Annotation of embedaddon/pcre/doc/html/pcre16.html, revision 1.1.1.1

1.1       misho       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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