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      1 /* Definitions for data structures and routines for the regular
      2    expression library.
      3    Copyright (C) 1985,1989-93,1995-98,2000,2001,2002,2003,2005,2006,2008
      4    Free Software Foundation, Inc.
      5    This file is part of the GNU C Library.
      6 
      7    The GNU C Library is free software; you can redistribute it and/or
      8    modify it under the terms of the GNU Lesser General Public
      9    License as published by the Free Software Foundation; either
     10    version 2.1 of the License, or (at your option) any later version.
     11 
     12    The GNU C Library is distributed in the hope that it will be useful,
     13    but WITHOUT ANY WARRANTY; without even the implied warranty of
     14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     15    Lesser General Public License for more details.
     16 
     17    You should have received a copy of the GNU Lesser General Public
     18    License along with the GNU C Library; if not, write to the Free
     19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     20    02111-1307 USA.  */
     21 
     22 #ifndef _REGEX_H
     23 #define _REGEX_H 1
     24 
     25 #include <sys/types.h>
     26 #include <gnu/option-groups.h>
     27 
     28 /* Allow the use in C++ code.  */
     29 #ifdef __cplusplus
     30 extern "C" {
     31 #endif
     32 
     33 /* The following two types have to be signed and unsigned integer type
     34    wide enough to hold a value of a pointer.  For most ANSI compilers
     35    ptrdiff_t and size_t should be likely OK.  Still size of these two
     36    types is 2 for Microsoft C.  Ugh... */
     37 typedef long int s_reg_t;
     38 typedef unsigned long int active_reg_t;
     39 
     40 /* The following bits are used to determine the regexp syntax we
     41    recognize.  The set/not-set meanings are chosen so that Emacs syntax
     42    remains the value 0.  The bits are given in alphabetical order, and
     43    the definitions shifted by one from the previous bit; thus, when we
     44    add or remove a bit, only one other definition need change.  */
     45 typedef unsigned long int reg_syntax_t;
     46 
     47 #ifdef __USE_GNU
     48 /* If this bit is not set, then \ inside a bracket expression is literal.
     49    If set, then such a \ quotes the following character.  */
     50 # define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
     51 
     52 /* If this bit is not set, then + and ? are operators, and \+ and \? are
     53      literals.
     54    If set, then \+ and \? are operators and + and ? are literals.  */
     55 # define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
     56 
     57 /* If this bit is set, then character classes are supported.  They are:
     58      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
     59      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
     60    If not set, then character classes are not supported.  */
     61 # define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
     62 
     63 /* If this bit is set, then ^ and $ are always anchors (outside bracket
     64      expressions, of course).
     65    If this bit is not set, then it depends:
     66         ^  is an anchor if it is at the beginning of a regular
     67            expression or after an open-group or an alternation operator;
     68         $  is an anchor if it is at the end of a regular expression, or
     69            before a close-group or an alternation operator.
     70 
     71    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
     72    POSIX draft 11.2 says that * etc. in leading positions is undefined.
     73    We already implemented a previous draft which made those constructs
     74    invalid, though, so we haven't changed the code back.  */
     75 # define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
     76 
     77 /* If this bit is set, then special characters are always special
     78      regardless of where they are in the pattern.
     79    If this bit is not set, then special characters are special only in
     80      some contexts; otherwise they are ordinary.  Specifically,
     81      * + ? and intervals are only special when not after the beginning,
     82      open-group, or alternation operator.  */
     83 # define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
     84 
     85 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
     86      immediately after an alternation or begin-group operator.  */
     87 # define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
     88 
     89 /* If this bit is set, then . matches newline.
     90    If not set, then it doesn't.  */
     91 # define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
     92 
     93 /* If this bit is set, then . doesn't match NUL.
     94    If not set, then it does.  */
     95 # define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
     96 
     97 /* If this bit is set, nonmatching lists [^...] do not match newline.
     98    If not set, they do.  */
     99 # define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
    100 
    101 /* If this bit is set, either \{...\} or {...} defines an
    102      interval, depending on RE_NO_BK_BRACES.
