posix/regex.h

   1 /* Definitions for data structures and routines for the regular
   2    expression library.
   3    Copyright (C) 1985,1989-93,1995-98,2000,2001,2002
   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 /* Allow the use in C++ code.  */
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 /* POSIX says that <sys/types.h> must be included (by the caller) before
  31    <regex.h>.  */
  32
  33 #if !defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE && defined VMS
  34 /* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
  35    should be there.  */
  36 # include <stddef.h>
  37 #endif
  38
  39 /* The following two types have to be signed and unsigned integer type
  40    wide enough to hold a value of a pointer.  For most ANSI compilers
  41    ptrdiff_t and size_t should be likely OK.  Still size of these two
  42    types is 2 for Microsoft C.  Ugh... */
  43 typedef long int s_reg_t;
  44 typedef unsigned long int active_reg_t;
  45
  46 /* The following bits are used to determine the regexp syntax we
  47    recognize.  The set/not-set meanings are chosen so that Emacs syntax
  48    remains the value 0.  The bits are given in alphabetical order, and
  49    the definitions shifted by one from the previous bit; thus, when we
  50    add or remove a bit, only one other definition need change.  */
  51 typedef unsigned long int reg_syntax_t;
  52
  53 /* If this bit is not set, then \ inside a bracket expression is literal.
  54    If set, then such a \ quotes the following character.  */
  55 #define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
  56
  57 /* If this bit is not set, then + and ? are operators, and \+ and \? are
  58      literals.
  59    If set, then \+ and \? are operators and + and ? are literals.  */
  60 #define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
  61
  62 /* If this bit is set, then character classes are supported.  They are:
  63      [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
  64      [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
  65    If not set, then character classes are not supported.  */
  66 #define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
  67
  68 /* If this bit is set, then ^ and $ are always anchors (outside bracket
  69      expressions, of course).
  70    If this bit is not set, then it depends:
  71         ^  is an anchor if it is at the beginning of a regular
  72            expression or after an open-group or an alternation operator;
  73         $  is an anchor if it is at the end of a regular expression, or
  74            before a close-group or an alternation operator.
  75
  76    This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
  77    POSIX draft 11.2 says that * etc. in leading positions is undefined.
  78    We already implemented a previous draft which made those constructs
  79    invalid, though, so we haven't changed the code back.  */
  80 #define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
  81
  82 /* If this bit is set, then special characters are always special
  83      regardless of where they are in the pattern.
  84    If this bit is not set, then special characters are special only in
  85      some contexts; otherwise they are ordinary.  Specifically,
  86      * + ? and intervals are only special when not after the beginning,
  87      open-group, or alternation operator.  */
  88 #define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
  89
  90 /* If this bit is set, then *, +, ?, and { cannot be first in an re or
  91      immediately after an alternation or begin-group operator.  */
  92 #define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
  93
  94 /* If this bit is set, then . matches newline.
  95    If not set, then it doesn't.  */
  96 #define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
  97
  98 /* If this bit is set, then . doesn't match NUL.
  99    If not set, then it does.  */
 100 #define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
 101
 102 /* If this bit is set, nonmatching lists [^...] do not match newline.
 103    If not set, they do.  */
 104 #define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
 105
 106 /* If this bit is set, either \{...\} or {...} defines an
 107      interval, depending on RE_NO_BK_BRACES.
 108    If not set, \{, \}, {, and } are literals.  */
 109 #define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
 110
 111 /* If this bit is set, +, ? and | aren't recognized as operators.
 112    If not set, they are.  */
 113 #define RE_LIMITED_OPS (RE_INTERVALS << 1)
 114
 115 /* If this bit is set, newline is an alternation operator.
 116    If not set, newline is literal.  */
 117 #define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
 118
 119 /* If this bit is set, then `{...}' defines an interval, and \{ and \}
 120      are literals.
 121   If not set, then `\{...\}' defines an interval.  */
 122 #define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
 123
 124 /* If this bit is set, (...) defines a group, and \( and \) are literals.
 125    If not set, \(...\) defines a group, and ( and ) are literals.  */
 126 #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
 127
 128 /* If this bit is set, then \<digit> matches <digit>.
 129    If not set, then \<digit> is a back-reference.  */
 130 #define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
 131
 132 /* If this bit is set, then | is an alternation operator, and \| is literal.
