Annotation of embedaddon/pcre/doc/pcre16.3, revision 1.1.1.1

1.1       misho       1: .TH PCRE 3
                      2: .SH NAME
                      3: PCRE - Perl-compatible regular expressions
                      4: .sp
                      5: .B #include <pcre.h>
                      6: .
                      7: .
                      8: .SH "PCRE 16-BIT API BASIC FUNCTIONS"
                      9: .rs
                     10: .sp
                     11: .SM
                     12: .B pcre16 *pcre16_compile(PCRE_SPTR16 \fIpattern\fP, int \fIoptions\fP,
                     13: .ti +5n
                     14: .B const char **\fIerrptr\fP, int *\fIerroffset\fP,
                     15: .ti +5n
                     16: .B const unsigned char *\fItableptr\fP);
                     17: .PP
                     18: .B pcre16 *pcre16_compile2(PCRE_SPTR16 \fIpattern\fP, int \fIoptions\fP,
                     19: .ti +5n
                     20: .B int *\fIerrorcodeptr\fP,
                     21: .ti +5n
                     22: .B const char **\fIerrptr\fP, int *\fIerroffset\fP,
                     23: .ti +5n
                     24: .B const unsigned char *\fItableptr\fP);
                     25: .PP
                     26: .B pcre16_extra *pcre16_study(const pcre16 *\fIcode\fP, int \fIoptions\fP,
                     27: .ti +5n
                     28: .B const char **\fIerrptr\fP);
                     29: .PP
                     30: .B void pcre16_free_study(pcre16_extra *\fIextra\fP);
                     31: .PP
                     32: .B int pcre16_exec(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
                     33: .ti +5n
                     34: .B "PCRE_SPTR16 \fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
                     35: .ti +5n
                     36: .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);
                     37: .PP
                     38: .B int pcre16_dfa_exec(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
                     39: .ti +5n
                     40: .B "PCRE_SPTR16 \fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
                     41: .ti +5n
                     42: .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP,
                     43: .ti +5n
                     44: .B int *\fIworkspace\fP, int \fIwscount\fP);
                     45: .
                     46: .
                     47: .SH "PCRE 16-BIT API STRING EXTRACTION FUNCTIONS"
                     48: .rs
                     49: .sp
                     50: .B int pcre16_copy_named_substring(const pcre16 *\fIcode\fP,
                     51: .ti +5n
                     52: .B PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
                     53: .ti +5n
                     54: .B int \fIstringcount\fP, PCRE_SPTR16 \fIstringname\fP,
                     55: .ti +5n
                     56: .B PCRE_UCHAR16 *\fIbuffer\fP, int \fIbuffersize\fP);
                     57: .PP
                     58: .B int pcre16_copy_substring(PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
                     59: .ti +5n
                     60: .B int \fIstringcount\fP, int \fIstringnumber\fP, PCRE_UCHAR16 *\fIbuffer\fP,
                     61: .ti +5n
                     62: .B int \fIbuffersize\fP);
                     63: .PP
                     64: .B int pcre16_get_named_substring(const pcre16 *\fIcode\fP,
                     65: .ti +5n
                     66: .B PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
                     67: .ti +5n
                     68: .B int \fIstringcount\fP, PCRE_SPTR16 \fIstringname\fP,
                     69: .ti +5n
                     70: .B PCRE_SPTR16 *\fIstringptr\fP);
                     71: .PP
                     72: .B int pcre16_get_stringnumber(const pcre16 *\fIcode\fP,
                     73: .ti +5n
                     74: .B PCRE_SPTR16 \fIname\fP);
                     75: .PP
                     76: .B int pcre16_get_stringtable_entries(const pcre16 *\fIcode\fP,
                     77: .ti +5n
                     78: .B PCRE_SPTR16 \fIname\fP, PCRE_UCHAR16 **\fIfirst\fP, PCRE_UCHAR16 **\fIlast\fP);
                     79: .PP
                     80: .B int pcre16_get_substring(PCRE_SPTR16 \fIsubject\fP, int *\fIovector\fP,
                     81: .ti +5n
                     82: .B int \fIstringcount\fP, int \fIstringnumber\fP,
                     83: .ti +5n
                     84: .B PCRE_SPTR16 *\fIstringptr\fP);
                     85: .PP
                     86: .B int pcre16_get_substring_list(PCRE_SPTR16 \fIsubject\fP,
                     87: .ti +5n
                     88: .B int *\fIovector\fP, int \fIstringcount\fP, "PCRE_SPTR16 **\fIlistptr\fP);"
                     89: .PP
                     90: .B void pcre16_free_substring(PCRE_SPTR16 \fIstringptr\fP);
                     91: .PP
                     92: .B void pcre16_free_substring_list(PCRE_SPTR16 *\fIstringptr\fP);
                     93: .
