[comp.sources.bugs] Better pattern matching for `rh'

cudcv@warwick.ac.uk (Rob McMahon) (05/04/89)

The author of `rh' himself admitted that the choice of "*name" or "name*" in
rh's pattern matching was inadequate.  It seems more natural to have the
shell-style `?', `*', and `[' metacharacters here than full regular
expressions.  Maybe there should be an alternative "/re/" since only the last
component is checked, so that there can be no slashes in the pattern.

Since the pattern matching code from BSD's ftp is publicly distributable, I
glued it in, after hopefully making it 8-bit clean.  Here are my diffs, this
allows patterns such as "a?[b-y]\*\"z*".  This will need `-Drindex=strrchr'
for systems that use `strrchr' instead of `rindex'.  Note that it doesn't
ignore files that start with `.', I'm not sure if this is a feature.

RCS file: rh.man,v
retrieving revision 1.1
diff -c -r1.1 rh.man
*** /tmp/,RCSt1a01638	Wed May  3 18:30:00 1989
--- rh.man	Wed May  3 17:13:28 1989
***************
*** 176,187 ****
  This operater evaluates to the integer uid of
  .I username.
  .PP
! .IP """*.c"""
  This operator evaluates to true if the current filename matches
! "expression". The only form of 
  .I expression
! supported is, "filename", "*filename", "filename*", "*".
! When doing comparisons, only the base name is examined, not
  pathnames.
  .PP
  .IP [yyyy/mm/dd]
--- 176,187 ----
  This operater evaluates to the integer uid of
  .I username.
  .PP
! .IP """\fIexpression\fR"""
  This operator evaluates to true if the current filename matches
! "expression".
  .I expression
! may contain the normal `*', `?', and `[' shell metacharacters, which can be
! quoted with `\e'.  When doing comparisons, only the base name is examined, not
  pathnames.
  .PP
  .IP [yyyy/mm/dd]
===================================================================
RCS file: rhcmds.c,v
retrieving revision 1.1
diff -c -r1.1 rhcmds.c
*** /tmp/,RCSt1a01638	Wed May  3 18:30:04 1989
--- rhcmds.c	Wed May  3 18:29:13 1989
***************
*** 10,15 ****
--- 10,33 ----
   *
   * ---------------------------------------------------------------------- */
  
+ /* Gmatch is taken from the Berkeley ftp code, and is protected thus: */
+ /*
+  * Copyright (c) 1980 Regents of the University of California.
+  * All rights reserved.
+  *
+  * Redistribution and use in source and binary forms are permitted
+  * provided that the above copyright notice and this paragraph are
+  * duplicated in all such forms and that any documentation,
+  * advertising materials, and other materials related to such
+  * distribution and use acknowledge that the software was developed
+  * by the University of California, Berkeley.  The name of the
+  * University may not be used to endorse or promote products derived
+  * from this software without specific prior written permission.
+  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+  */
+ 
  #include "rh.h"
  #include <sys/types.h>
  #include <sys/stat.h>
***************
*** 75,108 ****
   *
   */
  
  c_star(i)
! long i;
  {
  
! 	register int ri,ii;
! 	
! 	if( Starbuf[i]=='*') {
! 		ii=strlen(fname)-1;
! 		ri=strlen(Starbuf+i)-1+i;
! 		while( fname[ii]==Starbuf[ri] && ri>i ) {
! 			ri--; ii--;
  		}
- 		Stack[SP++] = (ri==i);
  	}
- 	else {
- 		int x=0;
- 		ii=0;
- 		while( fname[x] ) {
- 			if(fname[x]=='/') ii=x;
- 			x++;
- 		}
- 		ii++;
- 		ri=i;
- 		while( fname[ii]==Starbuf[ri] && Starbuf[ri]!='*' 
- 			&& fname[ii] && Starbuf[ri]) {
- 			ri++; ii++;
- 		}
- 		Stack[SP++]=!(fname[ii]+Starbuf[ri]) || Starbuf[ri]=='*';
- 	}
  }
- 
--- 93,172 ----
   *
   */
  
+ static int Gmatch();
+ 
  c_star(i)
! 	long i;
  {
+ 	char *p;
+ 	extern char *rindex();
+ 	if ((p = rindex(fname, '/')) != 0)
+ 		p++;
+ 	else
+ 		p = fname;
+ 	Stack[SP++] = Gmatch(p, &Starbuf[i]);
+ }
  
! static
! Gmatch(s, p)
! 	register char *s, *p;
! {
! 	register int scc;
! 	int ok, lc;
! 	int c, cc;
! 
! 	for (;;) {
! 		scc = *s++;
! 		switch (c = *p++) {
! 
! 		case '[':
! 			ok = 0;
! 			lc = 077777;
! 			while (cc = *p++) {
! 				if (cc == ']') {
! 					if (ok)
! 						break;
! 					return (0);
! 				}
! 				if (cc == '-') {
! 					if (lc <= scc && scc <= *p++)
! 						ok++;
! 				} else
! 					if (scc == (lc = cc))
! 						ok++;
! 			}
! 			if (cc == 0)
! 				if (ok)
! 					p--;
! 				else
! 					return 0;
! 			continue;
! 
! 		case '*':
! 			if (!*p)
! 				return (1);
! 			for (s--; *s; s++)
! 				if (Gmatch(s, p))
! 					return (1);
! 			return (0);
! 
! 		case 0:
! 			return (scc == 0);
! 
! 		default:
! 			if (c != scc)
! 				return (0);
! 			continue;
! 
! 		case '?':
! 			if (scc == 0)
! 				return (0);
! 			continue;
! 
! 		case '\\':
! 			if (*p++ != scc)
! 				return (0);
! 			continue;
  		}
  	}
  }
===================================================================
RCS file: rhparse.c,v
retrieving revision 1.1
diff -c -r1.1 rhparse.c
*** /tmp/,RCSt1a01638	Wed May  3 18:30:09 1989
--- rhparse.c	Wed May  3 17:13:54 1989
***************
*** 459,471 ****
  	}
  
  	if( c == '"' ) {
! 		int index,st=0;
  		index=starfree;
! 		while( (c=getit())!= '"' ) {
  			if( starfree > STARLEN )
  				error("no more string space");
- 			if(c=='*') st++;
- 			if(st>1) error("too many *'s present");
  			Starbuf[starfree++]=c;
  		}
  		Starbuf[starfree++]='\0';
--- 459,470 ----
  	}
  
  	if( c == '"' ) {
! 		int index,st=0,quoted=0;
  		index=starfree;
! 		while( (c=getit())!= '"' || quoted ) {
! 			quoted = (c == '\\' && !quoted);
  			if( starfree > STARLEN )
  				error("no more string space");
  			Starbuf[starfree++]=c;
  		}
  		Starbuf[starfree++]='\0';

Rob
-- 
UUCP:   ...!mcvax!ukc!warwick!cudcv	PHONE:  +44 203 523037
JANET:  cudcv@uk.ac.warwick             ARPA:   cudcv@warwick.ac.uk
Rob McMahon, Computing Services, Warwick University, Coventry CV4 7AL, England

cudcv@warwick.ac.uk (Rob McMahon) (05/04/89)

In fact the more I thought about it the more it seemed like "..." meaning
shell syntax and "/.../" meaning a regular expression seemed like a good idea,
so with the aid of the FSF regular expression routines I offer you this.  It
makes the assumption that you're not going to put a `/' in your pattern, and
you will have to add regex.o to the list of dependencies in the Makefile.  If
characters are unsigned by default on your machine, you will have to add
`"-DSIGN_EXTEND_CHAR(x)=((signed char)(x))"' to CFLAGS if your compiler
understands `signed char', or `"-DSIGN_EXTEND_CHAR(x)=(((int)(x) << 24) >>
24)"' if not (assuming a 32 bit machine and 8 bit chars).

(This assumes you've already applied my previous patches.)

RCS file: rh.man,v
retrieving revision 1.2
diff -c -r1.2 rh.man
*** /tmp/,RCSt1a01763	Wed May  3 21:05:12 1989
--- rh.man	Wed May  3 20:37:49 1989
***************
*** 181,187 ****
  "expression".
  .I expression
  may contain the normal `*', `?', and `[' shell metacharacters, which can be
! quoted with `\e'.  When doing comparisons, only the base name is examined, not
  pathnames.
  .PP
  .IP [yyyy/mm/dd]
--- 181,188 ----
  "expression".
  .I expression
  may contain the normal `*', `?', and `[' shell metacharacters, which can be
! quoted with `\e', or may be a regular expression surrounded by slashes
! `"/\fI<re>\R/"'.  When doing comparisons, only the base name is examined, not
  pathnames.
  .PP
  .IP [yyyy/mm/dd]
===================================================================
RCS file: rhcmds.c,v
retrieving revision 1.4
diff -c -r1.4 rhcmds.c
*** /tmp/,RCSt1a01782	Wed May  3 21:18:50 1989
--- rhcmds.c	Wed May  3 21:13:08 1989
***************
*** 95,110 ****
  
  static int Gmatch();
  
  c_star(i)
  	long i;
  {
! 	char *p;
! 	extern char *rindex();
! 	if ((p = rindex(fname, '/')) != 0)
! 		p++;
  	else
! 		p = fname;
! 	Stack[SP++] = Gmatch(p, &Starbuf[i]);
  }
  
  static
--- 95,135 ----
  
  static int Gmatch();
  
