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mystring.c revision 1.19 
      1 /*	$NetBSD: mystring.c,v 1.19 2022/04/16 14:20:45 kre 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. 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 #include <sys/cdefs.h>
     36 #ifndef lint
     37 #if 0
     38 static char sccsid[] = "@(#)mystring.c	8.2 (Berkeley) 5/4/95";
     39 #else
     40 __RCSID("$NetBSD: mystring.c,v 1.19 2022/04/16 14:20:45 kre Exp $");
     41 #endif
     42 #endif /* not lint */
     43 
     44 /*
     45  * String functions.
     46  *
     47  *	equal(s1, s2)		Return true if strings are equal.
     48  *	scopy(from, to)		Copy a string.
     49  *	scopyn(from, to, n)	Like scopy, but checks for overflow.
     50  *	number(s)		Convert a string of digits to an integer.
     51  *	is_number(s)		Return true if s is a string of digits.
     52  */
     53 
     54 #include <inttypes.h>
     55 #include <limits.h>
     56 #include <stdlib.h>
     57 #include "shell.h"
     58 #include "syntax.h"
     59 #include "error.h"
     60 #include "mystring.h"
     61 
     62 
     63 const char nullstr[1];		/* zero length string */
     64 
     65 /*
     66  * equal - #defined in mystring.h
     67  */
     68 
     69 /*
     70  * scopy - #defined in mystring.h
     71  */
     72 
     73 
     74 /*
     75  * scopyn - copy a string from "from" to "to", truncating the string
     76  *		if necessary.  "To" is always nul terminated, even if
     77  *		truncation is performed.  "Size" is the size of "to".
     78  */
     79 
     80 void
     81 scopyn(const char *from, char *to, int size)
     82 {
     83 
     84 	while (--size > 0) {
     85 		if ((*to++ = *from++) == '\0')
     86 			return;
     87 	}
     88 	*to = '\0';
     89 }
     90 
     91 
     92 /*
     93  * prefix -- see if pfx is a prefix of string.
     94  */
     95 
     96 int
     97 prefix(const char *pfx, const char *string)
     98 {
     99 	while (*pfx) {
    100 		if (*pfx++ != *string++)
    101 			return 0;
    102 	}
    103 	return 1;
    104 }
    105 
    106 
    107 /*
    108  * Convert a string of digits to an integer, printing an error message on
    109  * failure.
    110  */
    111 
    112 int
    113 number(const char *s)
    114 {
    115 	char *ep = NULL;
    116 	intmax_t n;
    117 
    118 	if (!is_digit(*s) || ((n = strtoimax(s, &ep, 10)),
    119 	    (ep == NULL || ep == s || *ep != '\0')))
    120 		error("Invalid number: '%s'", s);
    121 	if (n < INT_MIN || n > INT_MAX)
    122 		error("Number out of range: %s", s);
    123 	return (int)n;
    124 }
    125 
    126 
    127 
    128 /*
    129  * Check for a valid number.  This should be elsewhere.
    130  */
    131 
    132 int
    133 is_number(const char *p)
    134 {
    135 	do {
    136 		if (! is_digit(*p))
    137 			return 0;
    138 	} while (*++p != '\0');
    139 	return 1;
    140 }
    141