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mystring.c revision 1.11 
      1 /*	$NetBSD: mystring.c,v 1.11 1996/10/16 14:49:03 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 #ifndef lint
     40 #if 0
     41 static char sccsid[] = "@(#)mystring.c	8.2 (Berkeley) 5/4/95";
     42 #else
     43 static char rcsid[] = "$NetBSD: mystring.c,v 1.11 1996/10/16 14:49:03 christos Exp $";
     44 #endif
     45 #endif /* not lint */
     46 
     47 /*
     48  * String functions.
     49  *
     50  *	equal(s1, s2)		Return true if strings are equal.
     51  *	scopy(from, to)		Copy a string.
     52  *	scopyn(from, to, n)	Like scopy, but checks for overflow.
     53  *	number(s)		Convert a string of digits to an integer.
     54  *	is_number(s)		Return true if s is a string of digits.
     55  */
     56 
     57 #include <stdlib.h>
     58 #include "shell.h"
     59 #include "syntax.h"
     60 #include "error.h"
     61 #include "mystring.h"
     62 
     63 
     64 char nullstr[1];		/* zero length string */
     65 
     66 /*
     67  * equal - #defined in mystring.h
     68  */
     69 
     70 /*
     71  * scopy - #defined in mystring.h
     72  */
     73 
     74 
     75 /*
     76  * scopyn - copy a string from "from" to "to", truncating the string
     77  *		if necessary.  "To" is always nul terminated, even if
     78  *		truncation is performed.  "Size" is the size of "to".
     79  */
     80 
     81 void
     82 scopyn(from, to, size)
     83 	register char const *from;
     84 	register char *to;
     85 	register int size;
     86 	{
     87 
     88 	while (--size > 0) {
     89 		if ((*to++ = *from++) == '\0')
     90 			return;
     91 	}
     92 	*to = '\0';
     93 }
     94 
     95 
     96 /*
     97  * prefix -- see if pfx is a prefix of string.
     98  */
     99 
    100 int
    101 prefix(pfx, string)
    102 	register char const *pfx;
    103 	register char const *string;
    104 	{
    105 	while (*pfx) {
    106 		if (*pfx++ != *string++)
    107 			return 0;
    108 	}
    109 	return 1;
    110 }
    111 
    112 
    113 /*
    114  * Convert a string of digits to an integer, printing an error message on
    115  * failure.
    116  */
    117 
    118 int
    119 number(s)
    120 	const char *s;
    121 	{
    122 
    123 	if (! is_number(s))
    124 		error("Illegal number: %s", (char *)s);
    125 	return atoi(s);
    126 }
    127 
    128 
    129 
    130 /*
    131  * Check for a valid number.  This should be elsewhere.
    132  */
    133 
    134 int
    135 is_number(p)
    136 	register const char *p;
    137 	{
    138 	do {
    139 		if (! is_digit(*p))
    140 			return 0;
    141 	} while (*++p != '\0');
    142 	return 1;
    143 }
    144