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> 8Return to the <a href="index.html">PCRE index page</a>. 9</p> 10<p> 11This page is part of the PCRE HTML documentation. It was generated automatically 12from the original man page. If there is any nonsense in it, please consult the 13man 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 <pcre.h></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> 168Starting with release 8.30, it is possible to compile a PCRE library that 169supports 16-bit character strings, including UTF-16 strings, as well as or 170instead of the original 8-bit library. The majority of the work to make this 171possible was done by Zoltan Herczeg. The two libraries contain identical sets 172of functions, used in exactly the same way. Only the names of the functions and 173the data types of their arguments and results are different. To avoid 174over-complication and reduce the documentation maintenance load, most of the 175PCRE documentation describes the 8-bit library, with only occasional references 176to the 16-bit library. This page describes what is different when you use the 17716-bit library. 178</P> 179<P> 180WARNING: A single application can be linked with both libraries, but you must 181take care when processing any particular pattern to use functions from just one 182library. 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> 189There is only one header file, <b>pcre.h</b>. It contains prototypes for all the 190functions in both libraries, as well as definitions of flags, structures, error 191codes, etc. 192</P> 193<br><a name="SEC8" href="#TOC1">THE LIBRARY NAME</a><br> 194<P> 195In Unix-like systems, the 16-bit library is called <b>libpcre16</b>, and can 196normally be accesss by adding <b>-lpcre16</b> to the command for linking an 197application that uses PCRE. 198</P> 199<br><a name="SEC9" href="#TOC1">STRING TYPES</a><br> 200<P> 201In the 8-bit library, strings are passed to PCRE library functions as vectors 202of bytes with the C type "char *". In the 16-bit library, strings are passed as 203vectors of unsigned 16-bit quantities. The macro PCRE_UCHAR16 specifies an 204appropriate data type, and PCRE_SPTR16 is defined as "const PCRE_UCHAR16 *". In 205very many environments, "short int" is a 16-bit data type. When PCRE is built, 206it defines PCRE_UCHAR16 as "short int", but checks that it really is a 16-bit 207data type. If it is not, the build fails with an error message telling the 208maintainer to modify the definition appropriately. 209</P> 210<br><a name="SEC10" href="#TOC1">STRUCTURE TYPES</a><br> 211<P> 212The types of the opaque structures that are used for compiled 16-bit patterns 213and JIT stacks are <b>pcre16</b> and <b>pcre16_jit_stack</b> respectively. The 214type of the user-accessible structure that is returned by <b>pcre16_study()</b> 215is <b>pcre16_extra</b>, and the type of the structure that is used for passing 216data to a callout function is <b>pcre16_callout_block</b>. These structures 217contain the same fields, with the same names, as their 8-bit counterparts. The 218only difference is that pointers to character strings are 16-bit instead of 2198-bit types. 220</P> 221<br><a name="SEC11" href="#TOC1">16-BIT FUNCTIONS</a><br> 222<P> 223For every function in the 8-bit library there is a corresponding function in 224the 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 226function, <b>pcre16_utf16_to_host_byte_order()</b>. This is a utility function 227that converts a UTF-16 character string to host byte order if necessary. The 228other 16-bit functions expect the strings they are passed to be in host byte 229order. 230</P> 231<P> 232The <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, 234conversion in place is supported. The output buffer must be at least as long as 235the input. 236</P> 237<P> 238The <i>length</i> argument specifies the number of 16-bit data units in the 239input string; a negative value specifies a zero-terminated string. 240</P> 241<P> 242If <i>byte_order</i> is NULL, it is assumed that the string starts off in host 243byte order. This may be changed by byte-order marks (BOMs) anywhere in the 244string (commonly as the first character). 245</P> 246<P> 247If <i>byte_order</i> is not NULL, a non-zero value of the integer to which it 248points means that the input starts off in host byte order, otherwise the 249opposite order is assumed. Again, BOMs in the string can change this. The final 250byte order is passed back at the end of processing. 251</P> 252<P> 253If <i>keep_boms</i> is not zero, byte-order mark characters (0xfeff) are copied 254into the output string. Otherwise they are discarded. 255</P> 256<P> 257The result of the function is the number of 16-bit units placed into the output 258buffer, 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> 262The offsets within subject strings that are returned by the matching functions 263are in 16-bit units rather than bytes. 