    103    If not set, \{, \}, {, and } are literals.  */
    104 # define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
    105 
    106 /* If this bit is set, +, ? and | aren't recognized as operators.
    107    If not set, they are.  */
    108 # define RE_LIMITED_OPS (RE_INTERVALS << 1)
    109 
    110 /* If this bit is set, newline is an alternation operator.
    111    If not set, newline is literal.  */
    112 # define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
    113 
    114 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
    115      are literals.
    116   If not set, then `\{...\}' defines an interval.  */
    117 # define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
    118 
    119 /* If this bit is set, (...) defines a group, and \( and \) are literals.
    120    If not set, \(...\) defines a group, and ( and ) are literals.  */
    121 # define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
    122 
    123 /* If this bit is set, then \<digit> matches <digit>.
    124    If not set, then \<digit> is a back-reference.  */
    125 # define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
    126 
    127 /* If this bit is set, then | is an alternation operator, and \| is literal.
    128    If not set, then \| is an alternation operator, and | is literal.  */
    129 # define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
    130 
    131 /* If this bit is set, then an ending range point collating higher
    132      than the starting range point, as in [z-a], is invalid.
    133    If not set, then when ending range point collates higher than the
    134      starting range point, the range is ignored.  */
    135 # define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
    136 
    137 /* If this bit is set, then an unmatched ) is ordinary.
    138    If not set, then an unmatched ) is invalid.  */
    139 # define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
    140 
    141 /* If this bit is set, succeed as soon as we match the whole pattern,
    142    without further backtracking.  */
    143 # define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
    144 
    145 /* If this bit is set, do not process the GNU regex operators.
    146    If not set, then the GNU regex operators are recognized. */
    147 # define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
    148 
    149 /* If this bit is set, turn on internal regex debugging.
    150    If not set, and debugging was on, turn it off.
    151    This only works if regex.c is compiled -DDEBUG.
    152    We define this bit always, so that all that's needed to turn on
    153    debugging is to recompile regex.c; the calling code can always have
    154    this bit set, and it won't affect anything in the normal case. */
    155 # define RE_DEBUG (RE_NO_GNU_OPS << 1)
    156 
    157 /* If this bit is set, a syntactically invalid interval is treated as
    158    a string of ordinary characters.  For example, the ERE 'a{1' is
    159    treated as 'a\{1'.  */
    160 # define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
    161 
    162 /* EGLIBC: Old regex implementation does not support these.  */
    163 # ifdef __OPTION_POSIX_REGEXP_GLIBC
    164 /* If this bit is set, then ignore case when matching.
    165    If not set, then case is significant.  */
    166 # define RE_ICASE (RE_INVALID_INTERVAL_ORD << 1)
    167 
    168 /* This bit is used internally like RE_CONTEXT_INDEP_ANCHORS but only
    169    for ^, because it is difficult to scan the regex backwards to find
    170    whether ^ should be special.  */
    171 # define RE_CARET_ANCHORS_HERE (RE_ICASE << 1)
    172 
    173 /* If this bit is set, then \{ cannot be first in an bre or
    174    immediately after an alternation or begin-group operator.  */
    175 # define RE_CONTEXT_INVALID_DUP (RE_CARET_ANCHORS_HERE << 1)
    176 
    177 /* If this bit is set, then no_sub will be set to 1 during
    178    re_compile_pattern.  */
    179 # define RE_NO_SUB (RE_CONTEXT_INVALID_DUP << 1)
    180 # endif /* __OPTION_POSIX_REGEXP_GLIBC */
    181 #endif
    182 
    183 /* This global variable defines the particular regexp syntax to use (for
    184    some interfaces).  When a regexp is compiled, the syntax used is
    185    stored in the pattern buffer, so changing this does not affect
    186    already-compiled regexps.  */
    187 extern reg_syntax_t re_syntax_options;
    188 
    189 #ifdef __USE_GNU
    191 /* Define combinations of the above bits for the standard possibilities.