                     94: .
                     95: .SH "PCRE 16-BIT API AUXILIARY FUNCTIONS"
                     96: .rs
                     97: .sp
                     98: .B pcre16_jit_stack *pcre16_jit_stack_alloc(int \fIstartsize\fP, int \fImaxsize\fP);
                     99: .PP
                    100: .B void pcre16_jit_stack_free(pcre16_jit_stack *\fIstack\fP);
                    101: .PP
                    102: .B void pcre16_assign_jit_stack(pcre16_extra *\fIextra\fP,
                    103: .ti +5n
                    104: .B pcre16_jit_callback \fIcallback\fP, void *\fIdata\fP);
                    105: .PP
                    106: .B const unsigned char *pcre16_maketables(void);
                    107: .PP
                    108: .B int pcre16_fullinfo(const pcre16 *\fIcode\fP, "const pcre16_extra *\fIextra\fP,"
                    109: .ti +5n
                    110: .B int \fIwhat\fP, void *\fIwhere\fP);
                    111: .PP
                    112: .B int pcre16_refcount(pcre16 *\fIcode\fP, int \fIadjust\fP);
                    113: .PP
                    114: .B int pcre16_config(int \fIwhat\fP, void *\fIwhere\fP);
                    115: .PP
                    116: .B const char *pcre16_version(void);
                    117: .PP
                    118: .B int pcre16_pattern_to_host_byte_order(pcre16 *\fIcode\fP,
                    119: .ti +5n
                    120: .B pcre16_extra *\fIextra\fP, const unsigned char *\fItables\fP);
                    121: .
                    122: .
                    123: .SH "PCRE 16-BIT API INDIRECTED FUNCTIONS"
                    124: .rs
                    125: .sp
                    126: .B void *(*pcre16_malloc)(size_t);
                    127: .PP
                    128: .B void (*pcre16_free)(void *);
                    129: .PP
                    130: .B void *(*pcre16_stack_malloc)(size_t);
                    131: .PP
                    132: .B void (*pcre16_stack_free)(void *);
                    133: .PP
                    134: .B int (*pcre16_callout)(pcre16_callout_block *);
                    135: .
                    136: .
                    137: .SH "PCRE 16-BIT API 16-BIT-ONLY FUNCTION"
                    138: .rs
                    139: .sp
                    140: .B int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *\fIoutput\fP,
                    141: .ti +5n
                    142: .B PCRE_SPTR16 \fIinput\fP, int \fIlength\fP, int *\fIbyte_order\fP,
                    143: .ti +5n
                    144: .B int \fIkeep_boms\fP);
                    145: .
                    146: .
                    147: .SH "THE PCRE 16-BIT LIBRARY"
                    148: .rs
                    149: .sp
                    150: Starting with release 8.30, it is possible to compile a PCRE library that
                    151: supports 16-bit character strings, including UTF-16 strings, as well as or
                    152: instead of the original 8-bit library. The majority of the work to make this
                    153: possible was done by Zoltan Herczeg. The two libraries contain identical sets
                    154: of functions, used in exactly the same way. Only the names of the functions and
                    155: the data types of their arguments and results are different. To avoid
                    156: over-complication and reduce the documentation maintenance load, most of the
                    157: PCRE documentation describes the 8-bit library, with only occasional references
                    158: to the 16-bit library. This page describes what is different when you use the
                    159: 16-bit library.
                    160: .P
                    161: WARNING: A single application can be linked with both libraries, but you must
                    162: take care when processing any particular pattern to use functions from just one
                    163: library. For example, if you want to study a pattern that was compiled with
                    164: \fBpcre16_compile()\fP, you must do so with \fBpcre16_study()\fP, not
                    165: \fBpcre_study()\fP, and you must free the study data with
                    166: \fBpcre16_free_study()\fP.
                    167: .
                    168: .
                    169: .SH "THE HEADER FILE"
                    170: .rs
                    171: .sp
                    172: There is only one header file, \fBpcre.h\fP. It contains prototypes for all the
                    173: functions in both libraries, as well as definitions of flags, structures, error
                    174: codes, etc.
                    175: .
                    176: .
                    177: .SH "THE LIBRARY NAME"
                    178: .rs
                    179: .sp
                    180: In Unix-like systems, the 16-bit library is called \fBlibpcre16\fP, and can
                    181: normally be accesss by adding \fB-lpcre16\fP to the command for linking an
                    182: application that uses PCRE.
