Newsgroups: comp.sources.misc From: karl@sugar.neosoft.com (Karl Lehenbauer) Subject: v25i086: tcl - tool command language, version 6.1, Part18/33 Message-ID: <1991Nov15.224847.20860@sparky.imd.sterling.com> X-Md4-Signature: 20b946d85ebcce76f62a10f231defea4 Date: Fri, 15 Nov 1991 22:48:47 GMT Approved: kent@sparky.imd.sterling.com Submitted-by: karl@sugar.neosoft.com (Karl Lehenbauer) Posting-number: Volume 25, Issue 86 Archive-name: tcl/part18 Environment: UNIX #! /bin/sh # This is a shell archive. Remove anything before this line, then unpack # it by saving it into a file and typing "sh file". To overwrite existing # files, type "sh file -c". You can also feed this as standard input via # unshar, or by typing "sh 'tcl6.1/regexp.c' <<'END_OF_FILE' X/* X * regcomp and regexec -- regsub and regerror are elsewhere X * X * Copyright (c) 1986 by University of Toronto. X * Written by Henry Spencer. Not derived from licensed software. X * X * Permission is granted to anyone to use this software for any X * purpose on any computer system, and to redistribute it freely, X * subject to the following restrictions: X * X * 1. The author is not responsible for the consequences of use of X * this software, no matter how awful, even if they arise X * from defects in it. X * X * 2. The origin of this software must not be misrepresented, either X * by explicit claim or by omission. X * X * 3. Altered versions must be plainly marked as such, and must not X * be misrepresented as being the original software. X * X * Beware that some of this code is subtly aware of the way operator X * precedence is structured in regular expressions. Serious changes in X * regular-expression syntax might require a total rethink. X * X * *** NOTE: this code has been altered slightly for use in Tcl. *** X * *** The only change is to use ckalloc and ckfree instead of *** X * *** malloc and free. *** X */ X#include "tclInt.h" X X/* X * The "internal use only" fields in regexp.h are present to pass info from X * compile to execute that permits the execute phase to run lots faster on X * simple cases. They are: X * X * regstart char that must begin a match; '\0' if none obvious X * reganch is the match anchored (at beginning-of-line only)? X * regmust string (pointer into program) that match must include, or NULL X * regmlen length of regmust string X * X * Regstart and reganch permit very fast decisions on suitable starting points X * for a match, cutting down the work a lot. Regmust permits fast rejection X * of lines that cannot possibly match. The regmust tests are costly enough X * that regcomp() supplies a regmust only if the r.e. contains something X * potentially expensive (at present, the only such thing detected is * or + X * at the start of the r.e., which can involve a lot of backup). Regmlen is X * supplied because the test in regexec() needs it and regcomp() is computing X * it anyway. X */ X X/* X * Structure for regexp "program". This is essentially a linear encoding X * of a nondeterministic finite-state machine (aka syntax charts or X * "railroad normal form" in parsing technology). Each node is an opcode X * plus a "next" pointer, possibly plus an operand. "Next" pointers of X * all nodes except BRANCH implement concatenation; a "next" pointer with X * a BRANCH on both ends of it is connecting two alternatives. (Here we X * have one of the subtle syntax dependencies: an individual BRANCH (as X * opposed to a collection of them) is never concatenated with anything X * because of operator precedence.) The operand of some types of node is X * a literal string; for others, it is a node leading into a sub-FSM. In X * particular, the operand of a BRANCH node is the first node of the