+ static long last_re = -1;
+ 
  c_star(i)
  	long i;
  {
! 	char *base, *p;
! 	extern char *rindex(), *re_comp();
! 
! 	if ((base = rindex(fname, '/')) != 0)
! 		base++;
  	else
! 		base = fname;
! 	if (Starbuf[i] == '/') {
! 		/* no need to recompile if it''s the same re as last time */
! 		if (i != last_re) {
! 			/* blat the '/' at the end of the re.
! 			 * assume here that no-one is going to use \/, since
! 			 * there's no way to have a / in a filename in Unix
! 			 */
! 			p = &Starbuf[i];
! 			while (*p)
! 				p++;
! 			if (p[-1] == '/')
! 				p[-1] = '\0';
! 			/* +1 to skip the initial / */
! 			if ((p = re_comp(&Starbuf[i+1])) != 0)
! 				error(p);
! 			last_re = i;
! 		}
! 		if ((i = re_exec(base)) == -1)
! 			error("RE Internal Error");
! 		Stack[SP++] = i;
! 	}
! 	else
! 		Stack[SP++] = Gmatch(base, &Starbuf[i]);
  }
  
  static
===================================================================
*** /dev/null	Tue May  2 09:11:35 1989
--- regex.c	Wed May  3 18:51:14 1989
***************
*** 0 ****
--- 1,1736 ----
+ /* Extended regular expression matching and search library.
+    Copyright (C) 1985, 1989 Free Software Foundation, Inc.
+ 
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 1, or (at your option)
+    any later version.
+ 
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+ 
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ 
+ 
+    In other words, you are welcome to use, share and improve this program.
+    You are forbidden to forbid anyone else to use, share and improve
+    what you give them.   Help stamp out software-hoarding!  */
+ 
+ 
+ /* To test, compile with -Dtest.
+  This Dtestable feature turns this into a self-contained program
+  which reads a pattern, describes how it compiles,
+  then reads a string and searches for it.  */
+ 
+ #ifdef emacs
+ 
+ /* The `emacs' switch turns on certain special matching commands
+  that make sense only in emacs. */
+ 
+ #include "config.h"
+ #include "lisp.h"
+ #include "buffer.h"
+ #include "syntax.h"
+ 
+ #else  /* not emacs */
+ 
+ #ifdef USG
+ #define bcopy(s,d,n)	memcpy((d),(s),(n))
+ #define bcmp(s1,s2,n)	memcmp((s1),(s2),(n))
+ #define bzero(s,n)	memset((s),0,(n))
+ #endif
+ 
+ /* Make alloca work the best possible way.  */
+ #ifdef __GNUC__
+ #define alloca __builtin_alloca
+ #else
+ #ifdef sparc
+ #include <alloca.h>
+ #endif
+ #endif
+ 
+ /*
+  * Define the syntax stuff, so we can do the \<...\> things.
+  */
+ 
+ #ifndef Sword /* must be non-zero in some of the tests below... */
+ #define Sword 1
+ #endif
+ 
+ #define SYNTAX(c) re_syntax_table[c]
+ 
+ #ifdef SYNTAX_TABLE
+ 
+ char *re_syntax_table;
+ 
+ #else
+ 
+ static char re_syntax_table[256];
+ 
+ static void
+ init_syntax_once ()
+ {
+    register int c;
+    static int done = 0;
+ 
+    if (done)
+      return;
+ 
+    bzero (re_syntax_table, sizeof re_syntax_table);
+ 
+    for (c = 'a'; c <= 'z'; c++)
+      re_syntax_table[c] = Sword;
+ 
+    for (c = 'A'; c <= 'Z'; c++)
+      re_syntax_table[c] = Sword;
+ 
+    for (c = '0'; c <= '9'; c++)
+      re_syntax_table[c] = Sword;
+ 
+    done = 1;
+ }
+ 
+ #endif /* SYNTAX_TABLE */
+ #endif /* not emacs */
+ 
+ #include "regex.h"
+ 
+ /* Number of failure points to allocate space for initially,
+  when matching.  If this number is exceeded, more space is allocated,
+  so it is not a hard limit.  */
+ 
+ #ifndef NFAILURES
+ #define NFAILURES 80
+ #endif /* NFAILURES */
+ 
+ /* width of a byte in bits */
+ 
+ #define BYTEWIDTH 8
+ 
+ #ifndef SIGN_EXTEND_CHAR
+ #define SIGN_EXTEND_CHAR(x) (x)
+ #endif
+ 
+ static int obscure_syntax = 0;
+ 
+ /* Specify the precise syntax of regexp for compilation.
+    This provides for compatibility for various utilities
+    which historically have different, incompatible syntaxes.
+ 
+    The argument SYNTAX is a bit-mask containing the two bits
+    RE_NO_BK_PARENS and RE_NO_BK_VBAR.  */
+ 
+ int
+ re_set_syntax (syntax)
+ {
+   int ret;
+ 
+   ret = obscure_syntax;
+   obscure_syntax = syntax;
+   return ret;
+ }
+ 
+ /* re_compile_pattern takes a regular-expression string
+    and converts it into a buffer full of byte commands for matching.
+ 
+   PATTERN   is the address of the pattern string
+   SIZE      is the length of it.
+   BUFP	    is a  struct re_pattern_buffer *  which points to the info
+ 	    on where to store the byte commands.
+ 	    This structure contains a  char *  which points to the
+ 	    actual space, which should have been obtained with malloc.
+ 	    re_compile_pattern may use  realloc  to grow the buffer space.
+ 
+   The number of bytes of commands can be found out by looking in
+   the  struct re_pattern_buffer  that bufp pointed to,
+   after re_compile_pattern returns.
+ */
+ 
+ #define PATPUSH(ch) (*b++ = (char) (ch))
+ 
+ #define PATFETCH(c) \
+  {if (p == pend) goto end_of_pattern; \
+   c = * (unsigned char *) p++; \
+   if (translate) c = translate[c]; }
+ 
+ #define PATFETCH_RAW(c) \
+  {if (p == pend) goto end_of_pattern; \
+   c = * (unsigned char *) p++; }
+ 
+ #define PATUNFETCH p--
+ 
+ #define EXTEND_BUFFER \
+   { char *old_buffer = bufp->buffer; \
+     if (bufp->allocated == (1<<16)) goto too_big; \
+     bufp->allocated *= 2; \
+     if (bufp->allocated > (1<<16)) bufp->allocated = (1<<16); \
+     if (!(bufp->buffer = (char *) realloc (bufp->buffer, bufp->allocated))) \
+       goto memory_exhausted; \
+     c = bufp->buffer - old_buffer; \
+     b += c; \
+     if (fixup_jump) \
+       fixup_jump += c; \
+     if (laststart) \
+       laststart += c; \
+     begalt += c; \
+     if (pending_exact) \
+       pending_exact += c; \
+   }
+ 
+ static int store_jump (), insert_jump ();
+ 
+ char *
+ re_compile_pattern (pattern, size, bufp)
+      char *pattern;
+      int size;
+      struct re_pattern_buffer *bufp;
+ {
+   register char *b = bufp->buffer;
+   register char *p = pattern;
+   char *pend = pattern + size;
+   register unsigned c, c1;
+   char *p1;
+   unsigned char *translate = (unsigned char *) bufp->translate;
+ 
+   /* address of the count-byte of the most recently inserted "exactn" command.
+     This makes it possible to tell whether a new exact-match character
+     can be added to that command or requires a new "exactn" command. */
+      
+   char *pending_exact = 0;
+ 
+   /* address of the place where a forward-jump should go
+     to the end of the containing expression.
+     Each alternative of an "or", except the last, ends with a forward-jump
+     of this sort. */
+ 
+   char *fixup_jump = 0;
+ 
+   /* address of start of the most recently finished expression.
+     This tells postfix * where to find the start of its operand. */
+ 
+   char *laststart = 0;
+ 
+   /* In processing a repeat, 1 means zero matches is allowed */
+ 
+   char zero_times_ok;
+ 
+   /* In processing a repeat, 1 means many matches is allowed */
+ 
+   char many_times_ok;
+ 
+   /* address of beginning of regexp, or inside of last \( */
+ 
+   char *begalt = b;
+ 
+   /* Stack of information saved by \( and restored by \).
+      Four stack elements are pushed by each \(:
+        First, the value of b.
+        Second, the value of fixup_jump.
+        Third, the value of regnum.
+        Fourth, the value of begalt.  */
+ 
+   int stackb[40];
+   int *stackp = stackb;
+   int *stacke = stackb + 40;
+   int *stackt;
+ 
+   /* Counts \('s as they are encountered.  Remembered for the matching \),
+      where it becomes the "register number" to put in the stop_memory command */
+ 
+   int regnum = 1;
+ 
+   bufp->fastmap_accurate = 0;
+ 
+ #ifndef emacs
+ #ifndef SYNTAX_TABLE
+   /*
+    * Initialize the syntax table.
+    */
+    init_syntax_once();
+ #endif
+ #endif
+ 
+   if (bufp->allocated == 0)
+     {
+       bufp->allocated = 28;
+       if (bufp->buffer)
+ 	/* EXTEND_BUFFER loses when bufp->allocated is 0 */
+ 	bufp->buffer = (char *) realloc (bufp->buffer, 28);
+       else
+ 	/* Caller did not allocate a buffer.  Do it for him */
+ 	bufp->buffer = (char *) malloc (28);
+       if (!bufp->buffer) goto memory_exhausted;
+       begalt = b = bufp->buffer;
+     }
+ 
+   while (p != pend)
+     {
+       if (b - bufp->buffer > bufp->allocated - 10)
+ 	/* Note that EXTEND_BUFFER clobbers c */
