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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:  8: Return to the <a href="index.html">PCRE index page</a>. 9:  10:  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:   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:  40: #include <pcre.h> 41:  42:  <a name="SEC1" href="#TOC1">PCRE 16-BIT API BASIC FUNCTIONS</a>  43:  44: pcre16 *pcre16_compile(PCRE_SPTR16 pattern, int options, 45: const char **errptr, int *erroffset, 46: const unsigned char *tableptr); 47:  48:  49: pcre16 *pcre16_compile2(PCRE_SPTR16 pattern, int options, 50: int *errorcodeptr, 51: const char **errptr, int *erroffset, 52: const unsigned char *tableptr); 53:  54:  55: pcre16_extra *pcre16_study(const pcre16 *code, int options, 56: const char **errptr); 57:  58:  59: void pcre16_free_study(pcre16_extra *extra); 60:  61:  62: int pcre16_exec(const pcre16 *code, const pcre16_extra *extra, 63: PCRE_SPTR16 subject, int length, int startoffset, 64: int options, int *ovector, int ovecsize); 65:  66:  67: int pcre16_dfa_exec(const pcre16 *code, const pcre16_extra *extra, 68: PCRE_SPTR16 subject, int length, int startoffset, 69: int options, int *ovector, int ovecsize, 70: int *workspace, int wscount); 71:  72:  <a name="SEC2" href="#TOC1">PCRE 16-BIT API STRING EXTRACTION FUNCTIONS</a>  73:  74: int pcre16_copy_named_substring(const pcre16 *code, 75: PCRE_SPTR16 subject, int *ovector, 76: int stringcount, PCRE_SPTR16 stringname, 77: PCRE_UCHAR16 *buffer, int buffersize); 78:  79:  80: int pcre16_copy_substring(PCRE_SPTR16 subject, int *ovector, 81: int stringcount, int stringnumber, PCRE_UCHAR16 *buffer, 82: int buffersize); 83:  84:  85: int pcre16_get_named_substring(const pcre16 *code, 86: PCRE_SPTR16 subject, int *ovector, 87: int stringcount, PCRE_SPTR16 stringname, 88: PCRE_SPTR16 *stringptr); 89:  90:  91: int pcre16_get_stringnumber(const pcre16 *code, 92: PCRE_SPTR16 name); 93:  94:  95: int pcre16_get_stringtable_entries(const pcre16 *code, 96: PCRE_SPTR16 name, PCRE_UCHAR16 **first, PCRE_UCHAR16 **last); 97:  98:  99: int pcre16_get_substring(PCRE_SPTR16 subject, int *ovector, 100: int stringcount, int stringnumber, 101: PCRE_SPTR16 *stringptr); 102:  103:  104: int pcre16_get_substring_list(PCRE_SPTR16 subject, 105: int *ovector, int stringcount, PCRE_SPTR16 **listptr); 106:  107:  108: void pcre16_free_substring(PCRE_SPTR16 stringptr); 109:  110:  111: void pcre16_free_substring_list(PCRE_SPTR16 *stringptr); 112:  113:  <a name="SEC3" href="#TOC1">PCRE 16-BIT API AUXILIARY FUNCTIONS</a>  114:  115: pcre16_jit_stack *pcre16_jit_stack_alloc(int startsize, int maxsize); 116:  117:  118: void pcre16_jit_stack_free(pcre16_jit_stack *stack); 119:  120:  121: void pcre16_assign_jit_stack(pcre16_extra *extra, 122: pcre16_jit_callback callback, void *data); 123:  124:  125: const unsigned char *pcre16_maketables(void); 126:  127:  128: int pcre16_fullinfo(const pcre16 *code, const pcre16_extra *extra, 129: int what, void *where); 130:  131:  132: int pcre16_refcount(pcre16 *code, int adjust); 133:  134:  135: int pcre16_config(int what, void *where); 136:  137:  138: const char *pcre16_version(void); 139:  140:  141: int pcre16_pattern_to_host_byte_order(pcre16 *code, 142: pcre16_extra *extra, const unsigned char *tables); 143:  144:  <a name="SEC4" href="#TOC1">PCRE 16-BIT API INDIRECTED FUNCTIONS</a>  145:  146: void *(*pcre16_malloc)(size_t); 147:  148:  149: void (*pcre16_free)(void *); 150:  151:  152: void *(*pcre16_stack_malloc)(size_t); 153:  154:  155: void (*pcre16_stack_free)(void *); 156:  157:  158: int (*pcre16_callout)(pcre16_callout_block *); 159:  160:  <a name="SEC5" href="#TOC1">PCRE 16-BIT API 16-BIT-ONLY FUNCTION</a>  161:  162: int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *output, 163: PCRE_SPTR16 input, int length, int *byte_order, 164: int keep_boms); 165:  166:  <a name="SEC6" href="#TOC1">THE PCRE 16-BIT LIBRARY</a>  167:  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:  179:  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: pcre16_compile(), you must do so with pcre16_study(), not 184: pcre_study(), and you must free the study data with 185: pcre16_free_study(). 