1 /*
2
3 Modified for PHP by Andrei Zmievski <andrei@ispi.net>
4
5 strnatcmp.c -- Perform 'natural order' comparisons of strings in C.
6 Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>
7
8 This software is provided 'as-is', without any express or implied
9 warranty. In no event will the authors be held liable for any damages
10 arising from the use of this software.
11
12 Permission is granted to anyone to use this software for any purpose,
13 including commercial applications, and to alter it and redistribute it
14 freely, subject to the following restrictions:
15
16 1. The origin of this software must not be misrepresented; you must not
17 claim that you wrote the original software. If you use this software
18 in a product, an acknowledgment in the product documentation would be
19 appreciated but is not required.
20 2. Altered source versions must be plainly marked as such, and must not be
21 misrepresented as being the original software.
22 3. This notice may not be removed or altered from any source distribution.
23 */
24
25 #include <ctype.h>
26 #include <string.h>
27 #include <stdio.h>
28
29 #include "php.h"
30 #include "php_string.h"
31
32 /* {{{ compare_right */
33 static int
compare_right(char const ** a,char const * aend,char const ** b,char const * bend)34 compare_right(char const **a, char const *aend, char const **b, char const *bend)
35 {
36 int bias = 0;
37
38 /* The longest run of digits wins. That aside, the greatest
39 value wins, but we can't know that it will until we've scanned
40 both numbers to know that they have the same magnitude, so we
41 remember it in BIAS. */
42 for(;; (*a)++, (*b)++) {
43 if ((*a == aend || !isdigit((int)(unsigned char)**a)) &&
44 (*b == bend || !isdigit((int)(unsigned char)**b)))
45 return bias;
46 else if (*a == aend || !isdigit((int)(unsigned char)**a))
47 return -1;
48 else if (*b == bend || !isdigit((int)(unsigned char)**b))
49 return +1;
50 else if (**a < **b) {
51 if (!bias)
52 bias = -1;
53 } else if (**a > **b) {
54 if (!bias)
55 bias = +1;
56 }
57 }
58
59 return 0;
60 }
61 /* }}} */
62
63 /* {{{ compare_left */
64 static int
compare_left(char const ** a,char const * aend,char const ** b,char const * bend)65 compare_left(char const **a, char const *aend, char const **b, char const *bend)
66 {
67 /* Compare two left-aligned numbers: the first to have a
68 different value wins. */
69 for(;; (*a)++, (*b)++) {
70 if ((*a == aend || !isdigit((int)(unsigned char)**a)) &&
71 (*b == bend || !isdigit((int)(unsigned char)**b)))
72 return 0;
73 else if (*a == aend || !isdigit((int)(unsigned char)**a))
74 return -1;
75 else if (*b == bend || !isdigit((int)(unsigned char)**b))
76 return +1;
77 else if (**a < **b)
78 return -1;
79 else if (**a > **b)
80 return +1;
81 }
82
83 return 0;
84 }
85 /* }}} */
86
87 /* {{{ strnatcmp_ex */
strnatcmp_ex(char const * a,size_t a_len,char const * b,size_t b_len,int fold_case)88 PHPAPI int strnatcmp_ex(char const *a, size_t a_len, char const *b, size_t b_len, int fold_case)
89 {
90 unsigned char ca, cb;
91 char const *ap, *bp;
92 char const *aend = a + a_len,
93 *bend = b + b_len;
94 int fractional, result;
95 short leading = 1;
96
97 if (a_len == 0 || b_len == 0) {
98 return (a_len == b_len ? 0 : (a_len > b_len ? 1 : -1));
99 }
100
101 ap = a;
102 bp = b;
103 while (1) {
104 ca = *ap; cb = *bp;
105
106 /* skip over leading zeros */
107 while (leading && ca == '0' && (ap+1 < aend) && isdigit((int)(unsigned char)*(ap+1))) {
108 ca = *++ap;
109 }
110
111 while (leading && cb == '0' && (bp+1 < bend) && isdigit((int)(unsigned char)*(bp+1))) {
112 cb = *++bp;
113 }
114
115 leading = 0;
116
117 /* Skip consecutive whitespace */
118 while (isspace((int)(unsigned char)ca)) {
119 ca = *++ap;
120 }
121
122 while (isspace((int)(unsigned char)cb)) {
123 cb = *++bp;
124 }
125
126 /* process run of digits */
127 if (isdigit((int)(unsigned char)ca) && isdigit((int)(unsigned char)cb)) {
128 fractional = (ca == '0' || cb == '0');
129
130 if (fractional)
131 result = compare_left(&ap, aend, &bp, bend);
132 else
133 result = compare_right(&ap, aend, &bp, bend);
134
135 if (result != 0)
136 return result;
137 else if (ap == aend && bp == bend)
138 /* End of the strings. Let caller sort them out. */
139 return 0;
140 else if (ap == aend)
141 return -1;
142 else if (bp == bend)
143 return 1;
144 else {
145 /* Keep on comparing from the current point. */
146 ca = *ap; cb = *bp;
147 }
148 }
149
150 if (fold_case) {
151 ca = toupper((int)(unsigned char)ca);
152 cb = toupper((int)(unsigned char)cb);
153 }
154
155 if (ca < cb)
156 return -1;
157 else if (ca > cb)
158 return +1;
159
160 ++ap; ++bp;
161 if (ap >= aend && bp >= bend)
162 /* The strings compare the same. Perhaps the caller
163 will want to call strcmp to break the tie. */
164 return 0;
165 else if (ap >= aend)
166 return -1;
167 else if (bp >= bend)
168 return 1;
169 }
170 }
171 /* }}} */
172