 133    If not set, then \| is an alternation operator, and | is literal.  */
 134 #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
 135
 136 /* If this bit is set, then an ending range point collating higher
 137      than the starting range point, as in [z-a], is invalid.
 138    If not set, then when ending range point collates higher than the
 139      starting range point, the range is ignored.  */
 140 #define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
 141
 142 /* If this bit is set, then an unmatched ) is ordinary.
 143    If not set, then an unmatched ) is invalid.  */
 144 #define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
 145
 146 /* If this bit is set, succeed as soon as we match the whole pattern,
 147    without further backtracking.  */
 148 #define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
 149
 150 /* If this bit is set, do not process the GNU regex operators.
 151    If not set, then the GNU regex operators are recognized. */
 152 #define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
 153
 154 /* If this bit is set, turn on internal regex debugging.
 155    If not set, and debugging was on, turn it off.
 156    This only works if regex.c is compiled -DDEBUG.
 157    We define this bit always, so that all that's needed to turn on
 158    debugging is to recompile regex.c; the calling code can always have
 159    this bit set, and it won't affect anything in the normal case. */
 160 #define RE_DEBUG (RE_NO_GNU_OPS << 1)
 161
 162 /* If this bit is set, a syntactically invalid interval is treated as
 163    a string of ordinary characters.  For example, the ERE 'a{1' is
 164    treated as 'a\{1'.  */
 165 #define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
 166
 167 /* If this bit is set, then ignore case when matching.
 168    If not set, then case is significant.  */
 169 #define RE_ICASE (RE_INVALID_INTERVAL_ORD << 1)
 170
 171 /* This global variable defines the particular regexp syntax to use (for
 172    some interfaces).  When a regexp is compiled, the syntax used is
 173    stored in the pattern buffer, so changing this does not affect
 174    already-compiled regexps.  */
 175 extern reg_syntax_t re_syntax_options;
 176 \f
 177 /* Define combinations of the above bits for the standard possibilities.
 178    (The [[[ comments delimit what gets put into the Texinfo file, so
 179    don't delete them!)  */
 180 /* [[[begin syntaxes]]] */
 181 #define RE_SYNTAX_EMACS 0
 182
 183 #define RE_SYNTAX_AWK                                                   \
 184   (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                     \
 185    | RE_NO_BK_PARENS              | RE_NO_BK_REFS                       \
 186    | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                  \
 187    | RE_DOT_NEWLINE               | RE_CONTEXT_INDEP_ANCHORS            \
 188    | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
 189
 190 #define RE_SYNTAX_GNU_AWK                                               \
 191   ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG) \
 192    & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS            \
 193        | RE_CONTEXT_INVALID_OPS ))
 194
 195 #define RE_SYNTAX_POSIX_AWK                                             \
 196   (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS              \
 197    | RE_INTERVALS           | RE_NO_GNU_OPS)
 198
 199 #define RE_SYNTAX_GREP                                                  \
 200   (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
 201    | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
 202    | RE_NEWLINE_ALT)
 203
 204 #define RE_SYNTAX_EGREP                                                 \
 205   (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
 206    | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
 207    | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
 208    | RE_NO_BK_VBAR)
 209
 210 #define RE_SYNTAX_POSIX_EGREP                                           \
 211   (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES                     \
 212    | RE_INVALID_INTERVAL_ORD)
 213
 214 /* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
 215 #define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
 216
 217 #define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
 218
 219 /* Syntax bits common to both basic and extended POSIX regex syntax.  */
 220 #define _RE_SYNTAX_POSIX_COMMON                                         \
 221   (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
 222    | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
 223
 224 #define RE_SYNTAX_POSIX_BASIC                                           \
 225   (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
 226
 227 /* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
 228    RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
 229    isn't minimal, since other operators, such as \`, aren't disabled.  */
 230 #define RE_SYNTAX_POSIX_MINIMAL_BASIC                                   \
 231   (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
 232
 233 #define RE_SYNTAX_POSIX_EXTENDED                                        \
 234   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 235    | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                           \
 236    | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                             \
 237    | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
 238
 239 /* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
 240    removed and RE_NO_BK_REFS is added.  */
 241 #define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                                \
 242   (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
 243    | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
 244    | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
 245    | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)
 246 /* [[[end syntaxes]]] */
 247 \f
 248 /* Maximum number of duplicates an interval can allow.  Some systems
 249    (erroneously) define this in other header files, but we want our
 250    value, so remove any previous define.  */
 251 #ifdef RE_DUP_MAX
 252 # undef RE_DUP_MAX
 253 #endif
 254 /* If sizeof(int) == 2, then ((1 << 15) - 1) overflows.  */
 255 #define RE_DUP_MAX (0x7fff)
 256
 257
 258 /* POSIX `cflags' bits (i.e., information for `regcomp').  */
 259
 260 /* If this bit is set, then use extended regular expression syntax.
