CodingGuidelines: mention C whitespace rules
[git] / wildmatch.c
1 /*
2 **  Do shell-style pattern matching for ?, \, [], and * characters.
3 **  It is 8bit clean.
4 **
5 **  Written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
6 **  Rich $alz is now <rsalz@bbn.com>.
7 **
8 **  Modified by Wayne Davison to special-case '/' matching, to make '**'
9 **  work differently than '*', and to fix the character-class code.
10 */
11
12 #include "cache.h"
13 #include "wildmatch.h"
14
15 typedef unsigned char uchar;
16
17 /* What character marks an inverted character class? */
18 #define NEGATE_CLASS    '!'
19 #define NEGATE_CLASS2   '^'
20
21 #define CC_EQ(class, len, litmatch) ((len) == sizeof (litmatch)-1 \
22                                     && *(class) == *(litmatch) \
23                                     && strncmp((char*)class, litmatch, len) == 0)
24
25 #if defined STDC_HEADERS || !defined isascii
26 # define ISASCII(c) 1
27 #else
28 # define ISASCII(c) isascii(c)
29 #endif
30
31 #ifdef isblank
32 # define ISBLANK(c) (ISASCII(c) && isblank(c))
33 #else
34 # define ISBLANK(c) ((c) == ' ' || (c) == '\t')
35 #endif
36
37 #ifdef isgraph
38 # define ISGRAPH(c) (ISASCII(c) && isgraph(c))
39 #else
40 # define ISGRAPH(c) (ISASCII(c) && isprint(c) && !isspace(c))
41 #endif
42
43 #define ISPRINT(c) (ISASCII(c) && isprint(c))
44 #define ISDIGIT(c) (ISASCII(c) && isdigit(c))
45 #define ISALNUM(c) (ISASCII(c) && isalnum(c))
46 #define ISALPHA(c) (ISASCII(c) && isalpha(c))
47 #define ISCNTRL(c) (ISASCII(c) && iscntrl(c))
48 #define ISLOWER(c) (ISASCII(c) && islower(c))
49 #define ISPUNCT(c) (ISASCII(c) && ispunct(c))
50 #define ISSPACE(c) (ISASCII(c) && isspace(c))
51 #define ISUPPER(c) (ISASCII(c) && isupper(c))
52 #define ISXDIGIT(c) (ISASCII(c) && isxdigit(c))
53
54 /* Match pattern "p" against "text" */
55 static int dowild(const uchar *p, const uchar *text, unsigned int flags)
56 {
57         uchar p_ch;
58         const uchar *pattern = p;
59
60         for ( ; (p_ch = *p) != '\0'; text++, p++) {
61                 int matched, match_slash, negated;
62                 uchar t_ch, prev_ch;
63                 if ((t_ch = *text) == '\0' && p_ch != '*')
64                         return WM_ABORT_ALL;
65                 if ((flags & WM_CASEFOLD) && ISUPPER(t_ch))
66                         t_ch = tolower(t_ch);
67                 if ((flags & WM_CASEFOLD) && ISUPPER(p_ch))
68                         p_ch = tolower(p_ch);
69                 switch (p_ch) {
70                 case '\\':
71                         /* Literal match with following character.  Note that the test
72                          * in "default" handles the p[1] == '\0' failure case. */
73                         p_ch = *++p;
74                         /* FALLTHROUGH */
75                 default:
76                         if (t_ch != p_ch)
77                                 return WM_NOMATCH;
78                         continue;
79                 case '?':
80                         /* Match anything but '/'. */
81                         if ((flags & WM_PATHNAME) && t_ch == '/')
82                                 return WM_NOMATCH;
83                         continue;
84                 case '*':
85                         if (*++p == '*') {
86                                 const uchar *prev_p = p - 2;
87                                 while (*++p == '*') {}
88                                 if (!(flags & WM_PATHNAME))
89                                         /* without WM_PATHNAME, '*' == '**' */
90                                         match_slash = 1;
91                                 else if ((prev_p < pattern || *prev_p == '/') &&
92                                     (*p == '\0' || *p == '/' ||
93                                      (p[0] == '\\' && p[1] == '/'))) {
94                                         /*
95                                          * Assuming we already match 'foo/' and are at
96                                          * <star star slash>, just assume it matches
97                                          * nothing and go ahead match the rest of the
98                                          * pattern with the remaining string. This
99                                          * helps make foo/<*><*>/bar (<> because
100                                          * otherwise it breaks C comment syntax) match
101                                          * both foo/bar and foo/a/bar.
