Annotation of embedaddon/pcre/doc/pcre16.3, revision 1.1.1.2
1.1.1.2 ! misho 1: .TH PCRE 3 "14 April 2012" "PCRE 8.31"
1.1 misho 2: .SH NAME
3: PCRE - Perl-compatible regular expressions
4: .sp
5: .B #include <pcre.h>
6: .
7: .
8: .SH "PCRE 16-BIT API BASIC FUNCTIONS"
9: .rs
10: .sp
11: .SM
12: .B pcre16 *pcre16_compile(PCRE_SPTR16 \fIpattern\fP, int \fIoptions\fP,
13: .ti +5n
14: .B const char **\fIerrptr\fP, int *\fIerroffset\fP,
15: .ti +5n
16: .B const unsigned char *\fItableptr\fP);
17: .PP
18: .B pcre16 *pcre16_compile2(PCRE_SPTR16 \fIpattern\fP, int \fIoptions\fP,
19: .ti +5n
20: .B int *\fIerrorcodeptr\fP,
21: .ti +5n
22: .B const char **\fIerrptr\fP, int *\fIerroffset\fP,
23: .ti +5n
24: .B const unsigned char *\fItableptr\fP);
25: .PP
26: .B pcre16_extra *pcre16_study(const pcre16 *\fIcode\fP, int \fIoptions\fP,
27: .ti +5n
28: .B const char **\fIerrptr\fP);
29: .PP
30: .B void pcre16_free_study(pcre16_extra *\fIextra\fP);
31: .PP
32: .B int pcre16_exec(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
33: .ti +5n
34: .B "PCRE_SPTR16 \fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
35: .ti +5n
36: .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);
37: .PP
38: .B int pcre16_dfa_exec(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
39: .ti +5n
40: .B "PCRE_SPTR16 \fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
41: .ti +5n
42: .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP,
43: .ti +5n
44: .B int *\fIworkspace\fP, int \fIwscount\fP);
45: .
46: .
47: .SH "PCRE 16-BIT API STRING EXTRACTION FUNCTIONS"
48: .rs
49: .sp
50: .B int pcre16_copy_named_substring(const pcre16 *\fIcode\fP,
51: .ti +5n
52: .B PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
53: .ti +5n
54: .B int \fIstringcount\fP, PCRE_SPTR16 \fIstringname\fP,
55: .ti +5n
56: .B PCRE_UCHAR16 *\fIbuffer\fP, int \fIbuffersize\fP);
57: .PP
58: .B int pcre16_copy_substring(PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
59: .ti +5n
60: .B int \fIstringcount\fP, int \fIstringnumber\fP, PCRE_UCHAR16 *\fIbuffer\fP,
61: .ti +5n
62: .B int \fIbuffersize\fP);
63: .PP
64: .B int pcre16_get_named_substring(const pcre16 *\fIcode\fP,
65: .ti +5n
66: .B PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
67: .ti +5n
68: .B int \fIstringcount\fP, PCRE_SPTR16 \fIstringname\fP,
69: .ti +5n
70: .B PCRE_SPTR16 *\fIstringptr\fP);
71: .PP
72: .B int pcre16_get_stringnumber(const pcre16 *\fIcode\fP,
73: .ti +5n
74: .B PCRE_SPTR16 \fIname\fP);
75: .PP
76: .B int pcre16_get_stringtable_entries(const pcre16 *\fIcode\fP,
77: .ti +5n
78: .B PCRE_SPTR16 \fIname\fP, PCRE_UCHAR16 **\fIfirst\fP, PCRE_UCHAR16 **\fIlast\fP);
79: .PP
80: .B int pcre16_get_substring(PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
81: .ti +5n
82: .B int \fIstringcount\fP, int \fIstringnumber\fP,
83: .ti +5n
84: .B PCRE_SPTR16 *\fIstringptr\fP);
85: .PP
86: .B int pcre16_get_substring_list(PCRE_SPTR16 \fIsubject\fP,
87: .ti +5n
88: .B int *\fIovector\fP, int \fIstringcount\fP, "PCRE_SPTR16 **\fIlistptr\fP);"
89: .PP
90: .B void pcre16_free_substring(PCRE_SPTR16 \fIstringptr\fP);
91: .PP
92: .B void pcre16_free_substring_list(PCRE_SPTR16 *\fIstringptr\fP);
93: .
