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1 <html>
2 <head>
3 <title>pcre16 specification</title>
4 </head>
5 <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6 <h1>pcre16 man page</h1>
7 <p>
8 Return to the <a href="index.html">PCRE index page</a>.
9 </p>
10 <p>
11 This page is part of the PCRE HTML documentation. It was generated automatically
12 from the original man page. If there is any nonsense in it, please consult the
13 man page, in case the conversion went wrong.
14 <br>
15 <ul>
16 <li><a name="TOC1" href="#SEC1">PCRE 16-BIT API BASIC FUNCTIONS</a>
17 <li><a name="TOC2" href="#SEC2">PCRE 16-BIT API STRING EXTRACTION FUNCTIONS</a>
18 <li><a name="TOC3" href="#SEC3">PCRE 16-BIT API AUXILIARY FUNCTIONS</a>
19 <li><a name="TOC4" href="#SEC4">PCRE 16-BIT API INDIRECTED FUNCTIONS</a>
20 <li><a name="TOC5" href="#SEC5">PCRE 16-BIT API 16-BIT-ONLY FUNCTION</a>
21 <li><a name="TOC6" href="#SEC6">THE PCRE 16-BIT LIBRARY</a>
22 <li><a name="TOC7" href="#SEC7">THE HEADER FILE</a>
23 <li><a name="TOC8" href="#SEC8">THE LIBRARY NAME</a>
24 <li><a name="TOC9" href="#SEC9">STRING TYPES</a>
25 <li><a name="TOC10" href="#SEC10">STRUCTURE TYPES</a>
26 <li><a name="TOC11" href="#SEC11">16-BIT FUNCTIONS</a>
27 <li><a name="TOC12" href="#SEC12">SUBJECT STRING OFFSETS</a>
28 <li><a name="TOC13" href="#SEC13">NAMED SUBPATTERNS</a>
29 <li><a name="TOC14" href="#SEC14">OPTION NAMES</a>
30 <li><a name="TOC15" href="#SEC15">CHARACTER CODES</a>
31 <li><a name="TOC16" href="#SEC16">ERROR NAMES</a>
32 <li><a name="TOC17" href="#SEC17">ERROR TEXTS</a>
33 <li><a name="TOC18" href="#SEC18">CALLOUTS</a>
34 <li><a name="TOC19" href="#SEC19">TESTING</a>
35 <li><a name="TOC20" href="#SEC20">NOT SUPPORTED IN 16-BIT MODE</a>
36 <li><a name="TOC21" href="#SEC21">AUTHOR</a>
37 <li><a name="TOC22" href="#SEC22">REVISION</a>
38 </ul>
39 <P>
40 <b>#include &#60;pcre.h&#62;</b>
41 </P>
42 <br><a name="SEC1" href="#TOC1">PCRE 16-BIT API BASIC FUNCTIONS</a><br>
43 <P>
44 <b>pcre16 *pcre16_compile(PCRE_SPTR16 <i>pattern</i>, int <i>options</i>,</b>
45 <b>const char **<i>errptr</i>, int *<i>erroffset</i>,</b>
46 <b>const unsigned char *<i>tableptr</i>);</b>
47 </P>
48 <P>
49 <b>pcre16 *pcre16_compile2(PCRE_SPTR16 <i>pattern</i>, int <i>options</i>,</b>
50 <b>int *<i>errorcodeptr</i>,</b>
51 <b>const char **<i>errptr</i>, int *<i>erroffset</i>,</b>
52 <b>const unsigned char *<i>tableptr</i>);</b>
53 </P>
54 <P>
55 <b>pcre16_extra *pcre16_study(const pcre16 *<i>code</i>, int <i>options</i>,</b>
56 <b>const char **<i>errptr</i>);</b>
57 </P>
58 <P>
59 <b>void pcre16_free_study(pcre16_extra *<i>extra</i>);</b>
60 </P>
61 <P>
62 <b>int pcre16_exec(const pcre16 *<i>code</i>, const pcre16_extra *<i>extra</i>,</b>
63 <b>PCRE_SPTR16 <i>subject</i>, int <i>length</i>, int <i>startoffset</i>,</b>
64 <b>int <i>options</i>, int *<i>ovector</i>, int <i>ovecsize</i>);</b>
65 </P>
66 <P>
67 <b>int pcre16_dfa_exec(const pcre16 *<i>code</i>, const pcre16_extra *<i>extra</i>,</b>
68 <b>PCRE_SPTR16 <i>subject</i>, int <i>length</i>, int <i>startoffset</i>,</b>