+ 	EXTEND_BUFFER;
+ 
+       PATFETCH (c);
+ 
+       switch (c)
+ 	{
+ 	case '$':
+ 	  if (obscure_syntax & RE_TIGHT_VBAR)
+ 	    {
+ 	      if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS) && p != pend)
+ 		goto normal_char;
+ 	      /* Make operand of last vbar end before this `$'.  */
+ 	      if (fixup_jump)
+ 		store_jump (fixup_jump, jump, b);
+ 	      fixup_jump = 0;
+ 	      PATPUSH (endline);
+ 	      break;
+ 	    }
+ 
+ 	  /* $ means succeed if at end of line, but only in special contexts.
+ 	    If randomly in the middle of a pattern, it is a normal character. */
+ 	  if (p == pend || *p == '\n'
+ 	      || (obscure_syntax & RE_CONTEXT_INDEP_OPS)
+ 	      || (obscure_syntax & RE_NO_BK_PARENS
+ 		  ? *p == ')'
+ 		  : *p == '\\' && p[1] == ')')
+ 	      || (obscure_syntax & RE_NO_BK_VBAR
+ 		  ? *p == '|'
+ 		  : *p == '\\' && p[1] == '|'))
+ 	    {
+ 	      PATPUSH (endline);
+ 	      break;
+ 	    }
+ 	  goto normal_char;
+ 
+ 	case '^':
+ 	  /* ^ means succeed if at beg of line, but only if no preceding pattern. */
+ 
+ 	  if (laststart && p[-2] != '\n'
+ 	      && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS))
+ 	    goto normal_char;
+ 	  if (obscure_syntax & RE_TIGHT_VBAR)
+ 	    {
+ 	      if (p != pattern + 1
+ 		  && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS))
+ 		goto normal_char;
+ 	      PATPUSH (begline);
+ 	      begalt = b;
+ 	    }
+ 	  else
+ 	    PATPUSH (begline);
+ 	  break;
+ 
+ 	case '+':
+ 	case '?':
+ 	  if (obscure_syntax & RE_BK_PLUS_QM)
+ 	    goto normal_char;
+ 	handle_plus:
+ 	case '*':
+ 	  /* If there is no previous pattern, char not special. */
+ 	  if (!laststart && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS))
+ 	    goto normal_char;
+ 	  /* If there is a sequence of repetition chars,
+ 	     collapse it down to equivalent to just one.  */
+ 	  zero_times_ok = 0;
+ 	  many_times_ok = 0;
+ 	  while (1)
+ 	    {
+ 	      zero_times_ok |= c != '+';
+ 	      many_times_ok |= c != '?';
+ 	      if (p == pend)
+ 		break;
+ 	      PATFETCH (c);
+ 	      if (c == '*')
+ 		;
+ 	      else if (!(obscure_syntax & RE_BK_PLUS_QM)
+ 		       && (c == '+' || c == '?'))
+ 		;
+ 	      else if ((obscure_syntax & RE_BK_PLUS_QM)
+ 		       && c == '\\')
+ 		{
+ 		  int c1;
+ 		  PATFETCH (c1);
+ 		  if (!(c1 == '+' || c1 == '?'))
+ 		    {
+ 		      PATUNFETCH;
+ 		      PATUNFETCH;
+ 		      break;
+ 		    }
+ 		  c = c1;
+ 		}
+ 	      else
+ 		{
+ 		  PATUNFETCH;
+ 		  break;
+ 		}
+ 	    }
+ 
+ 	  /* Star, etc. applied to an empty pattern is equivalent
+ 	     to an empty pattern.  */
+ 	  if (!laststart)
+ 	    break;
+ 
+ 	  /* Now we know whether 0 matches is allowed,
+ 	     and whether 2 or more matches is allowed.  */
+ 	  if (many_times_ok)
+ 	    {
+ 	      /* If more than one repetition is allowed,
+ 		 put in a backward jump at the end.  */
+ 	      store_jump (b, maybe_finalize_jump, laststart - 3);
+ 	      b += 3;
+ 	    }
+ 	  insert_jump (on_failure_jump, laststart, b + 3, b);
+ 	  pending_exact = 0;
+ 	  b += 3;
+ 	  if (!zero_times_ok)
+ 	    {
+ 	      /* At least one repetition required: insert before the loop
+ 		 a skip over the initial on-failure-jump instruction */
+ 	      insert_jump (dummy_failure_jump, laststart, laststart + 6, b);
+ 	      b += 3;
+ 	    }
+ 	  break;
+ 
+ 	case '.':
+ 	  laststart = b;
+ 	  PATPUSH (anychar);
+ 	  break;
+ 
+ 	case '[':
+ 	  while (b - bufp->buffer
+ 		 > bufp->allocated - 3 - (1 << BYTEWIDTH) / BYTEWIDTH)
+ 	    /* Note that EXTEND_BUFFER clobbers c */
+ 	    EXTEND_BUFFER;
+ 
+ 	  laststart = b;
+ 	  if (*p == '^')
+ 	    PATPUSH (charset_not), p++;
+ 	  else
+ 	    PATPUSH (charset);
+ 	  p1 = p;
+ 
+ 	  PATPUSH ((1 << BYTEWIDTH) / BYTEWIDTH);
+ 	  /* Clear the whole map */
+ 	  bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);
+ 	  /* Read in characters and ranges, setting map bits */
+ 	  while (1)
+ 	    {
+ 	      PATFETCH (c);
+ 	      if (c == ']' && p != p1 + 1) break;
+ 	      if (*p == '-' && p[1] != ']')
+ 		{
+ 		  PATFETCH (c1);
+ 		  PATFETCH (c1);
+ 		  while (c <= c1)
+ 		    b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH), c++;
+ 		}
+ 	      else
+ 		{
+ 		  b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH);
+ 		}
+ 	    }
+ 	  /* Discard any bitmap bytes that are all 0 at the end of the map.
+ 	     Decrement the map-length byte too. */
+ 	  while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
+ 	    b[-1]--;
+ 	  b += b[-1];
+ 	  break;
+ 
+ 	case '(':
+ 	  if (! (obscure_syntax & RE_NO_BK_PARENS))
+ 	    goto normal_char;
+ 	  else
+ 	    goto handle_open;
+ 
+ 	case ')':
+ 	  if (! (obscure_syntax & RE_NO_BK_PARENS))
+ 	    goto normal_char;
+ 	  else
+ 	    goto handle_close;
+ 
+ 	case '\n':
+ 	  if (! (obscure_syntax & RE_NEWLINE_OR))
+ 	    goto normal_char;
+ 	  else
+ 	    goto handle_bar;
+ 
+ 	case '|':
+ 	  if (! (obscure_syntax & RE_NO_BK_VBAR))
+ 	    goto normal_char;
+ 	  else
+ 	    goto handle_bar;
+ 
+         case '\\':
+ 	  if (p == pend) goto invalid_pattern;
+ 	  PATFETCH_RAW (c);
+ 	  switch (c)
+ 	    {
+ 	    case '(':
+ 	      if (obscure_syntax & RE_NO_BK_PARENS)
+ 		goto normal_backsl;
+ 	    handle_open:
+ 	      if (stackp == stacke) goto nesting_too_deep;
+ 	      if (regnum < RE_NREGS)
+ 	        {
+ 		  PATPUSH (start_memory);
+ 		  PATPUSH (regnum);
+ 	        }
+ 	      *stackp++ = b - bufp->buffer;
+ 	      *stackp++ = fixup_jump ? fixup_jump - bufp->buffer + 1 : 0;
+ 	      *stackp++ = regnum++;
+ 	      *stackp++ = begalt - bufp->buffer;
+ 	      fixup_jump = 0;
+ 	      laststart = 0;
+ 	      begalt = b;
+ 	      break;
+ 
+ 	    case ')':
+ 	      if (obscure_syntax & RE_NO_BK_PARENS)
+ 		goto normal_backsl;
+ 	    handle_close:
+ 	      if (stackp == stackb) goto unmatched_close;
+ 	      begalt = *--stackp + bufp->buffer;
+ 	      if (fixup_jump)
+ 		store_jump (fixup_jump, jump, b);
+ 	      if (stackp[-1] < RE_NREGS)
+ 		{
+ 		  PATPUSH (stop_memory);
+ 		  PATPUSH (stackp[-1]);
+ 		}
+ 	      stackp -= 2;
+ 	      fixup_jump = 0;
+ 	      if (*stackp)
+ 		fixup_jump = *stackp + bufp->buffer - 1;
+ 	      laststart = *--stackp + bufp->buffer;
+ 	      break;
+ 
+ 	    case '|':
+ 	      if (obscure_syntax & RE_NO_BK_VBAR)
+ 		goto normal_backsl;
+ 	    handle_bar:
+ 	      insert_jump (on_failure_jump, begalt, b + 6, b);
+ 	      pending_exact = 0;
+ 	      b += 3;
+ 	      if (fixup_jump)
+ 		store_jump (fixup_jump, jump, b);
+ 	      fixup_jump = b;
+ 	      b += 3;
+ 	      laststart = 0;
+ 	      begalt = b;
+ 	      break;
+ 
+ #ifdef emacs
+ 	    case '=':
+ 	      PATPUSH (at_dot);
+ 	      break;
+ 
+ 	    case 's':	
+ 	      laststart = b;
+ 	      PATPUSH (syntaxspec);
+ 	      PATFETCH (c);
+ 	      PATPUSH (syntax_spec_code[c]);
+ 	      break;
+ 
+ 	    case 'S':
+ 	      laststart = b;
+ 	      PATPUSH (notsyntaxspec);
+ 	      PATFETCH (c);
+ 	      PATPUSH (syntax_spec_code[c]);
+ 	      break;
+ #endif /* emacs */
+ 
+ 	    case 'w':
+ 	      laststart = b;
+ 	      PATPUSH (wordchar);
+ 	      break;
+ 
+ 	    case 'W':
+ 	      laststart = b;
+ 	      PATPUSH (notwordchar);
+ 	      break;
+ 
+ 	    case '<':
+ 	      PATPUSH (wordbeg);
+ 	      break;
+ 
+ 	    case '>':
+ 	      PATPUSH (wordend);
+ 	      break;
+ 
+ 	    case 'b':
+ 	      PATPUSH (wordbound);
+ 	      break;
+ 
+ 	    case 'B':
+ 	      PATPUSH (notwordbound);
+ 	      break;
+ 
+ 	    case '`':
+ 	      PATPUSH (begbuf);
+ 	      break;
+ 
+ 	    case '\'':
+ 	      PATPUSH (endbuf);
+ 	      break;
+ 
+ 	    case '1':
+ 	    case '2':
+ 	    case '3':
+ 	    case '4':
+ 	    case '5':
+ 	    case '6':
+ 	    case '7':
+ 	    case '8':
+ 	    case '9':
+ 	      c1 = c - '0';
+ 	      if (c1 >= regnum)
+ 		goto normal_char;
+ 	      for (stackt = stackp - 2;  stackt > stackb;  stackt -= 4)
+  		if (*stackt == c1)
+ 		  goto normal_char;
+ 	      laststart = b;
+ 	      PATPUSH (duplicate);
+ 	      PATPUSH (c1);
+ 	      break;
+ 
+ 	    case '+':
+ 	    case '?':
+ 	      if (obscure_syntax & RE_BK_PLUS_QM)
+ 		goto handle_plus;
+ 
+ 	    default:
+ 	    normal_backsl:
+ 	      /* You might think it would be useful for \ to mean
+ 		 not to translate; but if we don't translate it