94: .
95: .SH "PCRE 16-BIT API AUXILIARY FUNCTIONS"
96: .rs
97: .sp
98: .B pcre16_jit_stack *pcre16_jit_stack_alloc(int \fIstartsize\fP, int \fImaxsize\fP);
99: .PP
100: .B void pcre16_jit_stack_free(pcre16_jit_stack *\fIstack\fP);
101: .PP
102: .B void pcre16_assign_jit_stack(pcre16_extra *\fIextra\fP,
103: .ti +5n
104: .B pcre16_jit_callback \fIcallback\fP, void *\fIdata\fP);
105: .PP
106: .B const unsigned char *pcre16_maketables(void);
107: .PP
108: .B int pcre16_fullinfo(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
109: .ti +5n
110: .B int \fIwhat\fP, void *\fIwhere\fP);
111: .PP
112: .B int pcre16_refcount(pcre16 *\fIcode\fP, int \fIadjust\fP);
113: .PP
114: .B int pcre16_config(int \fIwhat\fP, void *\fIwhere\fP);
115: .PP
116: .B const char *pcre16_version(void);
117: .PP
118: .B int pcre16_pattern_to_host_byte_order(pcre16 *\fIcode\fP,
119: .ti +5n
120: .B pcre16_extra *\fIextra\fP, const unsigned char *\fItables\fP);
121: .
122: .
123: .SH "PCRE 16-BIT API INDIRECTED FUNCTIONS"
124: .rs
125: .sp
126: .B void *(*pcre16_malloc)(size_t);
127: .PP
128: .B void (*pcre16_free)(void *);
129: .PP
130: .B void *(*pcre16_stack_malloc)(size_t);
131: .PP
132: .B void (*pcre16_stack_free)(void *);
133: .PP
134: .B int (*pcre16_callout)(pcre16_callout_block *);
135: .
136: .
137: .SH "PCRE 16-BIT API 16-BIT-ONLY FUNCTION"
138: .rs
139: .sp
140: .B int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *\fIoutput\fP,
141: .ti +5n
142: .B PCRE_SPTR16 \fIinput\fP, int \fIlength\fP, int *\fIbyte_order\fP,
143: .ti +5n
144: .B int \fIkeep_boms\fP);
145: .
146: .
147: .SH "THE PCRE 16-BIT LIBRARY"
148: .rs
149: .sp
150: Starting with release 8.30, it is possible to compile a PCRE library that
151: supports 16-bit character strings, including UTF-16 strings, as well as or
152: instead of the original 8-bit library. The majority of the work to make this
153: possible was done by Zoltan Herczeg. The two libraries contain identical sets
154: of functions, used in exactly the same way. Only the names of the functions and
155: the data types of their arguments and results are different. To avoid
156: over-complication and reduce the documentation maintenance load, most of the
157: PCRE documentation describes the 8-bit library, with only occasional references
158: to the 16-bit library. This page describes what is different when you use the
159: 16-bit library.
160: .P
161: WARNING: A single application can be linked with both libraries, but you must
162: take care when processing any particular pattern to use functions from just one
163: library. For example, if you want to study a pattern that was compiled with
164: \fBpcre16_compile()\fP, you must do so with \fBpcre16_study()\fP, not
165: \fBpcre_study()\fP, and you must free the study data with
166: \fBpcre16_free_study()\fP.
167: .
168: .
169: .SH "THE HEADER FILE"
170: .rs
171: .sp
172: There is only one header file, \fBpcre.h\fP. It contains prototypes for all the
173: functions in both libraries, as well as definitions of flags, structures, error
174: codes, etc.
175: .
176: .
177: .SH "THE LIBRARY NAME"
178: .rs
179: .sp
180: In Unix-like systems, the 16-bit library is called \fBlibpcre16\fP, and can
181: normally be accesss by adding \fB-lpcre16\fP to the command for linking an
182: application that uses PCRE.
183: .
184: .