branch. X * (NB this is *not* a tree structure: the tail of the branch connects X * to the thing following the set of BRANCHes.) The opcodes are: X */ X X/* definition number opnd? meaning */ X#define END 0 /* no End of program. */ X#define BOL 1 /* no Match "" at beginning of line. */ X#define EOL 2 /* no Match "" at end of line. */ X#define ANY 3 /* no Match any one character. */ X#define ANYOF 4 /* str Match any character in this string. */ X#define ANYBUT 5 /* str Match any character not in this string. */ X#define BRANCH 6 /* node Match this alternative, or the next... */ X#define BACK 7 /* no Match "", "next" ptr points backward. */ X#define EXACTLY 8 /* str Match this string. */ X#define NOTHING 9 /* no Match empty string. */ X#define STAR 10 /* node Match this (simple) thing 0 or more times. */ X#define PLUS 11 /* node Match this (simple) thing 1 or more times. */ X#define OPEN 20 /* no Mark this point in input as start of #n. */ X /* OPEN+1 is number 1, etc. */ X#define CLOSE 30 /* no Analogous to OPEN. */ X X/* X * Opcode notes: X * X * BRANCH The set of branches constituting a single choice are hooked X * together with their "next" pointers, since precedence prevents X * anything being concatenated to any individual branch. The X * "next" pointer of the last BRANCH in a choice points to the X * thing following the whole choice. This is also where the X * final "next" pointer of each individual branch points; each X * branch starts with the operand node of a BRANCH node. X * X * BACK Normal "next" pointers all implicitly point forward; BACK X * exists to make loop structures possible. X * X * STAR,PLUS '?', and complex '*' and '+', are implemented as circular X * BRANCH structures using BACK. Simple cases (one character X * per match) are implemented with STAR and PLUS for speed X * and to minimize recursive plunges. X * X * OPEN,CLOSE ...are numbered at compile time. X */ X X/* X * A node is one char of opcode followed by two chars of "next" pointer. X * "Next" pointers are stored as two 8-bit pieces, high order first. The X * value is a positive offset from the opcode of the node containing it. X * An operand, if any, simply follows the node. (Note that much of the X * code generation knows about this implicit relationship.) X * X * Using two bytes for the "next" pointer is vast overkill for most things, X * but allows patterns to get big without disasters. X */ X#define OP(p) (*(p)) X#define NEXT(p) (((*((p)+1)&0377)<<8) + (*((p)+2)&0377)) X#define OPERAND(p) ((p) + 3) X X/* X * See regmagic.h for one further detail of program structure. X */ X X X/* X * Utility definitions. X */ X#ifndef CHARBITS X#define UCHARAT(p) ((int)*(unsigned char *)(p)) X#else X#define UCHARAT(p) ((int)*(p)&CHARBITS) X#endif X X#define FAIL(m) { regerror(m); return(NULL); } X#define ISMULT(c) ((c) == '*' || (c) == '+' || (c) == '?') X#define META "^$.[()|?+*\\" X X/* X * Flags to be passed up and down. X */ X#define HASWIDTH 01 /* Known never to match null string. */ X#define SIMPLE 02 /* Simple enough to be STAR/PLUS operand. */ X#define SPSTART 04 /* Starts with * or +. */ X#define WORST 0 /* Worst case. */ X X/* X * Global work variables for regcomp(). X */ Xstatic char *regparse; /* Input-scan pointer. */ Xstatic int regnpar; /* () count. */ Xstatic char regdummy; Xstatic char *regcode; /* Code-emit pointer; ®dummy = don't. */ Xstatic long regsize; /* Code size. */ X X/* X * The first byte of the regexp internal "program" is actually this magic X * number; the start node begins in the second byte. X */ X#define MAGIC 0234 X X X/* X * Forward declarations for regcomp()'s friends. X */ X#ifndef STATIC X#define STATIC static X#endif XSTATIC char *reg(); XSTATIC char *regbranch(); XSTATIC char *regpiece(); XSTATIC char *regatom(); XSTATIC char *regnode(); XSTATIC char *regnext(); XSTATIC void regc(); XSTATIC void reginsert(); XSTATIC void regtail(); XSTATIC void regoptail(); X#ifdef STRCSPN XSTATIC int strcspn(); X#endif X X/* X - regcomp - compile a regular expression into internal code X * X * We can't allocate space until we know how big the compiled form will be, X * but we can't compile it (and thus know how big it is) until we've got a X * place to put the code. So we cheat: we compile it twice, once with code X * generation turned off and size counting turned on, and once "for real". X * This also means that we don't allocate space until we are sure that the X * thing really will compile successfully, and we never have to move the X * code and thus invalidate pointers into it. (Note that it has to be in X * one piece because free() must be able to free it all.) X * X * Beware that the optimization-preparation code in here knows about some X * of the structure of the compiled regexp. X */ Xregexp * Xregcomp(exp) Xchar *exp; X{ X register regexp *r; X register char *scan; X register char *longest; X register int len; X int flags; X X if (exp == NULL) X FAIL("NULL argument"); X X /* First pass: determine size, legality. */ X regparse = exp; X regnpar = 1; X regsize = 0L; X regcode = ®dummy; X regc(MAGIC); X if (reg(0, &flags) == NULL) X return(NULL); X X /* Small enough for pointer-storage convention? */ X if (regsize >= 32767L) /* Probably could be 65535L. */ X FAIL("regexp too big"); X X /* Allocate space. */ X r = (regexp *)ckalloc(sizeof(regexp) + (unsigned)regsize); X if (r == NULL) X FAIL("out of space"); X X /* Second pass: emit code. */ X regparse = exp; X regnpar = 1; X regcode = r->program; X regc(MAGIC); X if (reg(0, &flags) == NULL) X return(NULL); X X /* Dig out information for optimizations. */ X r->regstart = '\0'; /* Worst-case defaults. */ X r->reganch = 0; X r->regmust = NULL; X r->regmlen = 0; X scan = r->program+1; /* First BRANCH. */ X if (OP(regnext(scan)) == END) { /* Only one top-level choice. */ X scan = OPERAND(scan); X X /* Starting-point info. */ X if (OP(scan) == EXACTLY) X r->regstart = *OPERAND(scan); X else if (OP(scan) == BOL) X r->reganch++; X X /* X * If there's something expensive in the r.e., find the X * longest literal string that must appear and make it the X * regmust. Resolve ties in favor of later strings, since X * the regstart check works with the beginning of the r.e. X * and avoiding duplication strengthens checking. Not a X * strong reason, but sufficient in the absence of others. X */ X if (flags&SPSTART) { X longest = NULL; X len = 0; X for (; scan != NULL; scan = regnext(scan)) X if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) { X longest = OPERAND(scan); X len = strlen(OPERAND(scan)); X } X r->regmust = longest; X r->regmlen = len; X } X } X X return(r); X} X X/* X - reg - regular expression, i.e. main body or parenthesized thing X * X * Caller must absorb opening parenthesis. X * X * Combining parenthesis handling with the base level of regular expression X * is a trifle forced, but the need to tie the tails of the branches to what X * follows makes it hard to avoid. X */ Xstatic char * Xreg(paren, flagp) Xint paren; /* Parenthesized? */ Xint *flagp; X{ X register char *ret; X register char *br; X register char *ender; X register int parno = 0; X int flags; X X *flagp = HASWIDTH; /* Tentatively. */ X X /* Make an OPEN node, if parenthesized. */ X if (paren) { X if (regnpar >= NSUBEXP) X FAIL("too many ()"); X parno = regnpar; X regnpar++; X ret = regnode(OPEN+parno); X } else X ret = NULL; X X /* Pick up the branches, linking them together. */ X br = regbranch(&flags); X if (br == NULL) X return(NULL); X if (ret != NULL) X regtail(ret, br); /* OPEN -> first. */ X else X ret = br; X if (!