summaryrefslogtreecommitdiff
path: root/ext/standard/strnatcmp.c
blob: e1f491a3df48b8f743d65b70362509ad99ad0dde (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/* -*- mode: c; c-file-style: "k&r" -*-

  Modified for PHP by Andrei Zmievski <andrei@ispi.net>

  strnatcmp.c -- Perform 'natural order' comparisons of strings in C.
  Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

#include <ctype.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>

#include "php.h"
#include "php_string.h"

#if defined(__GNUC__)
#  define UNUSED __attribute__((__unused__))
#else
#  define UNUSED
#endif

#if 0
static char const *version UNUSED =
    "$Id$";
#endif
/* {{{ compare_right
 */
static int
compare_right(char const **a, char const *aend, char const **b, char const *bend)
{
	int bias = 0;

	/* The longest run of digits wins.  That aside, the greatest
	   value wins, but we can't know that it will until we've scanned
	   both numbers to know that they have the same magnitude, so we
	   remember it in BIAS. */
	for(;; (*a)++, (*b)++) {
		if ((*a == aend || !isdigit((int)(unsigned char)**a)) &&
			(*b == bend || !isdigit((int)(unsigned char)**b)))
			return bias;
		else if (*a == aend || !isdigit((int)(unsigned char)**a))
			return -1;
		else if (*b == bend || !isdigit((int)(unsigned char)**b))
			return +1;
		else if (**a < **b) {
			if (!bias)
				bias = -1;
		} else if (**a > **b) {
			if (!bias)
				bias = +1;
		}
     }

     return 0;
}
/* }}} */

/* {{{ compare_left
 */
static int
compare_left(char const **a, char const *aend, char const **b, char const *bend)
{
     /* Compare two left-aligned numbers: the first to have a
        different value wins. */
	for(;; (*a)++, (*b)++) {
		if ((*a == aend || !isdigit((int)(unsigned char)**a)) &&
			(*b == bend || !isdigit((int)(unsigned char)**b)))
			return 0;
		else if (*a == aend || !isdigit((int)(unsigned char)**a))
			return -1;
		else if (*b == bend || !isdigit((int)(unsigned char)**b))
			return +1;
		 else if (**a < **b)
			 return -1;
		 else if (**a > **b)
			 return +1;
     }
	  
     return 0;
}
/* }}} */

/* {{{ strnatcmp_ex
 */
PHPAPI int strnatcmp_ex(char const *a, size_t a_len, char const *b, size_t b_len, int fold_case)
{
	char ca, cb;
	char const *ap, *bp;
	char const *aend = a + a_len,
			   *bend = b + b_len;
	int fractional, result;

	if (a_len == 0 || b_len == 0)
		return a_len - b_len;

	ap = a;
	bp = b;
	while (1) {
		ca = *ap; cb = *bp;

		/* skip over leading spaces or zeros */
		while (isspace((int)(unsigned char)ca))
			ca = *++ap;

		while (isspace((int)(unsigned char)cb))
			cb = *++bp;

		/* process run of digits */
		if (isdigit((int)(unsigned char)ca)  &&  isdigit((int)(unsigned char)cb)) {
			fractional = (ca == '0' || cb == '0');

			if (fractional)
				result = compare_left(&ap, aend, &bp, bend);
			else
				result = compare_right(&ap, aend, &bp, bend);

			if (result != 0)
				return result;
			else if (ap == aend && bp == bend)
				/* End of the strings. Let caller sort them out. */
				return 0;
			else {
				/* Keep on comparing from the current point. */
				ca = *ap; cb = *bp;
			}
		}

		if (fold_case) {
			ca = toupper((int)(unsigned char)ca);
			cb = toupper((int)(unsigned char)cb);
		}

		if (ca < cb)
			return -1;
		else if (ca > cb)
			return +1;

		++ap; ++bp;
		if (ap >= aend && bp >= bend)
			/* The strings compare the same.  Perhaps the caller
			   will want to call strcmp to break the tie. */
			return 0;
		else if (ap >= aend)
			return -1;
		else if (bp >= bend)
			return 1;
	}
}
/* }}} */

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: sw=4 ts=4 fdm=marker
 * vim<600: sw=4 ts=4
 */