185: .SH "STRING TYPES"
186: .rs
187: .sp
188: In the 8-bit library, strings are passed to PCRE library functions as vectors
189: of bytes with the C type "char *". In the 16-bit library, strings are passed as
190: vectors of unsigned 16-bit quantities. The macro PCRE_UCHAR16 specifies an
191: appropriate data type, and PCRE_SPTR16 is defined as "const PCRE_UCHAR16 *". In
192: very many environments, "short int" is a 16-bit data type. When PCRE is built,
193: it defines PCRE_UCHAR16 as "short int", but checks that it really is a 16-bit
194: data type. If it is not, the build fails with an error message telling the
195: maintainer to modify the definition appropriately.
196: .
197: .
198: .SH "STRUCTURE TYPES"
199: .rs
200: .sp
201: The types of the opaque structures that are used for compiled 16-bit patterns
202: and JIT stacks are \fBpcre16\fP and \fBpcre16_jit_stack\fP respectively. The
203: type of the user-accessible structure that is returned by \fBpcre16_study()\fP
204: is \fBpcre16_extra\fP, and the type of the structure that is used for passing
205: data to a callout function is \fBpcre16_callout_block\fP. These structures
206: contain the same fields, with the same names, as their 8-bit counterparts. The
207: only difference is that pointers to character strings are 16-bit instead of
208: 8-bit types.
209: .
210: .
211: .SH "16-BIT FUNCTIONS"
212: .rs
213: .sp
214: For every function in the 8-bit library there is a corresponding function in
215: the 16-bit library with a name that starts with \fBpcre16_\fP instead of
216: \fBpcre_\fP. The prototypes are listed above. In addition, there is one extra
217: function, \fBpcre16_utf16_to_host_byte_order()\fP. This is a utility function
218: that converts a UTF-16 character string to host byte order if necessary. The
219: other 16-bit functions expect the strings they are passed to be in host byte
220: order.
221: .P
222: The \fIinput\fP and \fIoutput\fP arguments of
223: \fBpcre16_utf16_to_host_byte_order()\fP may point to the same address, that is,
224: conversion in place is supported. The output buffer must be at least as long as
225: the input.
226: .P
227: The \fIlength\fP argument specifies the number of 16-bit data units in the
228: input string; a negative value specifies a zero-terminated string.
229: .P
230: If \fIbyte_order\fP is NULL, it is assumed that the string starts off in host
231: byte order. This may be changed by byte-order marks (BOMs) anywhere in the
232: string (commonly as the first character).
233: .P
234: If \fIbyte_order\fP is not NULL, a non-zero value of the integer to which it
235: points means that the input starts off in host byte order, otherwise the
236: opposite order is assumed. Again, BOMs in the string can change this. The final
237: byte order is passed back at the end of processing.
238: .P
239: If \fIkeep_boms\fP is not zero, byte-order mark characters (0xfeff) are copied
240: into the output string. Otherwise they are discarded.
241: .P
242: The result of the function is the number of 16-bit units placed into the output
243: buffer, including the zero terminator if the string was zero-terminated.
244: .
245: .
246: .SH "SUBJECT STRING OFFSETS"
247: .rs
248: .sp
249: The offsets within subject strings that are returned by the matching functions
250: are in 16-bit units rather than bytes.
251: .
252: .
253: .SH "NAMED SUBPATTERNS"
254: .rs
255: .sp
256: The name-to-number translation table that is maintained for named subpatterns
257: uses 16-bit characters. The \fBpcre16_get_stringtable_entries()\fP function
258: returns the length of each entry in the table as the number of 16-bit data
259: units.
260: .
261: .
262: .SH "OPTION NAMES"
263: .rs
264: .sp
265: There are two new general option names, PCRE_UTF16 and PCRE_NO_UTF16_CHECK,
266: which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In
1.1.1.2 ! misho 267: fact, these new options define the same bits in the options word. There is a
! 268: discussion about the
! 269: .\" HTML <a href="pcreunicode.html#utf16strings">
! 270: .\" </a>
! 271: validity of UTF-16 strings
! 272: .\"
! 273: in the
! 274: .\" HREF
! 275: \fBpcreunicode\fP
! 276: .\"
! 277: page.