    192    (The [[[ comments delimit what gets put into the Texinfo file, so
    193    don't delete them!)  */
    194 /* [[[begin syntaxes]]] */
    195 #define RE_SYNTAX_EMACS 0
    196 
    197 #define RE_SYNTAX_AWK							\
    198   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL			\
    199    | RE_NO_BK_PARENS              | RE_NO_BK_REFS			\
    200    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES			\
    201    | RE_DOT_NEWLINE		  | RE_CONTEXT_INDEP_ANCHORS		\
    202    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
    203 
    204 #define RE_SYNTAX_GNU_AWK						\
    205   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG)	\
    206    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS		\
    207        | RE_CONTEXT_INVALID_OPS ))
    208 
    209 #define RE_SYNTAX_POSIX_AWK						\
    210   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS		\
    211    | RE_INTERVALS	    | RE_NO_GNU_OPS)
    212 
    213 #define RE_SYNTAX_GREP							\
    214   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES				\
    215    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS				\
    216    | RE_NEWLINE_ALT)
    217 
    218 #define RE_SYNTAX_EGREP							\
    219   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS			\
    220    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE			\
    221    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS				\
    222    | RE_NO_BK_VBAR)
    223 
    224 #define RE_SYNTAX_POSIX_EGREP						\
    225   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES			\
    226    | RE_INVALID_INTERVAL_ORD)
    227 
    228 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
    229 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
    230 
    231 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
    232 
    233 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
    234 #define _RE_SYNTAX_POSIX_COMMON						\
    235   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL		\
    236    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
    237 
    238 #ifdef __OPTION_POSIX_REGEXP_GLIBC
    239 #define RE_SYNTAX_POSIX_BASIC						\
    240   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM | RE_CONTEXT_INVALID_DUP)
    241 #else
    242 #define RE_SYNTAX_POSIX_BASIC						\
    243   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
    244 #endif
    245 
    246 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
    247    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
    248    isn't minimal, since other operators, such as \`, aren't disabled.  */
    249 #define RE_SYNTAX_POSIX_MINIMAL_BASIC					\
    250   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
    251 
    252 #define RE_SYNTAX_POSIX_EXTENDED					\
    253   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
    254    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES				\
    255    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR				\
    256    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
    257 
    258 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
    259    removed and RE_NO_BK_REFS is added.  */
    260 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED				\
    261   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
    262    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES				\
    263    | RE_NO_BK_PARENS        | RE_NO_BK_REFS				\
    264    | RE_NO_BK_VBAR	    | RE_UNMATCHED_RIGHT_PAREN_ORD)
    265 /* [[[end syntaxes]]] */
    266 
    267 /* Maximum number of duplicates an interval can allow.  Some systems
    269    (erroneously) define this in other header files, but we want our
    270    value, so remove any previous define.  */
    271 # ifdef RE_DUP_MAX
    272 #  undef RE_DUP_MAX
    273 # endif
    274 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
    275 # define RE_DUP_MAX (0x7fff)
    276 #endif
    277 
    278 
    279 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
    280 
    281 /* If this bit is set, then use extended regular expression syntax.
    282    If not set, then use basic regular expression syntax.  */
    283 #define REG_EXTENDED 1
    284 
    285 /* If this bit is set, then ignore case when matching.
    286    If not set, then case is significant.  */
    287 #define REG_ICASE (REG_EXTENDED << 1)
    288 
    289 /* If this bit is set, then anchors do not match at newline
    290      characters in the string.
    291    If not set, then anchors do match at newlines.  */
    292 #define REG_NEWLINE (REG_ICASE << 1)
    293 
    294 /* If this bit is set, then report only success or fail in regexec.
    295    If not set, then returns differ between not matching and errors.  */
    296 #define REG_NOSUB (REG_NEWLINE << 1)
    297 
    298 
    299 /* POSIX `eflags' bits (i.e., information for regexec).  */
    300 
    301 /* If this bit is set, then the beginning-of-line operator doesn't match
    302      the beginning of the string (presumably because it's not the
    303      beginning of a line).