69 <b>int <i>options</i>, int *<i>ovector</i>, int <i>ovecsize</i>,</b>
70 <b>int *<i>workspace</i>, int <i>wscount</i>);</b>
71 </P>
72 <br><a name="SEC2" href="#TOC1">PCRE 16-BIT API STRING EXTRACTION FUNCTIONS</a><br>
73 <P>
74 <b>int pcre16_copy_named_substring(const pcre16 *<i>code</i>,</b>
75 <b>PCRE_SPTR16 <i>subject</i>, int *<i>ovector</i>,</b>
76 <b>int <i>stringcount</i>, PCRE_SPTR16 <i>stringname</i>,</b>
77 <b>PCRE_UCHAR16 *<i>buffer</i>, int <i>buffersize</i>);</b>
78 </P>
79 <P>
80 <b>int pcre16_copy_substring(PCRE_SPTR16 <i>subject</i>, int *<i>ovector</i>,</b>
81 <b>int <i>stringcount</i>, int <i>stringnumber</i>, PCRE_UCHAR16 *<i>buffer</i>,</b>
82 <b>int <i>buffersize</i>);</b>
83 </P>
84 <P>
85 <b>int pcre16_get_named_substring(const pcre16 *<i>code</i>,</b>
86 <b>PCRE_SPTR16 <i>subject</i>, int *<i>ovector</i>,</b>
87 <b>int <i>stringcount</i>, PCRE_SPTR16 <i>stringname</i>,</b>
88 <b>PCRE_SPTR16 *<i>stringptr</i>);</b>
89 </P>
90 <P>
91 <b>int pcre16_get_stringnumber(const pcre16 *<i>code</i>,</b>
92 <b>PCRE_SPTR16 <i>name</i>);</b>
93 </P>
94 <P>
95 <b>int pcre16_get_stringtable_entries(const pcre16 *<i>code</i>,</b>
96 <b>PCRE_SPTR16 <i>name</i>, PCRE_UCHAR16 **<i>first</i>, PCRE_UCHAR16 **<i>last</i>);</b>
97 </P>
98 <P>
99 <b>int pcre16_get_substring(PCRE_SPTR16 <i>subject</i>, int *<i>ovector</i>,</b>
100 <b>int <i>stringcount</i>, int <i>stringnumber</i>,</b>
101 <b>PCRE_SPTR16 *<i>stringptr</i>);</b>
102 </P>
103 <P>
104 <b>int pcre16_get_substring_list(PCRE_SPTR16 <i>subject</i>,</b>
105 <b>int *<i>ovector</i>, int <i>stringcount</i>, PCRE_SPTR16 **<i>listptr</i>);</b>
106 </P>
107 <P>
108 <b>void pcre16_free_substring(PCRE_SPTR16 <i>stringptr</i>);</b>
109 </P>
110 <P>
111 <b>void pcre16_free_substring_list(PCRE_SPTR16 *<i>stringptr</i>);</b>
112 </P>
113 <br><a name="SEC3" href="#TOC1">PCRE 16-BIT API AUXILIARY FUNCTIONS</a><br>
114 <P>
115 <b>pcre16_jit_stack *pcre16_jit_stack_alloc(int <i>startsize</i>, int <i>maxsize</i>);</b>
116 </P>
117 <P>
118 <b>void pcre16_jit_stack_free(pcre16_jit_stack *<i>stack</i>);</b>
119 </P>
120 <P>
121 <b>void pcre16_assign_jit_stack(pcre16_extra *<i>extra</i>,</b>
122 <b>pcre16_jit_callback <i>callback</i>, void *<i>data</i>);</b>
123 </P>
124 <P>
125 <b>const unsigned char *pcre16_maketables(void);</b>
126 </P>
127 <P>
128 <b>int pcre16_fullinfo(const pcre16 *<i>code</i>, const pcre16_extra *<i>extra</i>,</b>
129 <b>int <i>what</i>, void *<i>where</i>);</b>
130 </P>
131 <P>
132 <b>int pcre16_refcount(pcre16 *<i>code</i>, int <i>adjust</i>);</b>
133 </P>
134 <P>
135 <b>int pcre16_config(int <i>what</i>, void *<i>where</i>);</b>
136 </P>
137 <P>
138 <b>const char *pcre16_version(void);</b>
139 </P>
140 <P>
141 <b>int pcre16_pattern_to_host_byte_order(pcre16 *<i>code</i>,</b>
142 <b>pcre16_extra *<i>extra</i>, const unsigned char *<i>tables</i>);</b>
143 </P>
144 <br><a name="SEC4" href="#TOC1">PCRE 16-BIT API INDIRECTED FUNCTIONS</a><br>
145 <P>
146 <b>void *(*pcre16_malloc)(size_t);</b>
147 </P>