 261    If not set, then use basic regular expression syntax.  */
 262 #define REG_EXTENDED 1
 263
 264 /* If this bit is set, then ignore case when matching.
 265    If not set, then case is significant.  */
 266 #define REG_ICASE (REG_EXTENDED << 1)
 267
 268 /* If this bit is set, then anchors do not match at newline
 269      characters in the string.
 270    If not set, then anchors do match at newlines.  */
 271 #define REG_NEWLINE (REG_ICASE << 1)
 272
 273 /* If this bit is set, then report only success or fail in regexec.
 274    If not set, then returns differ between not matching and errors.  */
 275 #define REG_NOSUB (REG_NEWLINE << 1)
 276
 277
 278 /* POSIX `eflags' bits (i.e., information for regexec).  */
 279
 280 /* If this bit is set, then the beginning-of-line operator doesn't match
 281      the beginning of the string (presumably because it's not the
 282      beginning of a line).
 283    If not set, then the beginning-of-line operator does match the
 284      beginning of the string.  */
 285 #define REG_NOTBOL 1
 286
 287 /* Like REG_NOTBOL, except for the end-of-line.  */
 288 #define REG_NOTEOL (1 << 1)
 289
 290
 291 /* If any error codes are removed, changed, or added, update the
 292    `re_error_msg' table in regex.c.  */
 293 typedef enum
 294 {
 295 #ifdef _XOPEN_SOURCE
 296   REG_ENOSYS = -1,      /* This will never happen for this implementation.  */
 297 #endif
 298
 299   REG_NOERROR = 0,      /* Success.  */
 300   REG_NOMATCH,          /* Didn't find a match (for regexec).  */
 301
 302   /* POSIX regcomp return error codes.  (In the order listed in the
 303      standard.)  */
 304   REG_BADPAT,           /* Invalid pattern.  */
 305   REG_ECOLLATE,         /* Not implemented.  */
 306   REG_ECTYPE,           /* Invalid character class name.  */
 307   REG_EESCAPE,          /* Trailing backslash.  */
 308   REG_ESUBREG,          /* Invalid back reference.  */
 309   REG_EBRACK,           /* Unmatched left bracket.  */
 310   REG_EPAREN,           /* Parenthesis imbalance.  */
 311   REG_EBRACE,           /* Unmatched \{.  */
 312   REG_BADBR,            /* Invalid contents of \{\}.  */
 313   REG_ERANGE,           /* Invalid range end.  */
 314   REG_ESPACE,           /* Ran out of memory.  */
 315   REG_BADRPT,           /* No preceding re for repetition op.  */
 316
 317   /* Error codes we've added.  */
 318   REG_EEND,             /* Premature end.  */
 319   REG_ESIZE,            /* Compiled pattern bigger than 2^16 bytes.  */
 320   REG_ERPAREN           /* Unmatched ) or \); not returned from regcomp.  */
 321 } reg_errcode_t;
 322 \f
 323 /* This data structure represents a compiled pattern.  Before calling
 324    the pattern compiler, the fields `buffer', `allocated', `fastmap',
 325    `translate', and `no_sub' can be set.  After the pattern has been
 326    compiled, the `re_nsub' field is available.  All other fields are
 327    private to the regex routines.  */
 328
 329 #ifndef RE_TRANSLATE_TYPE
 330 # define RE_TRANSLATE_TYPE char *
 331 #endif
 332
 333 struct re_pattern_buffer
 334 {
 335 /* [[[begin pattern_buffer]]] */
 336         /* Space that holds the compiled pattern.  It is declared as
 337           `unsigned char *' because its elements are
 338            sometimes used as array indexes.  */
 339   unsigned char *buffer;
 340
 341         /* Number of bytes to which `buffer' points.  */
 342   unsigned long int allocated;
 343
 344         /* Number of bytes actually used in `buffer'.  */
 345   unsigned long int used;
 346
 347         /* Syntax setting with which the pattern was compiled.  */
 348   reg_syntax_t syntax;
 349
 350         /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
 351            the fastmap, if there is one, to skip over impossible
 352            starting points for matches.  */
 353   char *fastmap;
 354
 355         /* Either a translate table to apply to all characters before
 356            comparing them, or zero for no translation.  The translation
 357            is applied to a pattern when it is compiled and to a string
 358            when it is matched.  */
 359   RE_TRANSLATE_TYPE translate;
 360
 361         /* Number of subexpressions found by the compiler.  */
 362   size_t re_nsub;
 363
 364         /* Zero if this pattern cannot match the empty string, one else.