(flags&HASWIDTH)) X *flagp &= ~HASWIDTH; X *flagp |= flags&SPSTART; X while (*regparse == '|') { X regparse++; X br = regbranch(&flags); X if (br == NULL) X return(NULL); X regtail(ret, br); /* BRANCH -> BRANCH. */ X if (!(flags&HASWIDTH)) X *flagp &= ~HASWIDTH; X *flagp |= flags&SPSTART; X } X X /* Make a closing node, and hook it on the end. */ X ender = regnode((paren) ? CLOSE+parno : END); X regtail(ret, ender); X X /* Hook the tails of the branches to the closing node. */ X for (br = ret; br != NULL; br = regnext(br)) X regoptail(br, ender); X X /* Check for proper termination. */ X if (paren && *regparse++ != ')') { X FAIL("unmatched ()"); X } else if (!paren && *regparse != '\0') { X if (*regparse == ')') { X FAIL("unmatched ()"); X } else X FAIL("junk on end"); /* "Can't happen". */ X /* NOTREACHED */ X } X X return(ret); X} X X/* X - regbranch - one alternative of an | operator X * X * Implements the concatenation operator. X */ Xstatic char * Xregbranch(flagp) Xint *flagp; X{ X register char *ret; X register char *chain; X register char *latest; X int flags; X X *flagp = WORST; /* Tentatively. */ X X ret = regnode(BRANCH); X chain = NULL; X while (*regparse != '\0' && *regparse != '|' && *regparse != ')') { X latest = regpiece(&flags); X if (latest == NULL) X return(NULL); X *flagp |= flags&HASWIDTH; X if (chain == NULL) /* First piece. */ X *flagp |= flags&SPSTART; X else X regtail(chain, latest); X chain = latest; X } X if (chain == NULL) /* Loop ran zero times. */ X (void) regnode(NOTHING); X X return(ret); X} X X/* X - regpiece - something followed by possible [*+?] X * X * Note that the branching code sequences used for ? and the general cases X * of * and + are somewhat optimized: they use the same NOTHING node as X * both the endmarker for their branch list and the body of the last branch. X * It might seem that this node could be dispensed with entirely, but the X * endmarker role is not redundant. X */ Xstatic char * Xregpiece(flagp) Xint *flagp; X{ X register char *ret; X register char op; X register char *next; X int flags; X X ret = regatom(&flags); X if (ret == NULL) X return(NULL); X X op = *regparse; X if (!ISMULT(op)) { X *flagp = flags; X return(ret); X } X X if (!(flags&HASWIDTH) && op != '?') X FAIL("*+ operand could be empty"); X *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH); X X if (op == '*' && (flags&SIMPLE)) X reginsert(STAR, ret); X else if (op == '*') { X /* Emit x* as (x&|), where & means "self". */ X reginsert(BRANCH, ret); /* Either x */ X regoptail(ret, regnode(BACK)); /* and loop */ X regoptail(ret, ret); /* back */ X regtail(ret, regnode(BRANCH)); /* or */ X regtail(ret, regnode(NOTHING)); /* null. */ X } else if (op == '+' && (flags&SIMPLE)) X reginsert(PLUS, ret); X else if (op == '+') { X /* Emit x+ as x(&|), where & means "self". */ X next = regnode(BRANCH); /* Either */ X regtail(ret, next); X regtail(regnode(BACK), ret); /* loop back */ X regtail(next, regnode(BRANCH)); /* or */ X regtail(ret, regnode(NOTHING)); /* null. */ X } else if (op == '?') { X /* Emit x? as (x|) */ X reginsert(BRANCH, ret); /* Either x */ X regtail(ret, regnode(BRANCH)); /* or */ X next = regnode(NOTHING); /* null. */ X regtail(ret, next); X regoptail(ret, next); X } X regparse++; X if (ISMULT(*regparse)) X FAIL("nested *?