xref: /openbmc/u-boot/include/slre.h (revision df11b0c4)
1 /*
2  * Copyright (c) 2004-2005 Sergey Lyubka <valenok@gmail.com>
3  * All rights reserved
4  *
5  * "THE BEER-WARE LICENSE" (Revision 42):
6  * Sergey Lyubka wrote this file.  As long as you retain this notice you
7  * can do whatever you want with this stuff. If we meet some day, and you think
8  * this stuff is worth it, you can buy me a beer in return.
9  */
10 
11 /*
12  * Downloaded Sat Nov  5 17:42:08 CET 2011 at
13  * http://slre.sourceforge.net/1.0/slre.h
14  */
15 
16 /*
17  * This is a regular expression library that implements a subset of Perl RE.
18  * Please refer to http://slre.sourceforge.net for detailed description.
19  *
20  * Usage example (parsing HTTP request):
21  *
22  * struct slre	slre;
23  * struct cap	captures[4 + 1];  // Number of braket pairs + 1
24  * ...
25  *
26  * slre_compile(&slre,"^(GET|POST) (\S+) HTTP/(\S+?)\r\n");
27  *
28  * if (slre_match(&slre, buf, len, captures)) {
29  *	printf("Request line length: %d\n", captures[0].len);
30  *	printf("Method: %.*s\n", captures[1].len, captures[1].ptr);
31  *	printf("URI: %.*s\n", captures[2].len, captures[2].ptr);
32  * }
33  *
34  * Supported syntax:
35  *	^		Match beginning of a buffer
36  *	$		Match end of a buffer
37  *	()		Grouping and substring capturing
38  *	[...]		Match any character from set
39  *	[^...]		Match any character but ones from set
40  *	\s		Match whitespace
41  *	\S		Match non-whitespace
42  *	\d		Match decimal digit
43  *	\r		Match carriage return
44  *	\n		Match newline
45  *	+		Match one or more times (greedy)
46  *	+?		Match one or more times (non-greedy)
47  *	*		Match zero or more times (greedy)
48  *	*?		Match zero or more times (non-greedy)
49  *	?		Match zero or once
50  *	\xDD		Match byte with hex value 0xDD
51  *	\meta		Match one of the meta character: ^$().[*+?\
52  */
53 
54 #ifndef SLRE_HEADER_DEFINED
55 #define	SLRE_HEADER_DEFINED
56 
57 /*
58  * Compiled regular expression
59  */
60 struct slre {
61 	unsigned char	code[256];
62 	unsigned char	data[256];
63 	int		code_size;
64 	int		data_size;
65 	int		num_caps;	/* Number of bracket pairs	*/
66 	int		anchored;	/* Must match from string start	*/
67 	const char	*err_str;	/* Error string			*/
68 };
69 
70 /*
71  * Captured substring
72  */
73 struct cap {
74 	const char	*ptr;		/* Pointer to the substring	*/
75 	int		len;		/* Substring length		*/
76 };
77 
78 /*
79  * Compile regular expression. If success, 1 is returned.
80  * If error, 0 is returned and slre.err_str points to the error message.
81  */
82 int slre_compile(struct slre *, const char *re);
83 
84 /*
85  * Return 1 if match, 0 if no match.
86  * If `captured_substrings' array is not NULL, then it is filled with the
87  * values of captured substrings. captured_substrings[0] element is always
88  * a full matched substring. The round bracket captures start from
89  * captured_substrings[1].
90  * It is assumed that the size of captured_substrings array is enough to
91  * hold all captures. The caller function must make sure it is! So, the
92  * array_size = number_of_round_bracket_pairs + 1
93  */
94 int slre_match(const struct slre *, const char *buf, int buf_len,
95 	struct cap *captured_substrings);
96 
97 #ifdef SLRE_TEST
98 void slre_dump(const struct slre *r, FILE *fp);
99 #endif /* SLRE_TEST */
100 #endif /* SLRE_HEADER_DEFINED */
101