    304    If not set, then the beginning-of-line operator does match the
    305      beginning of the string.  */
    306 #define REG_NOTBOL 1
    307 
    308 /* Like REG_NOTBOL, except for the end-of-line.  */
    309 #define REG_NOTEOL (1 << 1)
    310 
    311 #ifdef __OPTION_POSIX_REGEXP_GLIBC
    312 /* Use PMATCH[0] to delimit the start and end of the search in the
    313    buffer.  */
    314 #define REG_STARTEND (1 << 2)
    315 #endif
    316 
    317 
    318 /* If any error codes are removed, changed, or added, update the
    319    `re_error_msg' table in regex.c.  */
    320 typedef enum
    321 {
    322 #if defined _XOPEN_SOURCE || defined __USE_XOPEN2K
    323   REG_ENOSYS = -1,	/* This will never happen for this implementation.  */
    324 #endif
    325 
    326   REG_NOERROR = 0,	/* Success.  */
    327   REG_NOMATCH,		/* Didn't find a match (for regexec).  */
    328 
    329   /* POSIX regcomp return error codes.  (In the order listed in the
    330      standard.)  */
    331   REG_BADPAT,		/* Invalid pattern.  */
    332   REG_ECOLLATE,		/* Inalid collating element.  */
    333   REG_ECTYPE,		/* Invalid character class name.  */
    334   REG_EESCAPE,		/* Trailing backslash.  */
    335   REG_ESUBREG,		/* Invalid back reference.  */
    336   REG_EBRACK,		/* Unmatched left bracket.  */
    337   REG_EPAREN,		/* Parenthesis imbalance.  */
    338   REG_EBRACE,		/* Unmatched \{.  */
    339   REG_BADBR,		/* Invalid contents of \{\}.  */
    340   REG_ERANGE,		/* Invalid range end.  */
    341   REG_ESPACE,		/* Ran out of memory.  */
    342   REG_BADRPT,		/* No preceding re for repetition op.  */
    343 
    344   /* Error codes we've added.  */
    345   REG_EEND,		/* Premature end.  */
    346   REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
    347   REG_ERPAREN		/* Unmatched ) or \); not returned from regcomp.  */
    348 } reg_errcode_t;
    349 
    350 /* This data structure represents a compiled pattern.  Before calling
    352    the pattern compiler, the fields `buffer', `allocated', `fastmap',
    353    `translate', and `no_sub' can be set.  After the pattern has been
    354    compiled, the `re_nsub' field is available.  All other fields are
    355    private to the regex routines.  */
    356 
    357 #ifndef RE_TRANSLATE_TYPE
    358 # define __RE_TRANSLATE_TYPE unsigned char *
    359 # ifdef __USE_GNU
    360 #  define RE_TRANSLATE_TYPE __RE_TRANSLATE_TYPE
    361 # endif
    362 #endif
    363 
    364 #ifdef __USE_GNU
    365 # define __REPB_PREFIX(name) name
    366 #else
    367 # define __REPB_PREFIX(name) __##name
    368 #endif
    369 
    370 struct re_pattern_buffer
    371 {
    372   /* Space that holds the compiled pattern.  It is declared as
    373      `unsigned char *' because its elements are sometimes used as
    374      array indexes.  */
    375   unsigned char *__REPB_PREFIX(buffer);
    376 
    377   /* Number of bytes to which `buffer' points.  */
    378   unsigned long int __REPB_PREFIX(allocated);
    379 
    380   /* Number of bytes actually used in `buffer'.  */
    381   unsigned long int __REPB_PREFIX(used);
    382 
    383   /* Syntax setting with which the pattern was compiled.  */
    384   reg_syntax_t __REPB_PREFIX(syntax);
    385 
    386   /* Pointer to a fastmap, if any, otherwise zero.  re_search uses the
    387      fastmap, if there is one, to skip over impossible starting points
    388      for matches.  */
    389   char *__REPB_PREFIX(fastmap);
    390 
    391   /* Either a translate table to apply to all characters before
    392      comparing them, or zero for no translation.  The translation is
    393      applied to a pattern when it is compiled and to a string when it
    394      is matched.  */
    395   __RE_TRANSLATE_TYPE __REPB_PREFIX(translate);
    396 
    397   /* Number of subexpressions found by the compiler.  */
    398   size_t re_nsub;
    399 
    400   /* Zero if this pattern cannot match the empty string, one else.