+"); X X return(ret); X} X X/* X - regatom - the lowest level X * X * Optimization: gobbles an entire sequence of ordinary characters so that X * it can turn them into a single node, which is smaller to store and X * faster to run. Backslashed characters are exceptions, each becoming a X * separate node; the code is simpler that way and it's not worth fixing. X */ Xstatic char * Xregatom(flagp) Xint *flagp; X{ X register char *ret; X int flags; X X *flagp = WORST; /* Tentatively. */ X X switch (*regparse++) { X case '^': X ret = regnode(BOL); X break; X case '$': X ret = regnode(EOL); X break; X case '.': X ret = regnode(ANY); X *flagp |= HASWIDTH|SIMPLE; X break; X case '[': { X register int clss; X register int classend; X X if (*regparse == '^') { /* Complement of range. */ X ret = regnode(ANYBUT); X regparse++; X } else X ret = regnode(ANYOF); X if (*regparse == ']' || *regparse == '-') X regc(*regparse++); X while (*regparse != '\0' && *regparse != ']') { X if (*regparse == '-') { X regparse++; X if (*regparse == ']' || *regparse == '\0') X regc('-'); X else { X clss = UCHARAT(regparse-2)+1; X classend = UCHARAT(regparse); X if (clss > classend+1) X FAIL("invalid [] range"); X for (; clss <= classend; clss++) X regc(clss); X regparse++; X } X } else X regc(*regparse++); X } X regc('\0'); X if (*regparse != ']') X FAIL("unmatched []"); X regparse++; X *flagp |= HASWIDTH|SIMPLE; X } X break; X case '(': X ret = reg(1, &flags); X if (ret == NULL) X return(NULL); X *flagp |= flags&(HASWIDTH|SPSTART); X break; X case '\0': X case '|': X case ')': X FAIL("internal urp"); /* Supposed to be caught earlier. */ X /* NOTREACHED */ X break; X case '?': X case '+': X case '*': X FAIL("?+* follows nothing"); X /* NOTREACHED */ X break; X case '\\': X if (*regparse == '\0') X FAIL("trailing \\"); X ret = regnode(EXACTLY); X regc(*regparse++); X regc('\0'); X *flagp |= HASWIDTH|SIMPLE; X break; X default: { X register int len; X register char ender; X X regparse--; X len = strcspn(regparse, META); X if (len <= 0) X FAIL("internal disaster"); X ender = *(regparse+len); X if (len > 1 && ISMULT(ender)) X len--; /* Back off clear of ?+* operand. */ X *flagp |= HASWIDTH; X if (len == 1) X *flagp |= SIMPLE; X ret = regnode(EXACTLY); X while (len > 0) { X regc(*regparse++); X len--; X } X regc('\0'); X } X break; X } X X return(ret); X} X X/* X - regnode - emit a node X */ Xstatic char * /* Location. */ Xregnode(op) Xchar op; X{ X register char *ret; X register char *ptr; X X ret = regcode; X if (ret == ®dummy) { X regsize += 3; X return(ret); X } X X ptr = ret; X *ptr++ = op; X *ptr++ = '\0'; /* Null "next" pointer. */ X *ptr++ = '\0'; X regcode = ptr; X X return(ret); X} X X/* X - regc - emit (if appropriate) a byte of code X */ Xstatic void Xregc(b) Xchar b; X{ X if (regcode != ®dummy) X *regcode++ = b; X else X regsize++; X} X X/* X - reginsert - insert an operator in front of already-emitted operand X * X * Means relocating the operand. X */ Xstatic void Xreginsert(op, opnd) Xchar op; Xchar *opnd; X{ X register char *src; X register char *dst; X register char *place; X X if (regcode == ®dummy) { X regsize += 3; X return; X } X X src = regcode; X regcode += 3; X dst = regcode; X while (src > opnd) X *--dst = *--src; X X place = opnd; /* Op node, where operand used to be. */ X *place++ = op; X *place++ = '\0'; X *place++ = '\0'; X} X X/* X - regtail - set the next-pointer at the end of a node chain X */ Xstatic void Xregtail(p, val) Xchar *p; Xchar *val; X{ X register char *scan; X register char *temp; X register int offset; X X if (p == ®dummy) X return; X X /* Find last node. */ X scan = p; X for (;;) { X temp = regnext(scan); X if (temp == NULL) X break; X scan = temp; X } X X if (OP(scan) == BACK) X offset = scan - val; X else X offset = val - scan; X *(scan+1) = (offset>>8)&0377; X *(scan+2) = offset&0377; X} X X/* X - regoptail - regtail on operand of first argument; nop if operandless X */ Xstatic void Xregoptail(p, val) Xchar *p; Xchar *val; X{ X /* "Operandless" and "op != BRANCH" are synonymous in practice. */ X if (p == NULL || p == ®dummy || OP(p) != BRANCH) X return; X regtail(OPERAND(p), val); X} X X/* X * regexec and friends X */ X X/* X * Global work variables for regexec(). X */ Xstatic char *reginput; /* String-input pointer. */ Xstatic char *regbol; /* Beginning of input, for ^ check. */ Xstatic char **regstartp; /* Pointer to startp array. */ Xstatic char **regendp; /* Ditto for endp. */ X X/* X * Forwards. X */ XSTATIC int regtry(); XSTATIC int regmatch(); XSTATIC int regrepeat(); X X#ifdef DEBUG Xint regnarrate = 0; Xvoid regdump(); XSTATIC char *regprop(); X#endif X X/* X - regexec - match a regexp against a string X */ Xint Xregexec(prog, string) Xregister regexp *prog; Xregister char *string; X{ X register char *s; X extern char *strchr(); X X /* Be paranoid... */ X if (prog == NULL || string == NULL) { X regerror("NULL parameter"); X return(0); X } X X /* Check validity of program. */ X if (UCHARAT(prog->program) != MAGIC) { X regerror("corrupted program"); X return(0); X } X X /* If there is a "must appear" string, look for it. */ X if (prog->regmust != NULL) { X s = string; X while ((s = strchr(s, prog->regmust[0])) != NULL) { X if (strncmp(s, prog->regmust, prog->regmlen) == 0) X break; /* Found it. */ X s++; X } X if (s == NULL) /* Not present. */ X return(0); X } X X /* Mark beginning of line for ^ . */ X regbol = string; X X /* Simplest case: anchored match need be tried only once. */ X if (prog->reganch) X return(regtry(prog, string)); X X /* Messy cases: unanchored match. */ X s = string; X if (prog->regstart != '\0') X /* We know what char it must start with. */ X while ((s = strchr(s, prog->regstart)) != NULL) { X if (regtry(prog, s)) X return(1); X s++; X } X else X /* We don't -- general case. */ X do { X if (regtry(prog, s)) X return(1); X } while (*s++ != '\0'); X X /* Failure. */ X return(0); X} X X/* X - regtry - try match at specific point X */ Xstatic int /* 0 failure, 1 success */ Xregtry(prog, string) Xregexp *prog; Xchar *string; X{ X register int i; X register char **sp; X register char **ep; X X reginput = string; X regstartp = prog->startp; X regendp = prog->endp; X X sp = prog->startp; X ep = prog->endp; X for (i = NSUBEXP; i > 0; i--) { X *sp++ = NULL; X *ep++ = NULL; X } X if (regmatch(prog->program + 1)) { X prog->startp[0] = string; X prog->endp[0] = reginput; X return(1); X } else X return(0); X} X X/* X - regmatch - main matching routine X * X * Conceptually the strategy is simple: check to see whether the current X * node matches, call self recursively to see whether the rest matches, X * and then act accordingly. In practice we make some effort to avoid X * recursion, in particular by going through "ordinary" nodes (that don't X * need to know whether the rest of the match failed) by a loop instead of X * by recursion. X */ Xstatic int /* 0 failure, 1 success */ Xregmatch(prog) Xchar *prog; X{ X register char *scan; /* Current node. */ X char *next; /* Next node. */ X extern char *strchr(); X X scan = prog; X#ifdef DEBUG X if (scan != NULL && regnarrate) X fprintf(stderr, "%s(\n", regprop(scan)); X#endif X while (scan != NULL) { X#ifdef DEBUG X if (regnarrate) X fprintf(stderr, "%s...