102                                          */
103                                         if (p[0] == '/' &&
104                                             dowild(p + 1, text, flags) == WM_MATCH)
105                                                 return WM_MATCH;
106                                         match_slash = 1;
107                                 } else
108                                         return WM_ABORT_MALFORMED;
109                         } else
110                                 /* without WM_PATHNAME, '*' == '**' */
111                                 match_slash = flags & WM_PATHNAME ? 0 : 1;
112                         if (*p == '\0') {
113                                 /* Trailing "**" matches everything.  Trailing "*" matches
114                                  * only if there are no more slash characters. */
115                                 if (!match_slash) {
116                                         if (strchr((char*)text, '/') != NULL)
117                                                 return WM_NOMATCH;
118                                 }
119                                 return WM_MATCH;
120                         } else if (!match_slash && *p == '/') {
121                                 /*
122                                  * _one_ asterisk followed by a slash
123                                  * with WM_PATHNAME matches the next
124                                  * directory
125                                  */
126                                 const char *slash = strchr((char*)text, '/');
127                                 if (!slash)
128                                         return WM_NOMATCH;
129                                 text = (const uchar*)slash;
130                                 /* the slash is consumed by the top-level for loop */
131                                 break;
132                         }
133                         while (1) {
134                                 if (t_ch == '\0')
135                                         break;
136                                 /*
137                                  * Try to advance faster when an asterisk is
138                                  * followed by a literal. We know in this case
139                                  * that the the string before the literal
140                                  * must belong to "*".
141                                  * If match_slash is false, do not look past
142                                  * the first slash as it cannot belong to '*'.
143                                  */
144                                 if (!is_glob_special(*p)) {
145                                         p_ch = *p;
146                                         if ((flags & WM_CASEFOLD) && ISUPPER(p_ch))
147                                                 p_ch = tolower(p_ch);
148                                         while ((t_ch = *text) != '\0' &&
149                                                (match_slash || t_ch != '/')) {
150                                                 if ((flags & WM_CASEFOLD) && ISUPPER(t_ch))
151                                                         t_ch = tolower(t_ch);
152                                                 if (t_ch == p_ch)
153                                                         break;
154                                                 text++;
155                                         }
156                                         if (t_ch != p_ch)
157                                                 return WM_NOMATCH;
158                                 }
159                                 if ((matched = dowild(p, text, flags)) != WM_NOMATCH) {
160                                         if (!match_slash || matched != WM_ABORT_TO_STARSTAR)
161                                                 return matched;
162                                 } else if (!match_slash && t_ch == '/')
163                                         return WM_ABORT_TO_STARSTAR;
164                                 t_ch = *++text;
165                         }
166                         return WM_ABORT_ALL;
167                 case '[':
168                         p_ch = *++p;
169 #ifdef NEGATE_CLASS2
170                         if (p_ch == NEGATE_CLASS2)
171                                 p_ch = NEGATE_CLASS;
172 #endif
173                         /* Assign literal 1/0 because of "matched" comparison. */
174                         negated = p_ch == NEGATE_CLASS ? 1 : 0;
175                         if (negated) {
176                                 /* Inverted character class. */
177                                 p_ch = *++p;
178                         }
179                         prev_ch = 0;
180                         matched = 0;
181                         do {
182                                 if (!p_ch)
183                                         return WM_ABORT_ALL;
184                                 if (p_ch == '\\') {
185                                         p_ch = *++p;
186                                         if (!p_ch)
187                                                 return WM_ABORT_ALL;
188                                         if (t_ch == p_ch)
189                                                 matched = 1;
190                                 } else if (p_ch == '-' && prev_ch && p[1] && p[1] != ']') {
191                                         p_ch = *++p;
192                                         if (p_ch == '\\') {
193                                                 p_ch = *++p;
194                                                 if (!p_ch)