    401      Well, in truth it's used only in `re_search_2', to see whether or
    402      not we should use the fastmap, so we don't set this absolutely
    403      perfectly; see `re_compile_fastmap' (the `duplicate' case).  */
    404   unsigned __REPB_PREFIX(can_be_null) : 1;
    405 
    406   /* If REGS_UNALLOCATED, allocate space in the `regs' structure
    407      for `max (RE_NREGS, re_nsub + 1)' groups.
    408      If REGS_REALLOCATE, reallocate space if necessary.
    409      If REGS_FIXED, use what's there.  */
    410 #ifdef __USE_GNU
    411 # define REGS_UNALLOCATED 0
    412 # define REGS_REALLOCATE 1
    413 # define REGS_FIXED 2
    414 #endif
    415   unsigned __REPB_PREFIX(regs_allocated) : 2;
    416 
    417   /* Set to zero when `regex_compile' compiles a pattern; set to one
    418      by `re_compile_fastmap' if it updates the fastmap.  */
    419   unsigned __REPB_PREFIX(fastmap_accurate) : 1;
    420 
    421   /* If set, `re_match_2' does not return information about
    422      subexpressions.  */
    423   unsigned __REPB_PREFIX(no_sub) : 1;
    424 
    425   /* If set, a beginning-of-line anchor doesn't match at the beginning
    426      of the string.  */
    427   unsigned __REPB_PREFIX(not_bol) : 1;
    428 
    429   /* Similarly for an end-of-line anchor.  */
    430   unsigned __REPB_PREFIX(not_eol) : 1;
    431 
    432   /* If true, an anchor at a newline matches.  */
    433   unsigned __REPB_PREFIX(newline_anchor) : 1;
    434 };
    435 
    436 typedef struct re_pattern_buffer regex_t;
    437 
    438 /* Type for byte offsets within the string.  POSIX mandates this.  */
    440 typedef int regoff_t;
    441 
    442 
    443 #ifdef __USE_GNU
    444 /* This is the structure we store register match data in.  See
    445    regex.texinfo for a full description of what registers match.  */
    446 struct re_registers
    447 {
    448   unsigned num_regs;
    449   regoff_t *start;
    450   regoff_t *end;
    451 };
    452 
    453 
    454 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
    455    `re_match_2' returns information about at least this many registers
    456    the first time a `regs' structure is passed.  */
    457 # ifndef RE_NREGS
    458 #  define RE_NREGS 30
    459 # endif
    460 #endif
    461 
    462 
    463 /* POSIX specification for registers.  Aside from the different names than
    464    `re_registers', POSIX uses an array of structures, instead of a
    465    structure of arrays.  */
    466 typedef struct
    467 {
    468   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
    469   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
    470 } regmatch_t;
    471 
    472 /* Declarations for routines.  */
    474 
    475 #ifdef __USE_GNU
    476 /* Sets the current default syntax to SYNTAX, and return the old syntax.