                    183: .
                    184: .
                    185: .SH "STRING TYPES"
                    186: .rs
                    187: .sp
                    188: In the 8-bit library, strings are passed to PCRE library functions as vectors
                    189: of bytes with the C type "char *". In the 16-bit library, strings are passed as
                    190: vectors of unsigned 16-bit quantities. The macro PCRE_UCHAR16 specifies an
                    191: appropriate data type, and PCRE_SPTR16 is defined as "const PCRE_UCHAR16 *". In
                    192: very many environments, "short int" is a 16-bit data type. When PCRE is built,
                    193: it defines PCRE_UCHAR16 as "short int", but checks that it really is a 16-bit
                    194: data type. If it is not, the build fails with an error message telling the
                    195: maintainer to modify the definition appropriately.
                    196: .
                    197: .
                    198: .SH "STRUCTURE TYPES"
                    199: .rs
                    200: .sp
                    201: The types of the opaque structures that are used for compiled 16-bit patterns
                    202: and JIT stacks are \fBpcre16\fP and \fBpcre16_jit_stack\fP respectively. The
                    203: type of the user-accessible structure that is returned by \fBpcre16_study()\fP
                    204: is \fBpcre16_extra\fP, and the type of the structure that is used for passing
                    205: data to a callout function is \fBpcre16_callout_block\fP. These structures
                    206: contain the same fields, with the same names, as their 8-bit counterparts. The
                    207: only difference is that pointers to character strings are 16-bit instead of
                    208: 8-bit types.
                    209: .
                    210: .
                    211: .SH "16-BIT FUNCTIONS"
                    212: .rs
                    213: .sp
                    214: For every function in the 8-bit library there is a corresponding function in
                    215: the 16-bit library with a name that starts with \fBpcre16_\fP instead of
                    216: \fBpcre_\fP. The prototypes are listed above. In addition, there is one extra
                    217: function, \fBpcre16_utf16_to_host_byte_order()\fP. This is a utility function
                    218: that converts a UTF-16 character string to host byte order if necessary. The
                    219: other 16-bit functions expect the strings they are passed to be in host byte
                    220: order.
                    221: .P
                    222: The \fIinput\fP and \fIoutput\fP arguments of
                    223: \fBpcre16_utf16_to_host_byte_order()\fP may point to the same address, that is,
                    224: conversion in place is supported. The output buffer must be at least as long as
                    225: the input.
                    226: .P
                    227: The \fIlength\fP argument specifies the number of 16-bit data units in the
                    228: input string; a negative value specifies a zero-terminated string.
                    229: .P
                    230: If \fIbyte_order\fP is NULL, it is assumed that the string starts off in host
                    231: byte order. This may be changed by byte-order marks (BOMs) anywhere in the
                    232: string (commonly as the first character).
                    233: .P
                    234: If \fIbyte_order\fP is not NULL, a non-zero value of the integer to which it
                    235: points means that the input starts off in host byte order, otherwise the
                    236: opposite order is assumed. Again, BOMs in the string can change this. The final
                    237: byte order is passed back at the end of processing.
                    238: .P
                    239: If \fIkeep_boms\fP is not zero, byte-order mark characters (0xfeff) are copied
                    240: into the output string. Otherwise they are discarded.
                    241: .P
                    242: The result of the function is the number of 16-bit units placed into the output
                    243: buffer, including the zero terminator if the string was zero-terminated.
                    244: .
                    245: .
                    246: .SH "SUBJECT STRING OFFSETS"
                    247: .rs
                    248: .sp
                    249: The offsets within subject strings that are returned by the matching functions
                    250: are in 16-bit units rather than bytes.
                    251: .
                    252: .
                    253: .SH "NAMED SUBPATTERNS"
                    254: .rs
                    255: .sp
                    256: The name-to-number translation table that is maintained for named subpatterns
                    257: uses 16-bit characters. The \fBpcre16_get_stringtable_entries()\fP function
                    258: returns the length of each entry in the table as the number of 16-bit data
                    259: units.
                    260: .
                    261: .
                    262: .SH "OPTION NAMES"
                    263: .rs
                    264: .sp
                    265: There are two new general option names, PCRE_UTF16 and PCRE_NO_UTF16_CHECK,
                    266: which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In
                    267: fact, these new options define the same bits in the options word.
                    268: .P
                    269: For the \fBpcre16_config()\fP function there is an option PCRE_CONFIG_UTF16
                    270: that returns 1 if UTF-16 support is configured, otherwise 0. If this option is
                    271: given to \fBpcre_config()\fP, or if the PCRE_CONFIG_UTF8 option is given to
                    272: \fBpcre16_config()\fP, the result is the PCRE_ERROR_BADOPTION error.