\n", regprop(scan)); X#endif X next = regnext(scan); X X switch (OP(scan)) { X case BOL: X if (reginput != regbol) X return(0); X break; X case EOL: X if (*reginput != '\0') X return(0); X break; X case ANY: X if (*reginput == '\0') X return(0); X reginput++; X break; X case EXACTLY: { X register int len; X register char *opnd; X X opnd = OPERAND(scan); X /* Inline the first character, for speed. */ X if (*opnd != *reginput) X return(0); X len = strlen(opnd); X if (len > 1 && strncmp(opnd, reginput, len) != 0) X return(0); X reginput += len; X } X break; X case ANYOF: X if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL) X return(0); X reginput++; X break; X case ANYBUT: X if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL) X return(0); X reginput++; X break; X case NOTHING: X break; X case BACK: X break; X case OPEN+1: X case OPEN+2: X case OPEN+3: X case OPEN+4: X case OPEN+5: X case OPEN+6: X case OPEN+7: X case OPEN+8: X case OPEN+9: { X register int no; X register char *save; X X no = OP(scan) - OPEN; X save = reginput; X X if (regmatch(next)) { X /* X * Don't set startp if some later X * invocation of the same parentheses X * already has. X */ X if (regstartp[no] == NULL) X regstartp[no] = save; X return(1); X } else X return(0); X } X /* NOTREACHED */ X break; X case CLOSE+1: X case CLOSE+2: X case CLOSE+3: X case CLOSE+4: X case CLOSE+5: X case CLOSE+6: X case CLOSE+7: X case CLOSE+8: X case CLOSE+9: { X register int no; X register char *save; X X no = OP(scan) - CLOSE; X save = reginput; X X if (regmatch(next)) { X /* X * Don't set endp if some later X * invocation of the same parentheses X * already has. X */ X if (regendp[no] == NULL) X regendp[no] = save; X return(1); X } else X return(0); X } X /* NOTREACHED */ X break; X case BRANCH: { X register char *save; X X if (OP(next) != BRANCH) /* No choice. */ X next = OPERAND(scan); /* Avoid recursion. */ X else { X do { X save = reginput; X if (regmatch(OPERAND(scan))) X return(1); X reginput = save; X scan = regnext(scan); X } while (scan != NULL && OP(scan) == BRANCH); X return(0); X /* NOTREACHED */ X } X } X /* NOTREACHED */ X break; X case STAR: X case PLUS: { X register char nextch; X register int no; X register char *save; X register int min; X X /* X * Lookahead to avoid useless match attempts X * when we know what character comes next. X */ X nextch = '\0'; X if (OP(next) == EXACTLY) X nextch = *OPERAND(next); X min = (OP(scan) == STAR) ? 0 : 1; X save = reginput; X no = regrepeat(OPERAND(scan)); X while (no >= min) { X /* If it could work, try it. */ X if (nextch == '\0' || *reginput == nextch) X if (regmatch(next)) X return(1); X /* Couldn't or didn't -- back up. */ X no--; X reginput = save + no; X } X return(0); X } X /* NOTREACHED */ X break; X case END: X return(1); /* Success! */ X /* NOTREACHED */ X break; X default: X regerror("memory corruption"); X return(0); X /* NOTREACHED */ X break; X } X X scan = next; X } X X /* X * We get here only if there's trouble -- normally "case END" is X * the terminating point. X */ X regerror("corrupted pointers"); X return(0); X} X X/* X - regrepeat - repeatedly match something simple, report how many X */ Xstatic int Xregrepeat(p) Xchar *p; X{ X register int count = 0; X register char *scan; X register char *opnd; X X scan = reginput; X opnd = OPERAND(p); X switch (OP(p)) { X case ANY: X count = strlen(scan); X scan += count; X break; X case EXACTLY: X while (*opnd == *scan) { X count++; X scan++; X } X break; X case ANYOF: X while (*scan != '\0' && strchr(opnd, *scan) != NULL) { X count++; X scan++; X } X break; X case ANYBUT: X while (*scan != '\0' && strchr(opnd, *scan) == NULL) { X count++; X scan++; X } X break; X default: /* Oh dear. Called inappropriately. */ X regerror("internal foulup"); X count = 0; /* Best compromise. */ X break; X } X reginput = scan; X X return(count); X} X X/* X - regnext - dig the "next" pointer out of a node X */ Xstatic char * Xregnext(p) Xregister char *p; X{ X register int offset; X X if (p == ®dummy) X return(NULL); X X offset = NEXT(p); X if (offset == 0) X return(NULL); X X if (OP(p) == BACK) X return(p-offset); X else X return(p+offset); X} X X#ifdef DEBUG X XSTATIC