 365            Well, in truth it's used only in `re_search_2', to see
 366            whether or not we should use the fastmap, so we don't set
 367            this absolutely perfectly; see `re_compile_fastmap' (the
 368            `duplicate' case).  */
 369   unsigned can_be_null : 1;
 370
 371         /* If REGS_UNALLOCATED, allocate space in the `regs' structure
 372              for `max (RE_NREGS, re_nsub + 1)' groups.
 373            If REGS_REALLOCATE, reallocate space if necessary.
 374            If REGS_FIXED, use what's there.  */
 375 #define REGS_UNALLOCATED 0
 376 #define REGS_REALLOCATE 1
 377 #define REGS_FIXED 2
 378   unsigned regs_allocated : 2;
 379
 380         /* Set to zero when `regex_compile' compiles a pattern; set to one
 381            by `re_compile_fastmap' if it updates the fastmap.  */
 382   unsigned fastmap_accurate : 1;
 383
 384         /* If set, `re_match_2' does not return information about
 385            subexpressions.  */
 386   unsigned no_sub : 1;
 387
 388         /* If set, a beginning-of-line anchor doesn't match at the
 389            beginning of the string.  */
 390   unsigned not_bol : 1;
 391
 392         /* Similarly for an end-of-line anchor.  */
 393   unsigned not_eol : 1;
 394
 395         /* If true, an anchor at a newline matches.  */
 396   unsigned newline_anchor : 1;
 397
 398 /* [[[end pattern_buffer]]] */
 399 };
 400
 401 typedef struct re_pattern_buffer regex_t;
 402 \f
 403 /* Type for byte offsets within the string.  POSIX mandates this.  */
 404 typedef int regoff_t;
 405
 406
 407 /* This is the structure we store register match data in.  See
 408    regex.texinfo for a full description of what registers match.  */
 409 struct re_registers
 410 {
 411   unsigned num_regs;
 412   regoff_t *start;
 413   regoff_t *end;
 414 };
 415
 416
 417 /* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
 418    `re_match_2' returns information about at least this many registers
 419    the first time a `regs' structure is passed.  */
 420 #ifndef RE_NREGS
 421 # define RE_NREGS 30
 422 #endif
 423
 424
 425 /* POSIX specification for registers.  Aside from the different names than
 426    `re_registers', POSIX uses an array of structures, instead of a
 427    structure of arrays.  */
 428 typedef struct
 429 {
 430   regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
 431   regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
 432 } regmatch_t;
 433 \f
 434 /* Declarations for routines.  */
 435
 436 /* To avoid duplicating every routine declaration -- once with a
 437    prototype (if we are ANSI), and once without (if we aren't) -- we
 438    use the following macro to declare argument types.  This
 439    unfortunately clutters up the declarations a bit, but I think it's
 440    worth it.  */
 441
 442 #if __STDC__
 443
 444 # define _RE_ARGS(args) args
 445
 446 #else /* not __STDC__ */
 447
 448 # define _RE_ARGS(args) ()
 449
 450 #endif /* not __STDC__ */
 451
 452 /* Sets the current default syntax to SYNTAX, and return the old syntax.