148 <P>
149 <b>void (*pcre16_free)(void *);</b>
150 </P>
151 <P>
152 <b>void *(*pcre16_stack_malloc)(size_t);</b>
153 </P>
154 <P>
155 <b>void (*pcre16_stack_free)(void *);</b>
156 </P>
157 <P>
158 <b>int (*pcre16_callout)(pcre16_callout_block *);</b>
159 </P>
160 <br><a name="SEC5" href="#TOC1">PCRE 16-BIT API 16-BIT-ONLY FUNCTION</a><br>
161 <P>
162 <b>int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *<i>output</i>,</b>
163 <b>PCRE_SPTR16 <i>input</i>, int <i>length</i>, int *<i>byte_order</i>,</b>
164 <b>int <i>keep_boms</i>);</b>
165 </P>
166 <br><a name="SEC6" href="#TOC1">THE PCRE 16-BIT LIBRARY</a><br>
167 <P>
168 Starting with release 8.30, it is possible to compile a PCRE library that
169 supports 16-bit character strings, including UTF-16 strings, as well as or
170 instead of the original 8-bit library. The majority of the work to make this
171 possible was done by Zoltan Herczeg. The two libraries contain identical sets
172 of functions, used in exactly the same way. Only the names of the functions and
173 the data types of their arguments and results are different. To avoid
174 over-complication and reduce the documentation maintenance load, most of the
175 PCRE documentation describes the 8-bit library, with only occasional references
176 to the 16-bit library. This page describes what is different when you use the
177 16-bit library.
178 </P>
179 <P>
180 WARNING: A single application can be linked with both libraries, but you must
181 take care when processing any particular pattern to use functions from just one
182 library. For example, if you want to study a pattern that was compiled with
183 <b>pcre16_compile()</b>, you must do so with <b>pcre16_study()</b>, not
184 <b>pcre_study()</b>, and you must free the study data with
185 <b>pcre16_free_study()</b>.
186 </P>
187 <br><a name="SEC7" href="#TOC1">THE HEADER FILE</a><br>
188 <P>
189 There is only one header file, <b>pcre.h</b>. It contains prototypes for all the
190 functions in both libraries, as well as definitions of flags, structures, error
191 codes, etc.
192 </P>
193 <br><a name="SEC8" href="#TOC1">THE LIBRARY NAME</a><br>
194 <P>
195 In Unix-like systems, the 16-bit library is called <b>libpcre16</b>, and can
196 normally be accesss by adding <b>-lpcre16</b> to the command for linking an
197 application that uses PCRE.
198 </P>
199 <br><a name="SEC9" href="#TOC1">STRING TYPES</a><br>
200 <P>
201 In the 8-bit library, strings are passed to PCRE library functions as vectors
202 of bytes with the C type "char *". In the 16-bit library, strings are passed as
203 vectors of unsigned 16-bit quantities. The macro PCRE_UCHAR16 specifies an
204 appropriate data type, and PCRE_SPTR16 is defined as "const PCRE_UCHAR16 *". In
205 very many environments, "short int" is a 16-bit data type. When PCRE is built,
206 it defines PCRE_UCHAR16 as "short int", but checks that it really is a 16-bit
207 data type. If it is not, the build fails with an error message telling the
208 maintainer to modify the definition appropriately.