1.1 misho 278: .P
279: For the \fBpcre16_config()\fP function there is an option PCRE_CONFIG_UTF16
280: that returns 1 if UTF-16 support is configured, otherwise 0. If this option is
281: given to \fBpcre_config()\fP, or if the PCRE_CONFIG_UTF8 option is given to
282: \fBpcre16_config()\fP, the result is the PCRE_ERROR_BADOPTION error.
283: .
284: .
285: .SH "CHARACTER CODES"
286: .rs
287: .sp
288: In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the
289: same way as in 8-bit, non UTF-8 mode, except, of course, that they can range
290: from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than
291: 0xff can therefore be influenced by the locale in the same way as before.
292: Characters greater than 0xff have only one case, and no "type" (such as letter
293: or digit).
294: .P
295: In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with
296: the exception of values in the range 0xd800 to 0xdfff because those are
297: "surrogate" values that are used in pairs to encode values greater than 0xffff.
298: .P
299: A UTF-16 string can indicate its endianness by special code knows as a
300: byte-order mark (BOM). The PCRE functions do not handle this, expecting strings
301: to be in host byte order. A utility function called
302: \fBpcre16_utf16_to_host_byte_order()\fP is provided to help with this (see
303: above).
304: .
305: .
306: .SH "ERROR NAMES"
307: .rs
308: .sp
309: The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to
310: their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled
311: pattern is passed to a function that processes patterns in the other
312: mode, for example, if a pattern compiled with \fBpcre_compile()\fP is passed to
313: \fBpcre16_exec()\fP.
314: .P
315: There are new error codes whose names begin with PCRE_UTF16_ERR for invalid
316: UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that
317: are described in the section entitled
318: .\" HTML <a href="pcreapi.html#badutf8reasons">
319: .\" </a>
320: "Reason codes for invalid UTF-8 strings"
321: .\"
322: in the main
323: .\" HREF
324: \fBpcreapi\fP
325: .\"
326: page. The UTF-16 errors are:
327: .sp
328: PCRE_UTF16_ERR1 Missing low surrogate at end of string
329: PCRE_UTF16_ERR2 Invalid low surrogate follows high surrogate
330: PCRE_UTF16_ERR3 Isolated low surrogate
331: PCRE_UTF16_ERR4 Invalid character 0xfffe
332: .
333: .
334: .SH "ERROR TEXTS"
335: .rs
336: .sp
337: If there is an error while compiling a pattern, the error text that is passed
338: back by \fBpcre16_compile()\fP or \fBpcre16_compile2()\fP is still an 8-bit
339: character string, zero-terminated.
340: .
341: .
342: .SH "CALLOUTS"
343: .rs
344: .sp
345: The \fIsubject\fP and \fImark\fP fields in the callout block that is passed to
346: a callout function point to 16-bit vectors.
347: .
348: .
349: .SH "TESTING"
350: .rs
351: .sp
352: The \fBpcretest\fP program continues to operate with 8-bit input and output
353: files, but it can be used for testing the 16-bit library. If it is run with the
354: command line option \fB-16\fP, patterns and subject strings are converted from
355: 8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions
356: are used instead of the 8-bit ones. Returned 16-bit strings are converted to
357: 8-bit for output. If the 8-bit library was not compiled, \fBpcretest\fP
358: defaults to 16-bit and the \fB-16\fP option is ignored.
359: .P
360: When PCRE is being built, the \fBRunTest\fP script that is called by "make
361: check" uses the \fBpcretest\fP \fB-C\fP option to discover which of the 8-bit
362: and 16-bit libraries has been built, and runs the tests appropriately.
363: .
364: .
365: .SH "NOT SUPPORTED IN 16-BIT MODE"
366: .rs
367: .sp
368: Not all the features of the 8-bit library are available with the 16-bit
369: library. The C++ and POSIX wrapper functions support only the 8-bit library,
370: and the \fBpcregrep\fP program is at present 8-bit only.
371: .
372: .
373: .SH AUTHOR
374: .rs
375: .sp
376: .nf
377: Philip Hazel
378: University Computing Service
379: Cambridge CB2 3QH, England.
380: .fi
381: .
382: .
383: .SH REVISION
384: .rs
385: .sp
386: .nf
1.1.1.2 ! misho 387: Last updated: 14 April 2012
1.1 misho 388: Copyright (c) 1997-2012 University of Cambridge.
389: .fi
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