+ 		 it will never match anything.  */
+ 	      if (translate) c = translate[c];
+ 	      goto normal_char;
+ 	    }
+ 	  break;
+ 
+ 	default:
+ 	normal_char:
+ 	  if (!pending_exact || pending_exact + *pending_exact + 1 != b
+ 	      || *pending_exact == 0177 || *p == '*' || *p == '^'
+ 	      || ((obscure_syntax & RE_BK_PLUS_QM)
+ 		  ? *p == '\\' && (p[1] == '+' || p[1] == '?')
+ 		  : (*p == '+' || *p == '?')))
+ 	    {
+ 	      laststart = b;
+ 	      PATPUSH (exactn);
+ 	      pending_exact = b;
+ 	      PATPUSH (0);
+ 	    }
+ 	  PATPUSH (c);
+ 	  (*pending_exact)++;
+ 	}
+     }
+ 
+   if (fixup_jump)
+     store_jump (fixup_jump, jump, b);
+ 
+   if (stackp != stackb) goto unmatched_open;
+ 
+   bufp->used = b - bufp->buffer;
+   return 0;
+ 
+  invalid_pattern:
+   return "Invalid regular expression";
+ 
+  unmatched_open:
+   return "Unmatched \\(";
+ 
+  unmatched_close:
+   return "Unmatched \\)";
+ 
+  end_of_pattern:
+   return "Premature end of regular expression";
+ 
+  nesting_too_deep:
+   return "Nesting too deep";
+ 
+  too_big:
+   return "Regular expression too big";
+ 
+  memory_exhausted:
+   return "Memory exhausted";
+ }
+ 
+ /* Store where `from' points a jump operation to jump to where `to' points.
+   `opcode' is the opcode to store. */
+ 
+ static int
+ store_jump (from, opcode, to)
+      char *from, *to;
+      char opcode;
+ {
+   from[0] = opcode;
+   from[1] = (to - (from + 3)) & 0377;
+   from[2] = (to - (from + 3)) >> 8;
+ }
+ 
+ /* Open up space at char FROM, and insert there a jump to TO.
+    CURRENT_END gives te end of the storage no in use,
+    so we know how much data to copy up.
+    OP is the opcode of the jump to insert.
+ 
+    If you call this function, you must zero out pending_exact.  */
+ 
+ static int
+ insert_jump (op, from, to, current_end)
+      char op;
+      char *from, *to, *current_end;
+ {
+   register char *pto = current_end + 3;
+   register char *pfrom = current_end;
+   while (pfrom != from)
+     *--pto = *--pfrom;
+   store_jump (from, op, to);
+ }
+ 
+ /* Given a pattern, compute a fastmap from it.
+  The fastmap records which of the (1 << BYTEWIDTH) possible characters
+  can start a string that matches the pattern.
+  This fastmap is used by re_search to skip quickly over totally implausible text.
+ 
+  The caller must supply the address of a (1 << BYTEWIDTH)-byte data area
+  as bufp->fastmap.
+  The other components of bufp describe the pattern to be used.  */
+ 
+ void
+ re_compile_fastmap (bufp)
+      struct re_pattern_buffer *bufp;
+ {
+   unsigned char *pattern = (unsigned char *) bufp->buffer;
+   int size = bufp->used;
+   register char *fastmap = bufp->fastmap;
+   register unsigned char *p = pattern;
+   register unsigned char *pend = pattern + size;
+   register int j, k;
+   unsigned char *translate = (unsigned char *) bufp->translate;
+ 
+   unsigned char *stackb[NFAILURES];
+   unsigned char **stackp = stackb;
+ 
+   bzero (fastmap, (1 << BYTEWIDTH));
+   bufp->fastmap_accurate = 1;
+   bufp->can_be_null = 0;
+       
+   while (p)
+     {
+       if (p == pend)
+ 	{
+ 	  bufp->can_be_null = 1;
+ 	  break;
+ 	}
+ #ifdef SWITCH_ENUM_BUG
+       switch ((int) ((enum regexpcode) *p++))
+ #else
+       switch ((enum regexpcode) *p++)
+ #endif
+ 	{
+ 	case exactn:
+ 	  if (translate)
+ 	    fastmap[translate[p[1]]] = 1;
+ 	  else
+ 	    fastmap[p[1]] = 1;
+ 	  break;
+ 
+         case begline:
+         case before_dot:
+ 	case at_dot:
+ 	case after_dot:
+ 	case begbuf:
+ 	case endbuf:
+ 	case wordbound:
+ 	case notwordbound:
+ 	case wordbeg:
+ 	case wordend:
+ 	  continue;
+ 
+ 	case endline:
+ 	  if (translate)
+ 	    fastmap[translate['\n']] = 1;
+ 	  else
+ 	    fastmap['\n'] = 1;
+ 	  if (bufp->can_be_null != 1)
+ 	    bufp->can_be_null = 2;
+ 	  break;
+ 
+ 	case finalize_jump:
+ 	case maybe_finalize_jump:
+ 	case jump:
+ 	case dummy_failure_jump:
+ 	  bufp->can_be_null = 1;
+ 	  j = *p++ & 0377;
+ 	  j += SIGN_EXTEND_CHAR (*(char *)p) << 8;
+ 	  p += j + 1;		/* The 1 compensates for missing ++ above */
+ 	  if (j > 0)
+ 	    continue;
+ 	  /* Jump backward reached implies we just went through
+ 	     the body of a loop and matched nothing.
+ 	     Opcode jumped to should be an on_failure_jump.
+ 	     Just treat it like an ordinary jump.
+ 	     For a * loop, it has pushed its failure point already;
+ 	     if so, discard that as redundant.  */
+ 	  if ((enum regexpcode) *p != on_failure_jump)
+ 	    continue;
+ 	  p++;
+ 	  j = *p++ & 0377;
+ 	  j += SIGN_EXTEND_CHAR (*(char *)p) << 8;
+ 	  p += j + 1;		/* The 1 compensates for missing ++ above */
+ 	  if (stackp != stackb && *stackp == p)
+ 	    stackp--;
+ 	  continue;
+ 	  
+ 	case on_failure_jump:
+ 	  j = *p++ & 0377;
+ 	  j += SIGN_EXTEND_CHAR (*(char *)p) << 8;
+ 	  p++;
+ 	  *++stackp = p + j;
+ 	  continue;
+ 
+ 	case start_memory:
+ 	case stop_memory:
+ 	  p++;
+ 	  continue;
+ 
+ 	case duplicate:
+ 	  bufp->can_be_null = 1;
+ 	  fastmap['\n'] = 1;
+ 	case anychar:
+ 	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+ 	    if (j != '\n')
+ 	      fastmap[j] = 1;
+ 	  if (bufp->can_be_null)
+ 	    return;
+ 	  /* Don't return; check the alternative paths
+ 	     so we can set can_be_null if appropriate.  */
+ 	  break;
+ 
+ 	case wordchar:
+ 	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+ 	    if (SYNTAX (j) == Sword)
+ 	      fastmap[j] = 1;
+ 	  break;
+ 
+ 	case notwordchar:
+ 	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+ 	    if (SYNTAX (j) != Sword)
+ 	      fastmap[j] = 1;
+ 	  break;
+ 
+ #ifdef emacs
+ 	case syntaxspec:
+ 	  k = *p++;
+ 	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+ 	    if (SYNTAX (j) == (enum syntaxcode) k)
+ 	      fastmap[j] = 1;
+ 	  break;
+ 
+ 	case notsyntaxspec:
+ 	  k = *p++;
+ 	  for (j = 0; j < (1 << BYTEWIDTH); j++)
+ 	    if (SYNTAX (j) != (enum syntaxcode) k)
+ 	      fastmap[j] = 1;
+ 	  break;
+ #endif /* emacs */
+ 
+ 	case charset:
+ 	  for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+ 	    if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
+ 	      {
+ 		if (translate)
+ 		  fastmap[translate[j]] = 1;
+ 		else
+ 		  fastmap[j] = 1;
+ 	      }
+ 	  break;
+ 
+ 	case charset_not:
+ 	  /* Chars beyond end of map must be allowed */
+ 	  for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
+ 	    if (translate)
+ 	      fastmap[translate[j]] = 1;
+ 	    else
+ 	      fastmap[j] = 1;
+ 
+ 	  for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
+ 	    if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
+ 	      {
+ 		if (translate)
+ 		  fastmap[translate[j]] = 1;
+ 		else
+ 		  fastmap[j] = 1;
+ 	      }
+ 	  break;
+ 	}
+ 
+       /* Get here means we have successfully found the possible starting characters
+ 	 of one path of the pattern.  We need not follow this path any farther.
+ 	 Instead, look at the next alternative remembered in the stack. */
+       if (stackp != stackb)
+ 	p = *stackp--;
+       else
+ 	break;
+     }
+ }
+ 
+ /* Like re_search_2, below, but only one string is specified. */
+ 
+ int
+ re_search (pbufp, string, size, startpos, range, regs)
+      struct re_pattern_buffer *pbufp;
+      char *string;
+      int size, startpos, range;
+      struct re_registers *regs;
+ {
+   return re_search_2 (pbufp, 0, 0, string, size, startpos, range, regs, size);
+ }
+ 
+ /* Like re_match_2 but tries first a match starting at index STARTPOS,
+    then at STARTPOS + 1, and so on.
+    RANGE is the number of places to try before giving up.
+    If RANGE is negative, the starting positions tried are
+     STARTPOS, STARTPOS - 1, etc.
+    It is up to the caller to make sure that range is not so large
+    as to take the starting position outside of the input strings.
+ 
+ The value returned is the position at which the match was found,
+  or -1 if no match was found,
+  or -2 if error (such as failure stack overflow).  */
+ 
+ int
+ re_search_2 (pbufp, string1, size1, string2, size2, startpos, range, regs, mstop)
+      struct re_pattern_buffer *pbufp;
+      char *string1, *string2;
+      int size1, size2;
+      int startpos;
+      register int range;
+      struct re_registers *regs;
+      int mstop;
+ {
