  90                 return 0;
  91         while (*p == '0')
  92                 p++;
  93         for (q = p; *q != '\0'; q++)
  94                 if (! is_digit(*q))
  95                         return 0;
  96         if (q - p > 10 ||
  97             (q - p == 10 && memcmp(p, "2147483647", 10) > 0))
  98                 return 0;
  99         return 1;
 100 }