char *regprop(); X X/* X - regdump - dump a regexp onto stdout in vaguely comprehensible form X */ Xvoid Xregdump(r) Xregexp *r; X{ X register char *s; X register char op = EXACTLY; /* Arbitrary non-END op. */ X register char *next; X extern char *strchr(); X X X s = r->program + 1; X while (op != END) { /* While that wasn't END last time... */ X op = OP(s); X printf("%2d%s", s-r->program, regprop(s)); /* Where, what. */ X next = regnext(s); X if (next == NULL) /* Next ptr. */ X printf("(0)"); X else X printf("(%d)", (s-r->program)+(next-s)); X s += 3; X if (op == ANYOF || op == ANYBUT || op == EXACTLY) { X /* Literal string, where present. */ X while (*s != '\0') { X putchar(*s); X s++; X } X s++; X } X putchar('\n'); X } X X /* Header fields of interest. */ X if (r->regstart != '\0') X printf("start `%c' ", r->regstart); X if (r->reganch) X printf("anchored "); X if (r->regmust != NULL) X printf("must have \"%s\"", r->regmust); X printf("\n"); X} X X/* X - regprop - printable representation of opcode X */ Xstatic char * Xregprop(op) Xchar *op; X{ X register char *p; X static char buf[50]; X X (void) strcpy(buf, ":"); X X switch (OP(op)) { X case BOL: X p = "BOL"; X break; X case EOL: X p = "EOL"; X break; X case ANY: X p = "ANY"; X break; X case ANYOF: X p = "ANYOF"; X break; X case ANYBUT: X p = "ANYBUT"; X break; X case BRANCH: X p = "BRANCH"; X break; X case EXACTLY: X p = "EXACTLY"; X break; X case NOTHING: X p = "NOTHING"; X break; X case BACK: X p = "BACK"; X break; X case END: X p = "END"; X break; X case OPEN+1: X case OPEN+2: X case OPEN+3: X case OPEN+4: X case OPEN+5: X case OPEN+6: X case OPEN+7: X case OPEN+8: X case OPEN+9: X sprintf(buf+strlen(buf), "OPEN%d", OP(op)-OPEN); X p = NULL; X break; X case CLOSE+1: X case CLOSE+2: X case CLOSE+3: X case CLOSE+4: X case CLOSE+5: X case CLOSE+6: X case CLOSE+7: X case CLOSE+8: X case CLOSE+9: X sprintf(buf+strlen(buf), "CLOSE%d", OP(op)-CLOSE); X p = NULL; X break; X case STAR: X p = "STAR"; X break; X case PLUS: X p = "PLUS"; X break; X default: X regerror("corrupted opcode"); X break; X } X if (p != NULL) X (void) strcat(buf, p); X return(buf); X} X#endif X X/* X * The following is provided for those people who do not have strcspn() in X * their C libraries. They should get off their butts and do something X * about it; at least one public-domain implementation of those (highly X * useful) string routines has been published on Usenet. X */ X#ifdef STRCSPN X/* X * strcspn - find length of initial segment of s1 consisting entirely X * of characters not from s2 X */ X Xstatic int Xstrcspn(s1, s2) Xchar *s1; Xchar *s2; X{ X register char *scan1; X register char *scan2; X register int count; X X count = 0; X for (scan1 = s1; *scan1 != '\0'; scan1++) { X for (scan2 = s2; *scan2 != '\0';) /* ++ moved down. */ X if (*scan1 == *scan2++) X return(count); X count++; X } X return(count); X} X#endif END_OF_FILE if test 28040 -ne `wc -c <'tcl6.1/regexp.c'`; then echo shar: \"'tcl6.1/regexp.c'\" unpacked with wrong size! fi # end of 'tcl6.1/regexp.c' fi echo shar: End of archive 18 \(of 33\). cp /dev/null ark18isdone MISSING="" for I in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 ; do if test ! -f ark${I}isdone ; then MISSING="${MISSING} ${I}" fi done if test "${MISSING}" = "" ; then echo You have unpacked all 33 archives. rm -f ark[1-9]isdone ark[1-9][0-9]isdone else echo You still need to unpack the following archives: echo " " ${MISSING} fi ## End of shell archive. exit 0 exit 0 # Just in case... -- Kent Landfield INTERNET: kent@sparky.IMD.Sterling.COM Sterling Software, IMD UUCP: uunet!sparky!kent Phone: (402) 291-8300 FAX: (402) 291-4362 Please send comp.sources.misc-related mail to kent@uunet.uu.net.