209 </P>
210 <br><a name="SEC10" href="#TOC1">STRUCTURE TYPES</a><br>
211 <P>
212 The types of the opaque structures that are used for compiled 16-bit patterns
213 and JIT stacks are <b>pcre16</b> and <b>pcre16_jit_stack</b> respectively. The
214 type of the user-accessible structure that is returned by <b>pcre16_study()</b>
215 is <b>pcre16_extra</b>, and the type of the structure that is used for passing
216 data to a callout function is <b>pcre16_callout_block</b>. These structures
217 contain the same fields, with the same names, as their 8-bit counterparts. The
218 only difference is that pointers to character strings are 16-bit instead of
219 8-bit types.
220 </P>
221 <br><a name="SEC11" href="#TOC1">16-BIT FUNCTIONS</a><br>
222 <P>
223 For every function in the 8-bit library there is a corresponding function in
224 the 16-bit library with a name that starts with <b>pcre16_</b> instead of
225 <b>pcre_</b>. The prototypes are listed above. In addition, there is one extra
226 function, <b>pcre16_utf16_to_host_byte_order()</b>. This is a utility function
227 that converts a UTF-16 character string to host byte order if necessary. The
228 other 16-bit functions expect the strings they are passed to be in host byte
229 order.
230 </P>
231 <P>
232 The <i>input</i> and <i>output</i> arguments of
233 <b>pcre16_utf16_to_host_byte_order()</b> may point to the same address, that is,
234 conversion in place is supported. The output buffer must be at least as long as
235 the input.
236 </P>
237 <P>
238 The <i>length</i> argument specifies the number of 16-bit data units in the
239 input string; a negative value specifies a zero-terminated string.
240 </P>
241 <P>
242 If <i>byte_order</i> is NULL, it is assumed that the string starts off in host
243 byte order. This may be changed by byte-order marks (BOMs) anywhere in the
244 string (commonly as the first character).
245 </P>
246 <P>
247 If <i>byte_order</i> is not NULL, a non-zero value of the integer to which it
248 points means that the input starts off in host byte order, otherwise the
249 opposite order is assumed. Again, BOMs in the string can change this. The final
250 byte order is passed back at the end of processing.
251 </P>
252 <P>
253 If <i>keep_boms</i> is not zero, byte-order mark characters (0xfeff) are copied
254 into the output string. Otherwise they are discarded.
255 </P>
256 <P>
257 The result of the function is the number of 16-bit units placed into the output
258 buffer, including the zero terminator if the string was zero-terminated.
259 </P>
260 <br><a name="SEC12" href="#TOC1">SUBJECT STRING OFFSETS</a><br>
261 <P>
262 The offsets within subject strings that are returned by the matching functions
263 are in 16-bit units rather than bytes.
264 </P>
265 <br><a name="SEC13" href="#TOC1">NAMED SUBPATTERNS</a><br>
266 <P>
267 The name-to-number translation table that is maintained for named subpatterns
268 uses 16-bit characters. The <b>pcre16_get_stringtable_entries()</b> function
269 returns the length of each entry in the table as the number of 16-bit data
270 units.
271 </P>
272 <br><a name="SEC14" href="#TOC1">OPTION NAMES</a><br>
273 <P>
274 There are two new general option names, PCRE_UTF16 and PCRE_NO_UTF16_CHECK,
275 which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In
276 fact, these new options define the same bits in the options word. There is a
277 discussion about the
278 <a href="pcreunicode.html#utf16strings">validity of UTF-16 strings</a>
279 in the
280 <a href="pcreunicode.html"><b>pcreunicode</b></a>
281 page.
282 </P>
283 <P>
284 For the <b>pcre16_config()</b> function there is an option PCRE_CONFIG_UTF16
285 that returns 1 if UTF-16 support is configured, otherwise 0. If this option is
286 given to <b>pcre_config()</b> or <b>pcre32_config()</b>, or if the
287 PCRE_CONFIG_UTF8 or PCRE_CONFIG_UTF32 option is given to <b>pcre16_config()</b>,
288 the result is the PCRE_ERROR_BADOPTION error.
