Home | History | Annotate | Line # | Download | only in sh
mystring.c revision 1.14 
      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