    477    You can also simply assign to the `re_syntax_options' variable.  */
    478 extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax);
    479 
    480 /* Compile the regular expression PATTERN, with length LENGTH
    481    and syntax given by the global `re_syntax_options', into the buffer
    482    BUFFER.  Return NULL if successful, and an error string if not.  */
    483 extern const char *re_compile_pattern (const char *__pattern, size_t __length,
    484 				       struct re_pattern_buffer *__buffer);
    485 
    486 
    487 /* Compile a fastmap for the compiled pattern in BUFFER; used to
    488    accelerate searches.  Return 0 if successful and -2 if was an
    489    internal error.  */
    490 extern int re_compile_fastmap (struct re_pattern_buffer *__buffer);
    491 
    492 
    493 /* Search in the string STRING (with length LENGTH) for the pattern
    494    compiled into BUFFER.  Start searching at position START, for RANGE
    495    characters.  Return the starting position of the match, -1 for no
    496    match, or -2 for an internal error.  Also return register
    497    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
    498 extern int re_search (struct re_pattern_buffer *__buffer, const char *__string,
    499 		      int __length, int __start, int __range,
    500 		      struct re_registers *__regs);
    501 
    502 
    503 /* Like `re_search', but search in the concatenation of STRING1 and
    504    STRING2.  Also, stop searching at index START + STOP.  */
    505 extern int re_search_2 (struct re_pattern_buffer *__buffer,
    506 			const char *__string1, int __length1,
    507 			const char *__string2, int __length2, int __start,
    508 			int __range, struct re_registers *__regs, int __stop);
    509 
    510 
    511 /* Like `re_search', but return how many characters in STRING the regexp
    512    in BUFFER matched, starting at position START.  */
    513 extern int re_match (struct re_pattern_buffer *__buffer, const char *__string,
    514 		     int __length, int __start, struct re_registers *__regs);
    515 
    516 
    517 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
    518 extern int re_match_2 (struct re_pattern_buffer *__buffer,
    519 		       const char *__string1, int __length1,
    520 		       const char *__string2, int __length2, int __start,
    521 		       struct re_registers *__regs, int __stop);
    522 
    523 
    524 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
    525    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
    526    for recording register information.  STARTS and ENDS must be
    527    allocated with malloc, and must each be at least `NUM_REGS * sizeof
    528    (regoff_t)' bytes long.
    529 
    530    If NUM_REGS == 0, then subsequent matches should allocate their own
    531    register data.
    532 
    533    Unless this function is called, the first search or match using
    534    PATTERN_BUFFER will allocate its own register data, without
    535    freeing the old data.  */
    536 extern void re_set_registers (struct re_pattern_buffer *__buffer,
    537 			      struct re_registers *__regs,
    538 			      unsigned int __num_regs,
    539 			      regoff_t *__starts, regoff_t *__ends);
    540 #endif	/* Use GNU */
    541 
    542 #if defined _REGEX_RE_COMP || (defined _LIBC && defined __USE_BSD)
    543 # ifndef _CRAY
    544 /* 4.2 bsd compatibility.  */
    545 extern char *re_comp (const char *);
    546 extern int re_exec (const char *);
    547 # endif
    548 #endif
    549 
    550 /* GCC 2.95 and later have "__restrict"; C99 compilers have
    551    "restrict", and "configure" may have defined "restrict".  */
    552 #ifndef __restrict
    553 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
    554 #  if defined restrict || 199901L <= __STDC_VERSION__
    555 #   define __restrict restrict
    556 #  else
    557 #   define __restrict
    558 #  endif
    559 # endif
    560 #endif
    561 /* gcc 3.1 and up support the [restrict] syntax.  */
    562 #ifndef __restrict_arr
    563 # if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)) \
    564      && !defined __GNUG__
    565 #  define __restrict_arr __restrict
    566 # else
    567 #  define __restrict_arr
    568 # endif
    569 #endif
    570 
    571 /* POSIX compatibility.  */
    572 extern int regcomp (regex_t *__restrict __preg,
    573 		    const char *__restrict __pattern,
    574 		    int __cflags);
    575 
    576 extern int regexec (const regex_t *__restrict __preg,
    577 		    const char *__restrict __string, size_t __nmatch,
    578 		    regmatch_t __pmatch[__restrict_arr],
    579 		    int __eflags);
    580 
    581 extern size_t regerror (int __errcode, const regex_t *__restrict __preg,
    582 			char *__restrict __errbuf, size_t __errbuf_size);
    583 
    584 extern void regfree (regex_t *__preg);
    585 
    586 
    587 #ifdef __cplusplus
    588 }
    589 #endif	/* C++ */
    590 
    591 #endif /* regex.h */
    592