195                                                         return WM_ABORT_ALL;
196                                         }
197                                         if (t_ch <= p_ch && t_ch >= prev_ch)
198                                                 matched = 1;
199                                         else if ((flags & WM_CASEFOLD) && ISLOWER(t_ch)) {
200                                                 uchar t_ch_upper = toupper(t_ch);
201                                                 if (t_ch_upper <= p_ch && t_ch_upper >= prev_ch)
202                                                         matched = 1;
203                                         }
204                                         p_ch = 0; /* This makes "prev_ch" get set to 0. */
205                                 } else if (p_ch == '[' && p[1] == ':') {
206                                         const uchar *s;
207                                         int i;
208                                         for (s = p += 2; (p_ch = *p) && p_ch != ']'; p++) {} /*SHARED ITERATOR*/
209                                         if (!p_ch)
210                                                 return WM_ABORT_ALL;
211                                         i = p - s - 1;
212                                         if (i < 0 || p[-1] != ':') {
213                                                 /* Didn't find ":]", so treat like a normal set. */
214                                                 p = s - 2;
215                                                 p_ch = '[';
216                                                 if (t_ch == p_ch)
217                                                         matched = 1;
218                                                 continue;
219                                         }
220                                         if (CC_EQ(s,i, "alnum")) {
221                                                 if (ISALNUM(t_ch))
222                                                         matched = 1;
223                                         } else if (CC_EQ(s,i, "alpha")) {
224                                                 if (ISALPHA(t_ch))
225                                                         matched = 1;
226                                         } else if (CC_EQ(s,i, "blank")) {
227                                                 if (ISBLANK(t_ch))
228                                                         matched = 1;
229                                         } else if (CC_EQ(s,i, "cntrl")) {
230                                                 if (ISCNTRL(t_ch))
231                                                         matched = 1;
232                                         } else if (CC_EQ(s,i, "digit")) {
233                                                 if (ISDIGIT(t_ch))
234                                                         matched = 1;
235                                         } else if (CC_EQ(s,i, "graph")) {
236                                                 if (ISGRAPH(t_ch))
237                                                         matched = 1;
238                                         } else if (CC_EQ(s,i, "lower")) {
239                                                 if (ISLOWER(t_ch))
240                                                         matched = 1;
241                                         } else if (CC_EQ(s,i, "print")) {
242                                                 if (ISPRINT(t_ch))
243                                                         matched = 1;
244                                         } else if (CC_EQ(s,i, "punct")) {
245                                                 if (ISPUNCT(t_ch))
246                                                         matched = 1;
247                                         } else if (CC_EQ(s,i, "space")) {
248                                                 if (ISSPACE(t_ch))
249                                                         matched = 1;
250                                         } else if (CC_EQ(s,i, "upper")) {
251                                                 if (ISUPPER(t_ch))
252                                                         matched = 1;
253                                                 else if ((flags & WM_CASEFOLD) && ISLOWER(t_ch))
254                                                         matched = 1;
255                                         } else if (CC_EQ(s,i, "xdigit")) {
256                                                 if (ISXDIGIT(t_ch))
257                                                         matched = 1;
258                                         } else /* malformed [:class:] string */
259                                                 return WM_ABORT_ALL;
260                                         p_ch = 0; /* This makes "prev_ch" get set to 0. */
261                                 } else if (t_ch == p_ch)
262                                         matched = 1;
263                         } while (prev_ch = p_ch, (p_ch = *++p) != ']');
264                         if (matched == negated ||
265                             ((flags & WM_PATHNAME) && t_ch == '/'))
266                                 return WM_NOMATCH;
267                         continue;
268                 }
269         }
270
271         return *text ? WM_NOMATCH : WM_MATCH;
272 }
273
274 /* Match the "pattern" against the "text" string. */
275 int wildmatch(const char *pattern, const char *text,
276               unsigned int flags, struct wildopts *wo)
277 {
278         return dowild((const uchar*)pattern, (const uchar*)text, flags);
279 }