 453    You can also simply assign to the `re_syntax_options' variable.  */
 454 extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
 455
 456 /* Compile the regular expression PATTERN, with length LENGTH
 457    and syntax given by the global `re_syntax_options', into the buffer
 458    BUFFER.  Return NULL if successful, and an error string if not.  */
 459 extern const char *re_compile_pattern
 460   _RE_ARGS ((const char *pattern, size_t length,
 461              struct re_pattern_buffer *buffer));
 462
 463
 464 /* Compile a fastmap for the compiled pattern in BUFFER; used to
 465    accelerate searches.  Return 0 if successful and -2 if was an
 466    internal error.  */
 467 extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
 468
 469
 470 /* Search in the string STRING (with length LENGTH) for the pattern
 471    compiled into BUFFER.  Start searching at position START, for RANGE
 472    characters.  Return the starting position of the match, -1 for no
 473    match, or -2 for an internal error.  Also return register
 474    information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
 475 extern int re_search
 476   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 477             int length, int start, int range, struct re_registers *regs));
 478
 479
 480 /* Like `re_search', but search in the concatenation of STRING1 and
 481    STRING2.  Also, stop searching at index START + STOP.  */
 482 extern int re_search_2
 483   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 484              int length1, const char *string2, int length2,
 485              int start, int range, struct re_registers *regs, int stop));
 486
 487
 488 /* Like `re_search', but return how many characters in STRING the regexp
 489    in BUFFER matched, starting at position START.  */
 490 extern int re_match
 491   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
 492              int length, int start, struct re_registers *regs));
 493
 494
 495 /* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
 496 extern int re_match_2
 497   _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
 498              int length1, const char *string2, int length2,
 499              int start, struct re_registers *regs, int stop));
 500
 501
 502 /* Set REGS to hold NUM_REGS registers, storing them in STARTS and
 503    ENDS.  Subsequent matches using BUFFER and REGS will use this memory
 504    for recording register information.  STARTS and ENDS must be
 505    allocated with malloc, and must each be at least `NUM_REGS * sizeof
 506    (regoff_t)' bytes long.
 507
 508    If NUM_REGS == 0, then subsequent matches should allocate their own
 509    register data.
 510
 511    Unless this function is called, the first search or match using
 512    PATTERN_BUFFER will allocate its own register data, without
 513    freeing the old data.  */
 514 extern void re_set_registers
 515   _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
 516              unsigned num_regs, regoff_t *starts, regoff_t *ends));
 517
 518 #if defined _REGEX_RE_COMP || defined _LIBC
 519 # ifndef _CRAY
 520 /* 4.2 bsd compatibility.  */
 521 extern char *re_comp _RE_ARGS ((const char *));
 522 extern int re_exec _RE_ARGS ((const char *));
 523 # endif
 524 #endif
 525
 526 /* GCC 2.95 and later have "__restrict"; C99 compilers have
 527    "restrict", and "configure" may have defined "restrict".  */
 528 #ifndef __restrict
 529 # if ! (2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__))
 530 #  if defined restrict || 199901L <= __STDC_VERSION__
 531 #   define __restrict restrict
 532 #  else
 533 #   define __restrict
 534 #  endif
 535 # endif
 536 #endif
 537 /* gcc 3.1 and up support the [restrict] syntax.  */
 538 #ifndef __restrict_arr
 539 # if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
 540 #  define __restrict_arr __restrict
 541 # else
 542 #  define __restrict_arr
 543 # endif
 544 #endif
 545
 546 /* POSIX compatibility.  */
 547 extern int regcomp _RE_ARGS ((regex_t *__restrict __preg,
 548                               const char *__restrict __pattern,
 549                               int __cflags));
 550
 551 extern int regexec _RE_ARGS ((const regex_t *__restrict __preg,
 552                               const char *__restrict __string, size_t __nmatch,
 553                               regmatch_t __pmatch[__restrict_arr],
 554                               int __eflags));
 555
 556 extern size_t regerror _RE_ARGS ((int __errcode, const regex_t *__preg,
 557                                   char *__errbuf, size_t __errbuf_size));
 558
 559 extern void regfree _RE_ARGS ((regex_t *__preg));
 560
 561
 562 #ifdef __cplusplus
 563 }
 564 #endif  /* C++ */
 565
 566 #endif /* regex.h */
 567 \f
 568 /*
 569 Local variables:
 570 make-backup-files: t
 571 version-control: t
 572 trim-versions-without-asking: nil
 573 End:
 574 */