+   register char *fastmap = pbufp->fastmap;
+   register unsigned char *translate = (unsigned char *) pbufp->translate;
+   int total = size1 + size2;
+   int val;
+ 
+   /* Update the fastmap now if not correct already */
+   if (fastmap && !pbufp->fastmap_accurate)
+     re_compile_fastmap (pbufp);
+   
+   /* Don't waste time in a long search for a pattern
+      that says it is anchored.  */
+   if (pbufp->used > 0 && (enum regexpcode) pbufp->buffer[0] == begbuf
+       && range > 0)
+     {
+       if (startpos > 0)
+ 	return -1;
+       else
+ 	range = 1;
+     }
+ 
+   while (1)
+     {
+       /* If a fastmap is supplied, skip quickly over characters
+ 	 that cannot possibly be the start of a match.
+ 	 Note, however, that if the pattern can possibly match
+ 	 the null string, we must test it at each starting point
+ 	 so that we take the first null string we get.  */
+ 
+       if (fastmap && startpos < total && pbufp->can_be_null != 1)
+ 	{
+ 	  if (range > 0)
+ 	    {
+ 	      register int lim = 0;
+ 	      register unsigned char *p;
+ 	      int irange = range;
+ 	      if (startpos < size1 && startpos + range >= size1)
+ 		lim = range - (size1 - startpos);
+ 
+ 	      p = ((unsigned char *)
+ 		   &(startpos >= size1 ? string2 - size1 : string1)[startpos]);
+ 
+ 	      if (translate)
+ 		{
+ 		  while (range > lim && !fastmap[translate[*p++]])
+ 		    range--;
+ 		}
+ 	      else
+ 		{
+ 		  while (range > lim && !fastmap[*p++])
+ 		    range--;
+ 		}
+ 	      startpos += irange - range;
+ 	    }
+ 	  else
+ 	    {
+ 	      register unsigned char c;
+ 	      if (startpos >= size1)
+ 		c = string2[startpos - size1];
+ 	      else
+ 		c = string1[startpos];
+ 	      c &= 0xff;
+ 	      if (translate ? !fastmap[translate[c]] : !fastmap[c])
+ 		goto advance;
+ 	    }
+ 	}
+ 
+       if (range >= 0 && startpos == total
+ 	  && fastmap && pbufp->can_be_null == 0)
+ 	return -1;
+ 
+       val = re_match_2 (pbufp, string1, size1, string2, size2, startpos, regs, mstop);
+       if (0 <= val)
+ 	{
+ 	  if (val == -2)
+ 	    return -2;
+ 	  return startpos;
+ 	}
+ 
+ #ifdef C_ALLOCA
+       alloca (0);
+ #endif /* C_ALLOCA */
+ 
+     advance:
+       if (!range) break;
+       if (range > 0) range--, startpos++; else range++, startpos--;
+     }
+   return -1;
+ }
+ 
+ #ifndef emacs   /* emacs never uses this */
+ int
+ re_match (pbufp, string, size, pos, regs)
+      struct re_pattern_buffer *pbufp;
+      char *string;
+      int size, pos;
+      struct re_registers *regs;
+ {
+   return re_match_2 (pbufp, 0, 0, string, size, pos, regs, size);
+ }
+ #endif /* emacs */
+ 
+ /* Maximum size of failure stack.  Beyond this, overflow is an error.  */
+ 
+ int re_max_failures = 2000;
+ 
+ static int bcmp_translate();
+ /* Match the pattern described by PBUFP
+    against data which is the virtual concatenation of STRING1 and STRING2.
+    SIZE1 and SIZE2 are the sizes of the two data strings.
+    Start the match at position POS.
+    Do not consider matching past the position MSTOP.
+ 
+    If pbufp->fastmap is nonzero, then it had better be up to date.
+ 
+    The reason that the data to match are specified as two components
+    which are to be regarded as concatenated
+    is so this function can be used directly on the contents of an Emacs buffer.
+ 
+    -1 is returned if there is no match.  -2 is returned if there is
+    an error (such as match stack overflow).  Otherwise the value is the length
+    of the substring which was matched.  */
+ 
+ int
+ re_match_2 (pbufp, string1, size1, string2, size2, pos, regs, mstop)
+      struct re_pattern_buffer *pbufp;
+      unsigned char *string1, *string2;
+      int size1, size2;
+      int pos;
+      struct re_registers *regs;
+      int mstop;
+ {
+   register unsigned char *p = (unsigned char *) pbufp->buffer;
+   register unsigned char *pend = p + pbufp->used;
+   /* End of first string */
+   unsigned char *end1;
+   /* End of second string */
+   unsigned char *end2;
+   /* Pointer just past last char to consider matching */
+   unsigned char *end_match_1, *end_match_2;
+   register unsigned char *d, *dend;
+   register int mcnt;
+   unsigned char *translate = (unsigned char *) pbufp->translate;
+ 
+  /* Failure point stack.  Each place that can handle a failure further down the line
+     pushes a failure point on this stack.  It consists of two char *'s.
+     The first one pushed is where to resume scanning the pattern;
+     the second pushed is where to resume scanning the strings.
+     If the latter is zero, the failure point is a "dummy".
+     If a failure happens and the innermost failure point is dormant,
+     it discards that failure point and tries the next one. */
+ 
+   unsigned char *initial_stack[2 * NFAILURES];
+   unsigned char **stackb = initial_stack;
+   unsigned char **stackp = stackb, **stacke = &stackb[2 * NFAILURES];
+ 
+   /* Information on the "contents" of registers.
+      These are pointers into the input strings; they record
+      just what was matched (on this attempt) by some part of the pattern.
+      The start_memory command stores the start of a register's contents
+      and the stop_memory command stores the end.
+ 
+      At that point, regstart[regnum] points to the first character in the register,
+      regend[regnum] points to the first character beyond the end of the register,
+      regstart_seg1[regnum] is true iff regstart[regnum] points into string1,
+      and regend_seg1[regnum] is true iff regend[regnum] points into string1.  */
+ 
+   unsigned char *regstart[RE_NREGS];
+   unsigned char *regend[RE_NREGS];
+   unsigned char regstart_seg1[RE_NREGS], regend_seg1[RE_NREGS];
+ 
+   /* Set up pointers to ends of strings.
+      Don't allow the second string to be empty unless both are empty.  */
+   if (!size2)
+     {
+       string2 = string1;
+       size2 = size1;
+       string1 = 0;
+       size1 = 0;
+     }
+   end1 = string1 + size1;
+   end2 = string2 + size2;
+ 
+   /* Compute where to stop matching, within the two strings */
+   if (mstop <= size1)
+     {
+       end_match_1 = string1 + mstop;
+       end_match_2 = string2;
+     }
+   else
+     {
+       end_match_1 = end1;
+       end_match_2 = string2 + mstop - size1;
+     }
+ 
+   /* Initialize \) text positions to -1
+      to mark ones that no \( or \) has been seen for.  */
+ 
+   for (mcnt = 0; mcnt < sizeof (regend) / sizeof (*regend); mcnt++)
+     regend[mcnt] = (unsigned char *) -1;
+ 
+   /* `p' scans through the pattern as `d' scans through the data.
+      `dend' is the end of the input string that `d' points within.
+      `d' is advanced into the following input string whenever necessary,
+      but this happens before fetching;
+      therefore, at the beginning of the loop,
+      `d' can be pointing at the end of a string,
+      but it cannot equal string2.  */
+ 
+   if (pos <= size1)
+     d = string1 + pos, dend = end_match_1;
+   else
+     d = string2 + pos - size1, dend = end_match_2;
+ 
+ /* Write PREFETCH; just before fetching a character with *d.  */
+ #define PREFETCH \
+  while (d == dend)						    \
+   { if (dend == end_match_2) goto fail;  /* end of string2 => failure */   \
+     d = string2;  /* end of string1 => advance to string2. */       \
+     dend = end_match_2; }
+ 
+   /* This loop loops over pattern commands.
+      It exits by returning from the function if match is complete,
+      or it drops through if match fails at this starting point in the input data. */
+ 
+   while (1)
+     {
+       if (p == pend)
+ 	/* End of pattern means we have succeeded! */
+ 	{
+ 	  /* If caller wants register contents data back, convert it to indices */
+ 	  if (regs)
+ 	    {
+  	      regs->start[0] = pos;
+  	      if (dend == end_match_1)
+  		regs->end[0] = d - string1;
+  	      else
+  		regs->end[0] = d - string2 + size1;
+  	      for (mcnt = 1; mcnt < RE_NREGS; mcnt++)
+ 		{
+ 		  if (regend[mcnt] == (unsigned char *) -1)
+ 		    {
+ 		      regs->start[mcnt] = -1;
+ 		      regs->end[mcnt] = -1;
+ 		      continue;
+ 		    }
+  		  if (regstart_seg1[mcnt])
+ 		    regs->start[mcnt] = regstart[mcnt] - string1;
+ 		  else
+ 		    regs->start[mcnt] = regstart[mcnt] - string2 + size1;