186:  187:  <a name="SEC7" href="#TOC1">THE HEADER FILE</a>  188:  189: There is only one header file, pcre.h. It contains prototypes for all the 190: functions in all libraries, as well as definitions of flags, structures, error 191: codes, etc. 192:  193:  <a name="SEC8" href="#TOC1">THE LIBRARY NAME</a>  194:  195: In Unix-like systems, the 16-bit library is called libpcre16, and can 196: normally be accesss by adding -lpcre16 to the command for linking an 197: application that uses PCRE. 198:  199:  <a name="SEC9" href="#TOC1">STRING TYPES</a>  200:  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 "unsigned short int", but checks that it really is a 207: 16-bit data type. If it is not, the build fails with an error message telling 208: the maintainer to modify the definition appropriately. 209:  210:  <a name="SEC10" href="#TOC1">STRUCTURE TYPES</a>  211:  212: The types of the opaque structures that are used for compiled 16-bit patterns 213: and JIT stacks are pcre16 and pcre16_jit_stack respectively. The 214: type of the user-accessible structure that is returned by pcre16_study() 215: is pcre16_extra, and the type of the structure that is used for passing 216: data to a callout function is pcre16_callout_block. 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:  221:  <a name="SEC11" href="#TOC1">16-BIT FUNCTIONS</a>  222:  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 pcre16_ instead of 225: pcre_. The prototypes are listed above. In addition, there is one extra 226: function, pcre16_utf16_to_host_byte_order(). 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:  231:  232: The input and output arguments of 233: pcre16_utf16_to_host_byte_order() 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:  237:  238: The length argument specifies the number of 16-bit data units in the 239: input string; a negative value specifies a zero-terminated string. 240:  241:  242: If byte_order 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:  246:  247: If byte_order 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:  252:  253: If keep_boms is not zero, byte-order mark characters (0xfeff) are copied 254: into the output string. Otherwise they are discarded. 255:  256:  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:  260:  <a name="SEC12" href="#TOC1">SUBJECT STRING OFFSETS</a>  261:  262: The lengths and starting offsets of subject strings must be specified in 16-bit 263: data units, and the offsets within subject strings that are returned by the 264: matching functions are in also 16-bit units rather than bytes. 265:  266:  <a name="SEC13" href="#TOC1">NAMED SUBPATTERNS</a>  267:  268: The name-to-number translation table that is maintained for named subpatterns 269: uses 16-bit characters. The pcre16_get_stringtable_entries() function 270: returns the length of each entry in the table as the number of 16-bit data 271: units. 272:  273:  <a name="SEC14" href="#TOC1">OPTION NAMES</a>  274:  275: There are two new general option names, PCRE_UTF16 and PCRE_NO_UTF16_CHECK, 276: which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In 277: fact, these new options define the same bits in the options word. There is a 278: discussion about the 279: <a href="pcreunicode.html#utf16strings">validity of UTF-16 strings</a> 280: in the 281: <a href="pcreunicode.html">pcreunicode</a> 282: page. 283:  284:  285: For the pcre16_config() function there is an option PCRE_CONFIG_UTF16 286: that returns 1 if UTF-16 support is configured, otherwise 0. If this option is 287: given to pcre_config() or pcre32_config(), or if the 288: PCRE_CONFIG_UTF8 or PCRE_CONFIG_UTF32 option is given to pcre16_config(), 289: the result is the PCRE_ERROR_BADOPTION error. 