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pcre

    1: .TH PCRE 3 "14 April 2012" "PCRE 8.31"
    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. There is a
  268: discussion about the
  269: .\" HTML <a href="pcreunicode.html#utf16strings">
  270: .\" </a>
  271: validity of UTF-16 strings
  272: .\"
  273: in the
  274: .\" HREF
  275: \fBpcreunicode\fP
  276: .\"
  277: page.
  278: .P
  279: For the \fBpcre16_config()\fP 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 \fBpcre_config()\fP, or if the PCRE_CONFIG_UTF8 option is given to
  282: \fBpcre16_config()\fP, the result is the PCRE_ERROR_BADOPTION error.
  283: .
  284: .
  285: .SH "CHARACTER CODES"
  286: .rs
  287: .sp
  288: In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the
  289: same way as in 8-bit, non UTF-8 mode, except, of course, that they can range
  290: from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than
  291: 0xff can therefore be influenced by the locale in the same way as before.
  292: Characters greater than 0xff have only one case, and no "type" (such as letter
  293: or digit).
  294: .P
  295: In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with
  296: the exception of values in the range 0xd800 to 0xdfff because those are
  297: "surrogate" values that are used in pairs to encode values greater than 0xffff.
  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: \fBpcre16_utf16_to_host_byte_order()\fP is provided to help with this (see
  303: above).
  304: .
  305: .
  306: .SH "ERROR NAMES"
  307: .rs
  308: .sp
  309: The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to
  310: their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled
  311: pattern is passed to a function that processes patterns in the other
  312: mode, for example, if a pattern compiled with \fBpcre_compile()\fP is passed to
  313: \fBpcre16_exec()\fP.
  314: .P
  315: There are new error codes whose names begin with PCRE_UTF16_ERR for invalid
  316: UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that
  317: are described in the section entitled
  318: .\" HTML <a href="pcreapi.html#badutf8reasons">
  319: .\" </a>
  320: "Reason codes for invalid UTF-8 strings"
  321: .\"
  322: in the main
  323: .\" HREF
  324: \fBpcreapi\fP
  325: .\"
  326: page. The UTF-16 errors are:
  327: .sp
  328:   PCRE_UTF16_ERR1  Missing low surrogate at end of string
  329:   PCRE_UTF16_ERR2  Invalid low surrogate follows high surrogate
  330:   PCRE_UTF16_ERR3  Isolated low surrogate
  331:   PCRE_UTF16_ERR4  Invalid character 0xfffe
  332: .
  333: .
  334: .SH "ERROR TEXTS"
  335: .rs
  336: .sp
  337: If there is an error while compiling a pattern, the error text that is passed
  338: back by \fBpcre16_compile()\fP or \fBpcre16_compile2()\fP is still an 8-bit
  339: character string, zero-terminated.
  340: .
  341: .
  342: .SH "CALLOUTS"
  343: .rs
  344: .sp
  345: The \fIsubject\fP and \fImark\fP fields in the callout block that is passed to
  346: a callout function point to 16-bit vectors.
  347: .
  348: .
  349: .SH "TESTING"
  350: .rs
  351: .sp
  352: The \fBpcretest\fP program continues to operate with 8-bit input and output
  353: files, but it can be used for testing the 16-bit library. If it is run with the
  354: command line option \fB-16\fP, patterns and subject strings are converted from
  355: 8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions
  356: are used instead of the 8-bit ones. Returned 16-bit strings are converted to
  357: 8-bit for output. If the 8-bit library was not compiled, \fBpcretest\fP
  358: defaults to 16-bit and the \fB-16\fP option is ignored.
  359: .P
  360: When PCRE is being built, the \fBRunTest\fP script that is called by "make
  361: check" uses the \fBpcretest\fP \fB-C\fP option to discover which of the 8-bit
  362: and 16-bit libraries has been built, and runs the tests appropriately.
  363: .
  364: .
  365: .SH "NOT SUPPORTED IN 16-BIT MODE"
  366: .rs
  367: .sp
  368: Not all the features of the 8-bit library are available with the 16-bit
  369: library. The C++ and POSIX wrapper functions support only the 8-bit library,
  370: and the \fBpcregrep\fP program is at present 8-bit only.
  371: .
  372: .
  373: .SH AUTHOR
  374: .rs
  375: .sp
  376: .nf
  377: Philip Hazel
  378: University Computing Service
  379: Cambridge CB2 3QH, England.
  380: .fi
  381: .
  382: .
  383: .SH REVISION
  384: .rs
  385: .sp
  386: .nf
  387: Last updated: 14 April 2012
  388: Copyright (c) 1997-2012 University of Cambridge.
  389: .fi