+  		  if (regend_seg1[mcnt])
+ 		    regs->end[mcnt] = regend[mcnt] - string1;
+ 		  else
+ 		    regs->end[mcnt] = regend[mcnt] - string2 + size1;
+ 		}
+ 	    }
+  	  if (dend == end_match_1)
+ 	    return (d - string1 - pos);
+ 	  else
+ 	    return d - string2 + size1 - pos;
+ 	}
+ 
+       /* Otherwise match next pattern command */
+ #ifdef SWITCH_ENUM_BUG
+       switch ((int) ((enum regexpcode) *p++))
+ #else
+       switch ((enum regexpcode) *p++)
+ #endif
+ 	{
+ 
+ 	/* \( is represented by a start_memory, \) by a stop_memory.
+ 	    Both of those commands contain a "register number" argument.
+ 	    The text matched within the \( and \) is recorded under that number.
+ 	    Then, \<digit> turns into a `duplicate' command which
+ 	    is followed by the numeric value of <digit> as the register number. */
+ 
+ 	case start_memory:
+ 	  regstart[*p] = d;
+  	  regstart_seg1[*p++] = (dend == end_match_1);
+ 	  break;
+ 
+ 	case stop_memory:
+ 	  regend[*p] = d;
+  	  regend_seg1[*p++] = (dend == end_match_1);
+ 	  break;
+ 
+ 	case duplicate:
+ 	  {
+ 	    int regno = *p++;   /* Get which register to match against */
+ 	    register unsigned char *d2, *dend2;
+ 
+ 	    d2 = regstart[regno];
+  	    dend2 = ((regstart_seg1[regno] == regend_seg1[regno])
+ 		     ? regend[regno] : end_match_1);
+ 	    while (1)
+ 	      {
+ 		/* Advance to next segment in register contents, if necessary */
+ 		while (d2 == dend2)
+ 		  {
+ 		    if (dend2 == end_match_2) break;
+ 		    if (dend2 == regend[regno]) break;
+ 		    d2 = string2, dend2 = regend[regno];  /* end of string1 => advance to string2. */
+ 		  }
+ 		/* At end of register contents => success */
+ 		if (d2 == dend2) break;
+ 
+ 		/* Advance to next segment in data being matched, if necessary */
+ 		PREFETCH;
+ 
+ 		/* mcnt gets # consecutive chars to compare */
+ 		mcnt = dend - d;
+ 		if (mcnt > dend2 - d2)
+ 		  mcnt = dend2 - d2;
+ 		/* Compare that many; failure if mismatch, else skip them. */
+ 		if (translate ? bcmp_translate (d, d2, mcnt, translate) : bcmp (d, d2, mcnt))
+ 		  goto fail;
+ 		d += mcnt, d2 += mcnt;
+ 	      }
+ 	  }
+ 	  break;
+ 
+ 	case anychar:
+ 	  /* fetch a data character */
+ 	  PREFETCH;
+ 	  /* Match anything but a newline.  */
+ 	  if ((translate ? translate[*d++] : *d++) == '\n')
+ 	    goto fail;
+ 	  break;
+ 
+ 	case charset:
+ 	case charset_not:
+ 	  {
+ 	    /* Nonzero for charset_not */
+ 	    int not = 0;
+ 	    register int c;
+ 	    if (*(p - 1) == (unsigned char) charset_not)
+ 	      not = 1;
+ 
+ 	    /* fetch a data character */
+ 	    PREFETCH;
+ 
+ 	    if (translate)
+ 	      c = translate [*d];
+ 	    else
+ 	      c = *d;
+ 
+ 	    if (c < *p * BYTEWIDTH
+ 		&& p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+ 	      not = !not;
+ 
+ 	    p += 1 + *p;
+ 
+ 	    if (!not) goto fail;
+ 	    d++;
+ 	    break;
+ 	  }
+ 
+ 	case begline:
+ 	  if (d == string1 || d[-1] == '\n')
+ 	    break;
+ 	  goto fail;
+ 
+ 	case endline:
+ 	  if (d == end2
+ 	      || (d == end1 ? (size2 == 0 || *string2 == '\n') : *d == '\n'))
+ 	    break;
+ 	  goto fail;
+ 
+ 	/* "or" constructs ("|") are handled by starting each alternative
+ 	    with an on_failure_jump that points to the start of the next alternative.
+ 	    Each alternative except the last ends with a jump to the joining point.
+ 	    (Actually, each jump except for the last one really jumps
+ 	     to the following jump, because tensioning the jumps is a hassle.) */
+ 
+ 	/* The start of a stupid repeat has an on_failure_jump that points
+ 	   past the end of the repeat text.
+ 	   This makes a failure point so that, on failure to match a repetition,
+ 	   matching restarts past as many repetitions have been found
+ 	   with no way to fail and look for another one.  */
+ 
+ 	/* A smart repeat is similar but loops back to the on_failure_jump
+ 	   so that each repetition makes another failure point. */
+ 
+ 	case on_failure_jump:
+ 	  if (stackp == stacke)
+ 	    {
+ 	      unsigned char **stackx;
+ 	      if (stacke - stackb > re_max_failures * 2)
+ 		return -2;
+ 	      stackx = (unsigned char **) alloca (2 * (stacke - stackb)
+ 					 * sizeof (char *));
+ 	      bcopy (stackb, stackx, (stacke - stackb) * sizeof (char *));
+ 	      stackp = stackx + (stackp - stackb);
+ 	      stacke = stackx + 2 * (stacke - stackb);
+ 	      stackb = stackx;
+ 	    }
+ 	  mcnt = *p++ & 0377;
+ 	  mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8;
+ 	  p++;
+ 	  *stackp++ = mcnt + p;
+ 	  *stackp++ = d;
+ 	  break;
+ 
+ 	/* The end of a smart repeat has an maybe_finalize_jump back.
+ 	   Change it either to a finalize_jump or an ordinary jump. */
+ 
+ 	case maybe_finalize_jump:
+ 	  mcnt = *p++ & 0377;
+ 	  mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8;
+ 	  p++;
+ 	  {
+ 	    register unsigned char *p2 = p;
+ 	    /* Compare what follows with the begining of the repeat.
+ 	       If we can establish that there is nothing that they would
+ 	       both match, we can change to finalize_jump */
+ 	    while (p2 != pend
+ 		   && (*p2 == (unsigned char) stop_memory
+ 		       || *p2 == (unsigned char) start_memory))
+ 	      p2++;
+ 	    if (p2 == pend)
+ 	      p[-3] = (unsigned char) finalize_jump;
+ 	    else if (*p2 == (unsigned char) exactn
+ 		     || *p2 == (unsigned char) endline)
+ 	      {
+ 		register int c = *p2 == (unsigned char) endline ? '\n' : p2[2];
+ 		register unsigned char *p1 = p + mcnt;
+ 		/* p1[0] ... p1[2] are an on_failure_jump.
+ 		   Examine what follows that */
+ 		if (p1[3] == (unsigned char) exactn && p1[5] != c)
+ 		  p[-3] = (unsigned char) finalize_jump;
+ 		else if (p1[3] == (unsigned char) charset
+ 			 || p1[3] == (unsigned char) charset_not)
+ 		  {
+ 		    int not = p1[3] == (unsigned char) charset_not;
+ 		    if (c < p1[4] * BYTEWIDTH
+ 			&& p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
+ 		      not = !not;
+ 		    /* not is 1 if c would match */
+ 		    /* That means it is not safe to finalize */
+ 		    if (!not)
+ 		      p[-3] = (unsigned char) finalize_jump;
+ 		  }
+ 	      }
+ 	  }
+ 	  p -= 2;
+ 	  if (p[-1] != (unsigned char) finalize_jump)
+ 	    {
+ 	      p[-1] = (unsigned char) jump;
+ 	      goto nofinalize;
+ 	    }
+ 
+ 	/* The end of a stupid repeat has a finalize-jump
+ 	   back to the start, where another failure point will be made
+ 	   which will point after all the repetitions found so far. */
+ 
+ 	case finalize_jump:
+ 	  stackp -= 2;
+ 
+ 	case jump:
+ 	nofinalize:
+ 	  mcnt = *p++ & 0377;
+ 	  mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8;
+ 	  p += mcnt + 1;	/* The 1 compensates for missing ++ above */
+ 	  break;
+ 
+ 	case dummy_failure_jump:
+ 	  if (stackp == stacke)
+ 	    {
+ 	      unsigned char **stackx
+ 		= (unsigned char **) alloca (2 * (stacke - stackb)
+ 					     * sizeof (char *));
+ 	      bcopy (stackb, stackx, (stacke - stackb) * sizeof (char *));
+ 	      stackp = stackx + (stackp - stackb);
+ 	      stacke = stackx + 2 * (stacke - stackb);
+ 	      stackb = stackx;
+ 	    }
+ 	  *stackp++ = 0;
+ 	  *stackp++ = 0;
+ 	  goto nofinalize;
+ 
+ 	case wordbound:
+ 	  if (d == string1  /* Points to first char */
+ 	      || d == end2  /* Points to end */
+ 	      || (d == end1 && size2 == 0)) /* Points to end */
+ 	    break;
+ 	  if ((SYNTAX (d[-1]) == Sword)
+ 	      != (SYNTAX (d == end1 ? *string2 : *d) == Sword))
+ 	    break;
+ 	  goto fail;
+ 
+ 	case notwordbound:
+ 	  if (d == string1  /* Points to first char */
+ 	      || d == end2  /* Points to end */
+ 	      || (d == end1 && size2 == 0)) /* Points to end */
+ 	    goto fail;
+ 	  if ((SYNTAX (d[-1]) == Sword)
+ 	      != (SYNTAX (d == end1 ? *string2 : *d) == Sword))
+ 	    goto fail;
+ 	  break;
+ 
+ 	case wordbeg:
+ 	  if (d == end2  /* Points to end */
+ 	      || (d == end1 && size2 == 0) /* Points to end */
+ 	      || SYNTAX (* (d == end1 ? string2 : d)) != Sword) /* Next char not a letter */
+ 	    goto fail;
+ 	  if (d == string1  /* Points to first char */
+ 	      || SYNTAX (d[-1]) != Sword)  /* prev char not letter */
+ 	    break;
+ 	  goto fail;
+ 
+ 	case wordend:
+ 	  if (d == string1  /* Points to first char */
+ 	      || SYNTAX (d[-1]) != Sword)  /* prev char not letter */