290:  291:  <a name="SEC15" href="#TOC1">CHARACTER CODES</a>  292:  293: In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the 294: same way as in 8-bit, non UTF-8 mode, except, of course, that they can range 295: from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than 296: 0xff can therefore be influenced by the locale in the same way as before. 297: Characters greater than 0xff have only one case, and no "type" (such as letter 298: or digit). 299:  300:  301: In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with 302: the exception of values in the range 0xd800 to 0xdfff because those are 303: "surrogate" values that are used in pairs to encode values greater than 0xffff. 304:  305:  306: A UTF-16 string can indicate its endianness by special code knows as a 307: byte-order mark (BOM). The PCRE functions do not handle this, expecting strings 308: to be in host byte order. A utility function called 309: pcre16_utf16_to_host_byte_order() is provided to help with this (see 310: above). 311:  312:  <a name="SEC16" href="#TOC1">ERROR NAMES</a>  313:  314: The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to 315: their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled 316: pattern is passed to a function that processes patterns in the other 317: mode, for example, if a pattern compiled with pcre_compile() is passed to 318: pcre16_exec(). 319:  320:  321: There are new error codes whose names begin with PCRE_UTF16_ERR for invalid 322: UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that 323: are described in the section entitled 324: <a href="pcreapi.html#badutf8reasons">"Reason codes for invalid UTF-8 strings"</a> 325: in the main 326: <a href="pcreapi.html">pcreapi</a> 327: page. The UTF-16 errors are: 328: <pre> 329: PCRE_UTF16_ERR1 Missing low surrogate at end of string 330: PCRE_UTF16_ERR2 Invalid low surrogate follows high surrogate 331: PCRE_UTF16_ERR3 Isolated low surrogate 332: PCRE_UTF16_ERR4 Non-character 333: </PRE> 334:  335:  <a name="SEC17" href="#TOC1">ERROR TEXTS</a>  336:  337: If there is an error while compiling a pattern, the error text that is passed 338: back by pcre16_compile() or pcre16_compile2() is still an 8-bit 339: character string, zero-terminated. 340:  341:  <a name="SEC18" href="#TOC1">CALLOUTS</a>  342:  343: The subject and mark fields in the callout block that is passed to 344: a callout function point to 16-bit vectors. 345:  346:  <a name="SEC19" href="#TOC1">TESTING</a>  347:  348: The pcretest program continues to operate with 8-bit input and output 349: files, but it can be used for testing the 16-bit library. If it is run with the 350: command line option -16, patterns and subject strings are converted from 351: 8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions 352: are used instead of the 8-bit ones. Returned 16-bit strings are converted to 353: 8-bit for output. If both the 8-bit and the 32-bit libraries were not compiled, 354: pcretest defaults to 16-bit and the -16 option is ignored. 355:  356:  357: When PCRE is being built, the RunTest script that is called by "make 358: check" uses the pcretest -C option to discover which of the 8-bit, 359: 16-bit and 32-bit libraries has been built, and runs the tests appropriately. 360:  361:  <a name="SEC20" href="#TOC1">NOT SUPPORTED IN 16-BIT MODE</a>  362:  363: Not all the features of the 8-bit library are available with the 16-bit 364: library. The C++ and POSIX wrapper functions support only the 8-bit library, 365: and the pcregrep program is at present 8-bit only. 366:  367:  <a name="SEC21" href="#TOC1">AUTHOR</a>  368:  369: Philip Hazel 370:   371: University Computing Service 372:   373: Cambridge CB2 3QH, England. 374:   375:  376:  <a name="SEC22" href="#TOC1">REVISION</a>  377:  378: Last updated: 12 May 2013 379:   380: Copyright © 1997-2013 University of Cambridge. 381:   382:  383: Return to the <a href="index.html">PCRE index page</a>. 384: 