264</P> 265<br><a name="SEC13" href="#TOC1">NAMED SUBPATTERNS</a><br> 266<P> 267The name-to-number translation table that is maintained for named subpatterns 268uses 16-bit characters. The <b>pcre16_get_stringtable_entries()</b> function 269returns the length of each entry in the table as the number of 16-bit data 270units. 271</P> 272<br><a name="SEC14" href="#TOC1">OPTION NAMES</a><br> 273<P> 274There are two new general option names, PCRE_UTF16 and PCRE_NO_UTF16_CHECK, 275which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In 276fact, these new options define the same bits in the options word. There is a 277discussion about the 278<a href="pcreunicode.html#utf16strings">validity of UTF-16 strings</a> 279in the 280<a href="pcreunicode.html"><b>pcreunicode</b></a> 281page. 282</P> 283<P> 284For the <b>pcre16_config()</b> function there is an option PCRE_CONFIG_UTF16 285that returns 1 if UTF-16 support is configured, otherwise 0. If this option is 286given to <b>pcre_config()</b>, or if the PCRE_CONFIG_UTF8 option is given to 287<b>pcre16_config()</b>, the result is the PCRE_ERROR_BADOPTION error. 288</P> 289<br><a name="SEC15" href="#TOC1">CHARACTER CODES</a><br> 290<P> 291In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the 292same way as in 8-bit, non UTF-8 mode, except, of course, that they can range 293from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than 2940xff can therefore be influenced by the locale in the same way as before. 295Characters greater than 0xff have only one case, and no "type" (such as letter 296or digit). 297</P> 298<P> 299In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with 300the exception of values in the range 0xd800 to 0xdfff because those are 301"surrogate" values that are used in pairs to encode values greater than 0xffff. 302</P> 303<P> 304A UTF-16 string can indicate its endianness by special code knows as a 305byte-order mark (BOM). The PCRE functions do not handle this, expecting strings 306to be in host byte order. A utility function called 307<b>pcre16_utf16_to_host_byte_order()</b> is provided to help with this (see 308above). 309</P> 310<br><a name="SEC16" href="#TOC1">ERROR NAMES</a><br> 311<P> 312The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to 313their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled 314pattern is passed to a function that processes patterns in the other 315mode, for example, if a pattern compiled with <b>pcre_compile()</b> is passed to 316<b>pcre16_exec()</b>. 317</P> 318<P> 319There are new error codes whose names begin with PCRE_UTF16_ERR for invalid 320UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that 321are described in the section entitled 322<a href="pcreapi.html#badutf8reasons">"Reason codes for invalid UTF-8 strings"</a> 323in the main 324<a href="pcreapi.html"><b>pcreapi</b></a> 325page. The UTF-16 errors are: 326<pre> 327 PCRE_UTF16_ERR1 Missing low surrogate at end of string 328 PCRE_UTF16_ERR2 Invalid low surrogate follows high surrogate 329 PCRE_UTF16_ERR3 Isolated low surrogate 330 PCRE_UTF16_ERR4 Invalid character 0xfffe 331</PRE> 332</P> 333<br><a name="SEC17" href="#TOC1">ERROR TEXTS</a><br> 334<P> 335If there is an error while compiling a pattern, the error text that is passed 336back by <b>pcre16_compile()</b> or <b>pcre16_compile2()</b> is still an 8-bit 337character string, zero-terminated. 338</P> 339<br><a name="SEC18" href="#TOC1">CALLOUTS</a><br> 340<P> 341The <i>subject</i> and <i>mark</i> fields in the callout block that is passed to 342a callout function point to 16-bit vectors. 343</P> 344<br><a name="SEC19" href="#TOC1">TESTING</a><br> 345<P> 346The <b>pcretest</b> program continues to operate with 8-bit input and output 347files, but it can be used for testing the 16-bit library. If it is run with the 348command line option <b>-16</b>, patterns and subject strings are converted from 3498-bit to 16-bit before being passed to PCRE, and the 16-bit library functions 350are used instead of the 8-bit ones. Returned 16-bit strings are converted to 3518-bit for output. If the 8-bit library was not compiled, <b>pcretest</b> 352defaults to 16-bit and the <b>-16</b> option is ignored. 353</P> 354<P> 355When PCRE is being built, the <b>RunTest</b> script that is called by "make 356check" uses the <b>pcretest</b> <b>-C</b> option to discover which of the 8-bit 357and 16-bit libraries has been built, and runs the tests appropriately. 358</P> 359<br><a name="SEC20" href="#TOC1">NOT SUPPORTED IN 16-BIT MODE</a><br> 360<P> 361Not all the features of the 8-bit library are available with the 16-bit 362library. The C++ and POSIX wrapper functions support only the 8-bit library, 363and the <b>pcregrep</b> program is at present 8-bit only. 364</P> 365<br><a name="SEC21" href="#TOC1">AUTHOR</a><br> 366<P> 367Philip Hazel 368<br> 369University Computing Service 370<br> 371Cambridge CB2 3QH, England. 372<br> 373</P> 374<br><a name="SEC22" href="#TOC1">REVISION</a><br> 375<P> 376Last updated: 14 April 2012 377<br> 378Copyright © 1997-2012 University of Cambridge. 379<br> 380<p> 381Return to the <a href="index.html">PCRE index page</a>. 382</p> 383