+ 	    goto fail;
+ 	  if (d == end2  /* Points to end */
+ 	      || (d == end1 && size2 == 0) /* Points to end */
+ 	      || SYNTAX (d == end1 ? *string2 : *d) != Sword) /* Next char not a letter */
+ 	    break;
+ 	  goto fail;
+ 
+ #ifdef emacs
+ 	case before_dot:
+ 	  if (((d - string2 <= (unsigned) size2)
+ 	       ? d - bf_p2 : d - bf_p1)
+ 	      <= point)
+ 	    goto fail;
+ 	  break;
+ 
+ 	case at_dot:
+ 	  if (((d - string2 <= (unsigned) size2)
+ 	       ? d - bf_p2 : d - bf_p1)
+ 	      == point)
+ 	    goto fail;
+ 	  break;
+ 
+ 	case after_dot:
+ 	  if (((d - string2 <= (unsigned) size2)
+ 	       ? d - bf_p2 : d - bf_p1)
+ 	      >= point)
+ 	    goto fail;
+ 	  break;
+ 
+ 	case wordchar:
+ 	  mcnt = (int) Sword;
+ 	  goto matchsyntax;
+ 
+ 	case syntaxspec:
+ 	  mcnt = *p++;
+ 	matchsyntax:
+ 	  PREFETCH;
+ 	  if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail;
+ 	  break;
+ 	  
+ 	case notwordchar:
+ 	  mcnt = (int) Sword;
+ 	  goto matchnotsyntax;
+ 
+ 	case notsyntaxspec:
+ 	  mcnt = *p++;
+ 	matchnotsyntax:
+ 	  PREFETCH;
+ 	  if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail;
+ 	  break;
+ #else
+ 	case wordchar:
+ 	  PREFETCH;
+ 	  if (SYNTAX (*d++) == 0) goto fail;
+ 	  break;
+ 	  
+ 	case notwordchar:
+ 	  PREFETCH;
+ 	  if (SYNTAX (*d++) != 0) goto fail;
+ 	  break;
+ #endif /* not emacs */
+ 
+ 	case begbuf:
+ 	  if (d == string1)	/* Note, d cannot equal string2 */
+ 	    break;		/* unless string1 == string2.  */
+ 	  goto fail;
+ 
+ 	case endbuf:
+ 	  if (d == end2 || (d == end1 && size2 == 0))
+ 	    break;
+ 	  goto fail;
+ 
+ 	case exactn:
+ 	  /* Match the next few pattern characters exactly.
+ 	     mcnt is how many characters to match. */
+ 	  mcnt = *p++;
+ 	  if (translate)
+ 	    {
+ 	      do
+ 		{
+ 		  PREFETCH;
+ 		  if (translate[*d++] != *p++) goto fail;
+ 		}
+ 	      while (--mcnt);
+ 	    }
+ 	  else
+ 	    {
+ 	      do
+ 		{
+ 		  PREFETCH;
+ 		  if (*d++ != *p++) goto fail;
+ 		}
+ 	      while (--mcnt);
+ 	    }
+ 	  break;
+ 	}
+       continue;    /* Successfully matched one pattern command; keep matching */
+ 
+       /* Jump here if any matching operation fails. */
+     fail:
+       if (stackp != stackb)
+ 	/* A restart point is known.  Restart there and pop it. */
+ 	{
+ 	  if (!stackp[-2])
+ 	    {   /* If innermost failure point is dormant, flush it and keep looking */
+ 	      stackp -= 2;
+ 	      goto fail;
+ 	    }
+ 	  d = *--stackp;
+ 	  p = *--stackp;
+ 	  if (d >= string1 && d <= end1)
+ 	    dend = end_match_1;
+ 	}
+       else break;   /* Matching at this starting point really fails! */
+     }
+   return -1;         /* Failure to match */
+ }
+ 
+ static int
+ bcmp_translate (s1, s2, len, translate)
+      unsigned char *s1, *s2;
+      register int len;
+      unsigned char *translate;
+ {
+   register unsigned char *p1 = s1, *p2 = s2;
+   while (len)
+     {
+       if (translate [*p1++] != translate [*p2++]) return 1;
+       len--;
+     }
+   return 0;
+ }
+ 
+ /* Entry points compatible with bsd4.2 regex library */
+ 
+ #ifndef emacs
+ 
+ static struct re_pattern_buffer re_comp_buf;
+ 
+ char *
+ re_comp (s)
+      char *s;
+ {
+   if (!s)
+     {
+       if (!re_comp_buf.buffer)
+ 	return "No previous regular expression";
+       return 0;
+     }
+ 
+   if (!re_comp_buf.buffer)
+     {
+       if (!(re_comp_buf.buffer = (char *) malloc (200)))
+ 	return "Memory exhausted";
+       re_comp_buf.allocated = 200;
+       if (!(re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH)))
+ 	return "Memory exhausted";
+     }
+   return re_compile_pattern (s, strlen (s), &re_comp_buf);
+ }
+ 
+ int
+ re_exec (s)
+      char *s;
+ {
+   int len = strlen (s);
+   return 0 <= re_search (&re_comp_buf, s, len, 0, len, 0);
+ }
+ 
+ #endif /* emacs */
+ 
+ #ifdef test
+ 
+ #include <stdio.h>
+ 
+ /* Indexed by a character, gives the upper case equivalent of the character */
+ 
+ static char upcase[0400] = 
+   { 000, 001, 002, 003, 004, 005, 006, 007,
+     010, 011, 012, 013, 014, 015, 016, 017,
+     020, 021, 022, 023, 024, 025, 026, 027,
+     030, 031, 032, 033, 034, 035, 036, 037,
+     040, 041, 042, 043, 044, 045, 046, 047,
+     050, 051, 052, 053, 054, 055, 056, 057,
+     060, 061, 062, 063, 064, 065, 066, 067,
+     070, 071, 072, 073, 074, 075, 076, 077,
+     0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107,
+     0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+     0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127,
+     0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137,
+     0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107,
+     0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117,
+     0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127,
+     0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177,
+     0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207,
+     0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217,
+     0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227,
+     0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237,
+     0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247,
+     0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257,
+     0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267,
+     0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277,
+     0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307,
+     0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317,
+     0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327,
+     0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337,
+     0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347,
+     0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357,
+     0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367,
+     0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377
+   };
+ 
+ main (argc, argv)
+      int argc;
+      char **argv;
+ {
+   char pat[80];
+   struct re_pattern_buffer buf;
+   int i;
+   char c;
+   char fastmap[(1 << BYTEWIDTH)];
+ 
+   /* Allow a command argument to specify the style of syntax.  */
+   if (argc > 1)
+     obscure_syntax = atoi (argv[1]);
+ 
+   buf.allocated = 40;
+   buf.buffer = (char *) malloc (buf.allocated);
+   buf.fastmap = fastmap;
+   buf.translate = upcase;
+ 
+   while (1)
+     {
+       gets (pat);
+ 
+       if (*pat)
+ 	{
+           re_compile_pattern (pat, strlen(pat), &buf);
+ 
+ 	  for (i = 0; i < buf.used; i++)
+ 	    printchar (buf.buffer[i]);
+ 
+ 	  putchar ('\n');
+ 
+ 	  printf ("%d allocated, %d used.\n", buf.allocated, buf.used);
+ 
+ 	  re_compile_fastmap (&buf);
+ 	  printf ("Allowed by fastmap: ");
+ 	  for (i = 0; i < (1 << BYTEWIDTH); i++)
+ 	    if (fastmap[i]) printchar (i);
+ 	  putchar ('\n');
+ 	}
+ 
+       gets (pat);	/* Now read the string to match against */
+ 
+       i = re_match (&buf, pat, strlen (pat), 0, 0);
+       printf ("Match value %d.\n", i);
+     }
+ }
+ 
+ #ifdef NOTDEF
+ print_buf (bufp)
+      struct re_pattern_buffer *bufp;
+ {
+   int i;
+ 
+   printf ("buf is :\n----------------\n");
+   for (i = 0; i < bufp->used; i++)
+     printchar (bufp->buffer[i]);
+   
+   printf ("\n%d allocated, %d used.\n", bufp->allocated, bufp->used);
+   
+   printf ("Allowed by fastmap: ");
+   for (i = 0; i < (1 << BYTEWIDTH); i++)
+     if (bufp->fastmap[i])
+       printchar (i);
+   printf ("\nAllowed by translate: ");
+   if (bufp->translate)
+     for (i = 0; i < (1 << BYTEWIDTH); i++)
+       if (bufp->translate[i])
+ 	printchar (i);
+   printf ("\nfastmap is%s accurate\n", bufp->fastmap_accurate ? "" : "n't");
+   printf ("can %s be null\n----------", bufp->can_be_null ? "" : "not");
+ }
+ #endif
+ 
+ printchar (c)
+      char c;
+ {
+   if (c < 041 || c >= 0177)
+     {
+       putchar ('\\');
+       putchar (((c >> 6) & 3) + '0');
+       putchar (((c >> 3) & 7) + '0');
+       putchar ((c & 7) + '0');
+     }
+   else
+     putchar (c);
+ }
+ 
+ error (string)
+      char *string;
+ {
+   puts (string);
+   exit (1);
+ }
+ 
+ #endif /* test */
========================================================================
*** /dev/null	Tue May  2 09:11:35 1989
--- regex.h	Wed May  3 18:51:15 1989