                    273: .
                    274: .
                    275: .SH "CHARACTER CODES"
                    276: .rs
                    277: .sp
                    278: In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the
                    279: same way as in 8-bit, non UTF-8 mode, except, of course, that they can range
                    280: from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than
                    281: 0xff can therefore be influenced by the locale in the same way as before.
                    282: Characters greater than 0xff have only one case, and no "type" (such as letter
                    283: or digit).
                    284: .P
                    285: In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with
                    286: the exception of values in the range 0xd800 to 0xdfff because those are
                    287: "surrogate" values that are used in pairs to encode values greater than 0xffff.
                    288: .P
                    289: A UTF-16 string can indicate its endianness by special code knows as a
                    290: byte-order mark (BOM). The PCRE functions do not handle this, expecting strings
                    291: to be in host byte order. A utility function called
                    292: \fBpcre16_utf16_to_host_byte_order()\fP is provided to help with this (see
                    293: above).
                    294: .
                    295: .
                    296: .SH "ERROR NAMES"
                    297: .rs
                    298: .sp
                    299: The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to
                    300: their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled
                    301: pattern is passed to a function that processes patterns in the other
                    302: mode, for example, if a pattern compiled with \fBpcre_compile()\fP is passed to
                    303: \fBpcre16_exec()\fP.
                    304: .P
                    305: There are new error codes whose names begin with PCRE_UTF16_ERR for invalid
                    306: UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that
                    307: are described in the section entitled
                    308: .\" HTML <a href="pcreapi.html#badutf8reasons">
                    309: .\" </a>
                    310: "Reason codes for invalid UTF-8 strings"
                    311: .\"
                    312: in the main
                    313: .\" HREF
                    314: \fBpcreapi\fP
                    315: .\"
                    316: page. The UTF-16 errors are:
                    317: .sp
                    318:   PCRE_UTF16_ERR1  Missing low surrogate at end of string
                    319:   PCRE_UTF16_ERR2  Invalid low surrogate follows high surrogate
                    320:   PCRE_UTF16_ERR3  Isolated low surrogate
                    321:   PCRE_UTF16_ERR4  Invalid character 0xfffe
                    322: .
                    323: .
                    324: .SH "ERROR TEXTS"
                    325: .rs
                    326: .sp
                    327: If there is an error while compiling a pattern, the error text that is passed
                    328: back by \fBpcre16_compile()\fP or \fBpcre16_compile2()\fP is still an 8-bit
                    329: character string, zero-terminated.
                    330: .
                    331: .
                    332: .SH "CALLOUTS"
                    333: .rs
                    334: .sp
                    335: The \fIsubject\fP and \fImark\fP fields in the callout block that is passed to
                    336: a callout function point to 16-bit vectors.
                    337: .
                    338: .
                    339: .SH "TESTING"
                    340: .rs
                    341: .sp
                    342: The \fBpcretest\fP program continues to operate with 8-bit input and output
                    343: files, but it can be used for testing the 16-bit library. If it is run with the
                    344: command line option \fB-16\fP, patterns and subject strings are converted from
                    345: 8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions
                    346: are used instead of the 8-bit ones. Returned 16-bit strings are converted to
                    347: 8-bit for output. If the 8-bit library was not compiled, \fBpcretest\fP
                    348: defaults to 16-bit and the \fB-16\fP option is ignored.
                    349: .P
                    350: When PCRE is being built, the \fBRunTest\fP script that is called by "make
                    351: check" uses the \fBpcretest\fP \fB-C\fP option to discover which of the 8-bit
                    352: and 16-bit libraries has been built, and runs the tests appropriately.
                    353: .
                    354: .
                    355: .SH "NOT SUPPORTED IN 16-BIT MODE"
                    356: .rs
                    357: .sp
                    358: Not all the features of the 8-bit library are available with the 16-bit
                    359: library. The C++ and POSIX wrapper functions support only the 8-bit library,
                    360: and the \fBpcregrep\fP program is at present 8-bit only.
                    361: .
                    362: .
                    363: .SH AUTHOR
                    364: .rs
                    365: .sp
                    366: .nf
                    367: Philip Hazel
                    368: University Computing Service
                    369: Cambridge CB2 3QH, England.
                    370: .fi
                    371: .
                    372: .
                    373: .SH REVISION
                    374: .rs
                    375: .sp
                    376: .nf
                    377: Last updated: 08 January 2012
                    378: Copyright (c) 1997-2012 University of Cambridge.
                    379: .fi

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