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Modify xalloc so that it also takes err(3)-like arguments.
Write an xrealloc wrapper that works the same way, and use it as well.

People who feel like it may want to add more explicit error messages to
all the places m4 can fail allocating memory...

okay tedu@

/*	$OpenBSD: eval.c,v 1.51 2003/11/17 17:12:10 espie Exp $	*/
/*	$NetBSD: eval.c,v 1.7 1996/11/10 21:21:29 pk Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ozan Yigit at York University.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
#if 0
static char sccsid[] = "@(#)eval.c	8.2 (Berkeley) 4/27/95";
#else
static char rcsid[] = "$OpenBSD: eval.c,v 1.51 2003/11/17 17:12:10 espie Exp $";
#endif
#endif /* not lint */

/*
 * eval.c
 * Facility: m4 macro processor
 * by: oz
 */

#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <fcntl.h>
#include <err.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"
#include "pathnames.h"

static void	dodefn(const char *);
static void	dopushdef(const char *, const char *);
static void	dodump(const char *[], int);
static void	dotrace(const char *[], int, int);
static void	doifelse(const char *[], int);
static int	doincl(const char *);
static int	dopaste(const char *);
static void	gnu_dochq(const char *[], int);
static void	dochq(const char *[], int);
static void	gnu_dochc(const char *[], int);
static void	dochc(const char *[], int);
static void	dodiv(int);
static void	doundiv(const char *[], int);
static void	dosub(const char *[], int);
static void	map(char *, const char *, const char *, const char *);
static const char *handledash(char *, char *, const char *);
static void	expand_builtin(const char *[], int, int);
static void	expand_macro(const char *[], int);
static void	dump_one_def(const char *, struct macro_definition *);

unsigned long	expansion_id;

/*
 * eval - eval all macros and builtins calls
 *	  argc - number of elements in argv.
 *	  argv - element vector :
 *			argv[0] = definition of a user
 *				  macro or NULL if built-in.
 *			argv[1] = name of the macro or
 *				  built-in.
 *			argv[2] = parameters to user-defined
 *			   .	  macro or built-in.
 *			   .
 *
 * A call in the form of macro-or-builtin() will result in:
 *			argv[0] = nullstr
 *			argv[1] = macro-or-builtin
 *			argv[2] = nullstr
 *
 * argc is 3 for macro-or-builtin() and 2 for macro-or-builtin
 */
void
eval(const char *argv[], int argc, int td, int is_traced)
{
	ssize_t mark = -1;

	expansion_id++;
	if (td & RECDEF) 
		errx(1, "%s at line %lu: expanding recursive definition for %s",
			CURRENT_NAME, CURRENT_LINE, argv[1]);
	if (is_traced)
		mark = trace(argv, argc, infile+ilevel);
	if (td == MACRTYPE)
		expand_macro(argv, argc);
	else
		expand_builtin(argv, argc, td);
    	if (mark != -1)
		finish_trace(mark);
}

/*
 * expand_builtin - evaluate built-in macros.
 */
void
expand_builtin(const char *argv[], int argc, int td)
{
	int c, n;
	int ac;
	static int sysval = 0;

#ifdef DEBUG
	printf("argc = %d\n", argc);
	for (n = 0; n < argc; n++)
		printf("argv[%d] = %s\n", n, argv[n]);
	fflush(stdout);
#endif

 /*
  * if argc == 3 and argv[2] is null, then we
  * have macro-or-builtin() type call. We adjust
  * argc to avoid further checking..
  */
  	ac = argc;

	if (argc == 3 && !*(argv[2]))
		argc--;

	switch (td & TYPEMASK) {

	case DEFITYPE:
		if (argc > 2)
			dodefine(argv[2], (argc > 3) ? argv[3] : null);
		break;

	case PUSDTYPE:
		if (argc > 2)
			dopushdef(argv[2], (argc > 3) ? argv[3] : null);
		break;

	case DUMPTYPE:
		dodump(argv, argc);
		break;

	case TRACEONTYPE:
		dotrace(argv, argc, 1);
		break;

	case TRACEOFFTYPE:
		dotrace(argv, argc, 0);
		break;

	case EXPRTYPE:
	/*
	 * doexpr - evaluate arithmetic
	 * expression
	 */
		if (argc > 2)
			pbnum(expr(argv[2]));
		break;