***************
*** 0 ****
--- 1,185 ----
+ /* Definitions for data structures callers pass the regex library.
+    Copyright (C) 1985, 1989 Free Software Foundation, Inc.
+ 
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 1, or (at your option)
+    any later version.
+ 
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+ 
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ 
+ 
+    In other words, you are welcome to use, share and improve this program.
+    You are forbidden to forbid anyone else to use, share and improve
+    what you give them.   Help stamp out software-hoarding!  */
+ 
+ 
+ /* Define number of parens for which we record the beginnings and ends.
+    This affects how much space the `struct re_registers' type takes up.  */
+ #ifndef RE_NREGS
+ #define RE_NREGS 10
+ #endif
+ 
+ /* These bits are used in the obscure_syntax variable to choose among
+    alternative regexp syntaxes.  */
+ 
+ /* 1 means plain parentheses serve as grouping, and backslash
+      parentheses are needed for literal searching.
+    0 means backslash-parentheses are grouping, and plain parentheses
+      are for literal searching.  */
+ #define RE_NO_BK_PARENS 1
+ 
+ /* 1 means plain | serves as the "or"-operator, and \| is a literal.
+    0 means \| serves as the "or"-operator, and | is a literal.  */
+ #define RE_NO_BK_VBAR 2
+ 
+ /* 0 means plain + or ? serves as an operator, and \+, \? are literals.
+    1 means \+, \? are operators and plain +, ? are literals.  */
+ #define RE_BK_PLUS_QM 4
+ 
+ /* 1 means | binds tighter than ^ or $.
+    0 means the contrary.  */
+ #define RE_TIGHT_VBAR 8
+ 
+ /* 1 means treat \n as an _OR operator
+    0 means treat it as a normal character */
+ #define RE_NEWLINE_OR 16
+ 
+ /* 0 means that a special characters (such as *, ^, and $) always have
+      their special meaning regardless of the surrounding context.
+    1 means that special characters may act as normal characters in some
+      contexts.  Specifically, this applies to:
+ 	^ - only special at the beginning, or after ( or |
+ 	$ - only special at the end, or before ) or |
+ 	*, +, ? - only special when not after the beginning, (, or | */
+ #define RE_CONTEXT_INDEP_OPS 32
+ 
+ /* Now define combinations of bits for the standard possibilities.  */
+ #define RE_SYNTAX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR | RE_CONTEXT_INDEP_OPS)
+ #define RE_SYNTAX_EGREP (RE_SYNTAX_AWK | RE_NEWLINE_OR)
+ #define RE_SYNTAX_GREP (RE_BK_PLUS_QM | RE_NEWLINE_OR)
+ #define RE_SYNTAX_EMACS 0
+ 
+ /* This data structure is used to represent a compiled pattern. */
+ 
+ struct re_pattern_buffer
+   {
+     char *buffer;	/* Space holding the compiled pattern commands. */
+     int allocated;	/* Size of space that  buffer  points to */
+     int used;		/* Length of portion of buffer actually occupied */
+     char *fastmap;	/* Pointer to fastmap, if any, or zero if none. */
+ 			/* re_search uses the fastmap, if there is one,
+ 			   to skip quickly over totally implausible characters */
+     char *translate;	/* Translate table to apply to all characters before comparing.
+ 			   Or zero for no translation.
+ 			   The translation is applied to a pattern when it is compiled
+ 			   and to data when it is matched. */
+     char fastmap_accurate;
+ 			/* Set to zero when a new pattern is stored,
+ 			   set to one when the fastmap is updated from it. */
+     char can_be_null;   /* Set to one by compiling fastmap
+ 			   if this pattern might match the null string.
+ 			   It does not necessarily match the null string
+ 			   in that case, but if this is zero, it cannot.
+ 			   2 as value means can match null string
+ 			   but at end of range or before a character
+ 			   listed in the fastmap.  */
+   };
+ 
+ /* Structure to store "register" contents data in.
+ 
+    Pass the address of such a structure as an argument to re_match, etc.,
+    if you want this information back.
+ 
+    start[i] and end[i] record the string matched by \( ... \) grouping i,
+    for i from 1 to RE_NREGS - 1.
+    start[0] and end[0] record the entire string matched. */
+ 
+ struct re_registers
+   {
+     int start[RE_NREGS];
+     int end[RE_NREGS];
+   };
+ 
+ /* These are the command codes that appear in compiled regular expressions, one per byte.
+   Some command codes are followed by argument bytes.
+   A command code can specify any interpretation whatever for its arguments.
+   Zero-bytes may appear in the compiled regular expression. */
+ 
+ enum regexpcode
+   {
+     unused,
+     exactn,    /* followed by one byte giving n, and then by n literal bytes */
+     begline,   /* fails unless at beginning of line */
+     endline,   /* fails unless at end of line */
+     jump,	 /* followed by two bytes giving relative address to jump to */
+     on_failure_jump,	 /* followed by two bytes giving relative address of place
+ 		            to resume at in case of failure. */
+     finalize_jump,	 /* Throw away latest failure point and then jump to address. */
+     maybe_finalize_jump, /* Like jump but finalize if safe to do so.
+ 			    This is used to jump back to the beginning
+ 			    of a repeat.  If the command that follows
+ 			    this jump is clearly incompatible with the
+ 			    one at the beginning of the repeat, such that
+ 			    we can be sure that there is no use backtracking
+ 			    out of repetitions already completed,
+ 			    then we finalize. */
+     dummy_failure_jump,  /* jump, and push a dummy failure point.
+ 			    This failure point will be thrown away
+ 			    if an attempt is made to use it for a failure.
+ 			    A + construct makes this before the first repeat.  */
+     anychar,	 /* matches any one character */
+     charset,     /* matches any one char belonging to specified set.
+ 		    First following byte is # bitmap bytes.
+ 		    Then come bytes for a bit-map saying which chars are in.
+ 		    Bits in each byte are ordered low-bit-first.
+ 		    A character is in the set if its bit is 1.
+ 		    A character too large to have a bit in the map
+ 		    is automatically not in the set */
+     charset_not, /* similar but match any character that is NOT one of those specified */
+     start_memory, /* starts remembering the text that is matched
+ 		    and stores it in a memory register.
+ 		    followed by one byte containing the register number.
+ 		    Register numbers must be in the range 0 through NREGS. */
+     stop_memory, /* stops remembering the text that is matched
+ 		    and stores it in a memory register.
+ 		    followed by one byte containing the register number.
+ 		    Register numbers must be in the range 0 through NREGS. */
+     duplicate,    /* match a duplicate of something remembered.
+ 		    Followed by one byte containing the index of the memory register. */
+     before_dot,	 /* Succeeds if before dot */
+     at_dot,	 /* Succeeds if at dot */
+     after_dot,	 /* Succeeds if after dot */
+     begbuf,      /* Succeeds if at beginning of buffer */
+     endbuf,      /* Succeeds if at end of buffer */
+     wordchar,    /* Matches any word-constituent character */
+     notwordchar, /* Matches any char that is not a word-constituent */
+     wordbeg,	 /* Succeeds if at word beginning */
+     wordend,	 /* Succeeds if at word end */
+     wordbound,   /* Succeeds if at a word boundary */
+     notwordbound, /* Succeeds if not at a word boundary */
+     syntaxspec,  /* Matches any character whose syntax is specified.
+ 		    followed by a byte which contains a syntax code, Sword or such like */
+     notsyntaxspec /* Matches any character whose syntax differs from the specified. */
+   };
+ 
+ extern char *re_compile_pattern ();
+ /* Is this really advertised? */
+ extern void re_compile_fastmap ();
+ extern int re_search (), re_search_2 ();
+ extern int re_match (), re_match_2 ();
+ 
+ /* 4.2 bsd compatibility (yuck) */
+ extern char *re_comp ();
+ extern int re_exec ();
+ 
+ #ifdef SYNTAX_TABLE
+ extern char *re_syntax_table;
+ #endif

Rob
-- 
UUCP:   ...!mcvax!ukc!warwick!cudcv	PHONE:  +44 203 523037
JANET:  cudcv@uk.ac.warwick             ARPA:   cudcv@warwick.ac.uk
Rob McMahon, Computing Services, Warwick University, Coventry CV4 7AL, England