xref: /freebsd/lib/libc/locale/fix_grouping.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2001 Alexey Zelkin <phantom@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <ctype.h>
31 #include <limits.h>
32 #include <stddef.h>
33 
34 static const char nogrouping[] = { '\0' };
35 
36 /*
37  * Internal helper used to convert grouping sequences from string
38  * representation into POSIX specified form, i.e.
39  *
40  * "3;3;-1" -> "\003\003\177\000"
41  */
42 
43 const char *
44 __fix_locale_grouping_str(const char *str)
45 {
46 	char *src, *dst;
47 	char n;
48 
49 	if (str == NULL || *str == '\0') {
50 		return nogrouping;
51 	}
52 
53 	for (src = (char*)str, dst = (char*)str; *src != '\0'; src++) {
54 
55 		/* input string examples: "3;3", "3;2;-1" */
56 		if (*src == ';')
57 			continue;
58 
59 		if (*src == '-' && *(src+1) == '1') {
60 			*dst++ = CHAR_MAX;
61 			src++;
62 			continue;
63 		}
64 
65 		if (!isdigit((unsigned char)*src)) {
66 			/* broken grouping string */
67 			return nogrouping;
68 		}
69 
70 		/* assume all numbers <= 99 */
71 		n = *src - '0';
72 		if (isdigit((unsigned char)*(src+1))) {
73 			src++;
74 			n *= 10;
75 			n += *src - '0';
76 		}
77 
78 		*dst = n;
79 		/* NOTE: assume all input started with "0" as 'no grouping' */
80 		if (*dst == '\0')
81 			return (dst == (char*)str) ? nogrouping : str;
82 		dst++;
83 	}
84 	*dst = '\0';
85 	return str;
86 }
87