289 </P>
290 <br><a name="SEC15" href="#TOC1">CHARACTER CODES</a><br>
291 <P>
292 In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the
293 same way as in 8-bit, non UTF-8 mode, except, of course, that they can range
294 from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than
295 0xff can therefore be influenced by the locale in the same way as before.
296 Characters greater than 0xff have only one case, and no "type" (such as letter
297 or digit).
298 </P>
299 <P>
300 In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with
301 the exception of values in the range 0xd800 to 0xdfff because those are
302 "surrogate" values that are used in pairs to encode values greater than 0xffff.
303 </P>
304 <P>
305 A UTF-16 string can indicate its endianness by special code knows as a
306 byte-order mark (BOM). The PCRE functions do not handle this, expecting strings
307 to be in host byte order. A utility function called
308 <b>pcre16_utf16_to_host_byte_order()</b> is provided to help with this (see
309 above).
310 </P>
311 <br><a name="SEC16" href="#TOC1">ERROR NAMES</a><br>
312 <P>
313 The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to
314 their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled
315 pattern is passed to a function that processes patterns in the other
316 mode, for example, if a pattern compiled with <b>pcre_compile()</b> is passed to
317 <b>pcre16_exec()</b>.
318 </P>
319 <P>
320 There are new error codes whose names begin with PCRE_UTF16_ERR for invalid
321 UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that
322 are described in the section entitled
323 <a href="pcreapi.html#badutf8reasons">"Reason codes for invalid UTF-8 strings"</a>
324 in the main
325 <a href="pcreapi.html"><b>pcreapi</b></a>
326 page. The UTF-16 errors are:
327 <pre>
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 Non-character
332 </PRE>
333 </P>
334 <br><a name="SEC17" href="#TOC1">ERROR TEXTS</a><br>
335 <P>
336 If there is an error while compiling a pattern, the error text that is passed
337 back by <b>pcre16_compile()</b> or <b>pcre16_compile2()</b> is still an 8-bit
338 character string, zero-terminated.
339 </P>
340 <br><a name="SEC18" href="#TOC1">CALLOUTS</a><br>
341 <P>
342 The <i>subject</i> and <i>mark</i> fields in the callout block that is passed to
343 a callout function point to 16-bit vectors.
344 </P>
345 <br><a name="SEC19" href="#TOC1">TESTING</a><br>
346 <P>
347 The <b>pcretest</b> program continues to operate with 8-bit input and output
348 files, but it can be used for testing the 16-bit library. If it is run with the
349 command line option <b>-16</b>, patterns and subject strings are converted from
350 8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions
351 are used instead of the 8-bit ones. Returned 16-bit strings are converted to
352 8-bit for output. If both the 8-bit and the 32-bit libraries were not compiled,
353 <b>pcretest</b> defaults to 16-bit and the <b>-16</b> option is ignored.
354 </P>
355 <P>
356 When PCRE is being built, the <b>RunTest</b> script that is called by "make
357 check" uses the <b>pcretest</b> <b>-C</b> option to discover which of the 8-bit,
358 16-bit and 32-bit libraries has been built, and runs the tests appropriately.
359 </P>
360 <br><a name="SEC20" href="#TOC1">NOT SUPPORTED IN 16-BIT MODE</a><br>
361 <P>
362 Not all the features of the 8-bit library are available with the 16-bit
363 library. The C++ and POSIX wrapper functions support only the 8-bit library,
364 and the <b>pcregrep</b> program is at present 8-bit only.
365 </P>
366 <br><a name="SEC21" href="#TOC1">AUTHOR</a><br>
367 <P>
368 Philip Hazel
369 <br>
370 University Computing Service
371 <br>
372 Cambridge CB2 3QH, England.
373 <br>
374 </P>
375 <br><a name="SEC22" href="#TOC1">REVISION</a><br>
376 <P>
377 Last updated: 14 April 2012
378 <br>
379 Copyright &copy; 1997-2012 University of Cambridge.
380 <br>
381 <p>
382 Return to the <a href="index.html">PCRE index page</a>.
383 </p>

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