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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.
277    </P>
278    <P>
279    For the <b>pcre16_config()</b> 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 <b>pcre_config()</b>, or if the PCRE_CONFIG_UTF8 option is given to
282    <b>pcre16_config()</b>, the result is the PCRE_ERROR_BADOPTION error.
283    </P>
284    <br><a name="SEC15" href="#TOC1">CHARACTER CODES</a><br>
285    <P>
286    In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the
287    same way as in 8-bit, non UTF-8 mode, except, of course, that they can range
288    from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than
289    0xff can therefore be influenced by the locale in the same way as before.
290    Characters greater than 0xff have only one case, and no "type" (such as letter
291    or digit).
292    </P>
293    <P>
294    In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with
295    the exception of values in the range 0xd800 to 0xdfff because those are
296    "surrogate" values that are used in pairs to encode values greater than 0xffff.
297    </P>
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    <b>pcre16_utf16_to_host_byte_order()</b> is provided to help with this (see
303    above).
304    </P>
305    <br><a name="SEC16" href="#TOC1">ERROR NAMES</a><br>
306    <P>
307    The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to
308    their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled
309    pattern is passed to a function that processes patterns in the other
310    mode, for example, if a pattern compiled with <b>pcre_compile()</b> is passed to
311    <b>pcre16_exec()</b>.
312    </P>
313    <P>
314    There are new error codes whose names begin with PCRE_UTF16_ERR for invalid
315    UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that
316    are described in the section entitled
317    <a href="pcreapi.html#badutf8reasons">"Reason codes for invalid UTF-8 strings"</a>
318    in the main
319    <a href="pcreapi.html"><b>pcreapi</b></a>
320    page. The UTF-16 errors are:
321    <pre>
322      PCRE_UTF16_ERR1  Missing low surrogate at end of string
323      PCRE_UTF16_ERR2  Invalid low surrogate follows high surrogate
324      PCRE_UTF16_ERR3  Isolated low surrogate
325      PCRE_UTF16_ERR4  Invalid character 0xfffe
326    </PRE>
327    </P>
328    <br><a name="SEC17" href="#TOC1">ERROR TEXTS</a><br>
329    <P>
330    If there is an error while compiling a pattern, the error text that is passed
331    back by <b>pcre16_compile()</b> or <b>pcre16_compile2()</b> is still an 8-bit
332    character string, zero-terminated.
333    </P>
334    <br><a name="SEC18" href="#TOC1">CALLOUTS</a><br>
335    <P>
336    The <i>subject</i> and <i>mark</i> fields in the callout block that is passed to
337    a callout function point to 16-bit vectors.
338    </P>
339    <br><a name="SEC19" href="#TOC1">TESTING</a><br>
340    <P>
341    The <b>pcretest</b> program continues to operate with 8-bit input and output
342    files, but it can be used for testing the 16-bit library. If it is run with the
343    command line option <b>-16</b>, patterns and subject strings are converted from
344    8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions
345    are used instead of the 8-bit ones. Returned 16-bit strings are converted to
346    8-bit for output. If the 8-bit library was not compiled, <b>pcretest</b>
347    defaults to 16-bit and the <b>-16</b> option is ignored.
348    </P>
349    <P>
350    When PCRE is being built, the <b>RunTest</b> script that is called by "make
351    check" uses the <b>pcretest</b> <b>-C</b> option to discover which of the 8-bit
352    and 16-bit libraries has been built, and runs the tests appropriately.
353    </P>
354    <br><a name="SEC20" href="#TOC1">NOT SUPPORTED IN 16-BIT MODE</a><br>
355    <P>
356    Not all the features of the 8-bit library are available with the 16-bit
357    library. The C++ and POSIX wrapper functions support only the 8-bit library,
358    and the <b>pcregrep</b> program is at present 8-bit only.
359    </P>
360    <br><a name="SEC21" href="#TOC1">AUTHOR</a><br>
361    <P>
362    Philip Hazel
363    <br>
364    University Computing Service
365    <br>
366    Cambridge CB2 3QH, England.
367    <br>
368    </P>
369    <br><a name="SEC22" href="#TOC1">REVISION</a><br>
370    <P>
371    Last updated: 08 January 2012
372    <br>
373    Copyright &copy; 1997-2012 University of Cambridge.
374    <br>
375    <p>
376    Return to the <a href="index.html">PCRE index page</a>.
377    </p>

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