	case IFELTYPE:
		if (argc > 4)
			doifelse(argv, argc);
		break;

	case IFDFTYPE:
	/*
	 * doifdef - select one of two
	 * alternatives based on the existence of
	 * another definition
	 */
		if (argc > 3) {
			if (lookup_macro_definition(argv[2]) != NULL)
				pbstr(argv[3]);
			else if (argc > 4)
				pbstr(argv[4]);
		}
		break;

	case LENGTYPE:
	/*
	 * dolen - find the length of the
	 * argument
	 */
		pbnum((argc > 2) ? strlen(argv[2]) : 0);
		break;

	case INCRTYPE:
	/*
	 * doincr - increment the value of the
	 * argument
	 */
		if (argc > 2)
			pbnum(atoi(argv[2]) + 1);
		break;

	case DECRTYPE:
	/*
	 * dodecr - decrement the value of the
	 * argument
	 */
		if (argc > 2)
			pbnum(atoi(argv[2]) - 1);
		break;

	case SYSCTYPE:
	/*
	 * dosys - execute system command
	 */
		if (argc > 2)
			sysval = system(argv[2]);
		break;

	case SYSVTYPE:
	/*
	 * dosysval - return value of the last
	 * system call.
	 * 
	 */
		pbnum(sysval);
		break;

	case ESYSCMDTYPE:
		if (argc > 2)
			doesyscmd(argv[2]);
	    	break;
	case INCLTYPE:
		if (argc > 2)
			if (!doincl(argv[2]))
				err(1, "%s at line %lu: include(%s)",
				    CURRENT_NAME, CURRENT_LINE, argv[2]);
		break;

	case SINCTYPE:
		if (argc > 2)
			(void) doincl(argv[2]);
		break;
#ifdef EXTENDED
	case PASTTYPE:
		if (argc > 2)
			if (!dopaste(argv[2]))
				err(1, "%s at line %lu: paste(%s)", 
				    CURRENT_NAME, CURRENT_LINE, argv[2]);
		break;

	case SPASTYPE:
		if (argc > 2)
			(void) dopaste(argv[2]);
		break;
#endif
	case CHNQTYPE:
		if (mimic_gnu)
			gnu_dochq(argv, ac);
		else
			dochq(argv, argc);
		break;

	case CHNCTYPE:
		if (mimic_gnu)
			gnu_dochc(argv, ac);
		else
			dochc(argv, argc);
		break;

	case SUBSTYPE:
	/*
	 * dosub - select substring
	 * 
	 */
		if (argc > 3)
			dosub(argv, argc);
		break;

	case SHIFTYPE:
	/*
	 * doshift - push back all arguments
	 * except the first one (i.e. skip
	 * argv[2])
	 */
		if (argc > 3) {
			for (n = argc - 1; n > 3; n--) {
				pbstr(rquote);
				pbstr(argv[n]);
				pbstr(lquote);
				putback(COMMA);
			}
			pbstr(rquote);
			pbstr(argv[3]);
			pbstr(lquote);
		}
		break;

	case DIVRTYPE:
		if (argc > 2 && (n = atoi(argv[2])) != 0)
			dodiv(n);
		else {
			active = stdout;
			oindex = 0;
		}
		break;

	case UNDVTYPE:
		doundiv(argv, argc);
		break;

	case DIVNTYPE:
	/*
	 * dodivnum - return the number of
	 * current output diversion
	 */
		pbnum(oindex);
		break;

	case UNDFTYPE:
	/*
	 * doundefine - undefine a previously
	 * defined macro(s) or m4 keyword(s).
	 */
		if (argc > 2)
			for (n = 2; n < argc; n++)
				macro_undefine(argv[n]);
		break;

	case POPDTYPE:
	/*
	 * dopopdef - remove the topmost
	 * definitions of macro(s) or m4
	 * keyword(s).
	 */
		if (argc > 2)
			for (n = 2; n < argc; n++)
				macro_popdef(argv[n]);
		break;

	case MKTMTYPE:
	/*
	 * dotemp - create a temporary file
	 */
		if (argc > 2) {
			int fd;
			char *temp;

			temp = xstrdup(argv[2]);
			
			fd = mkstemp(temp);
			if (fd == -1)
				err(1, 
	    "%s at line %lu: couldn't make temp file %s", 
	    CURRENT_NAME, CURRENT_LINE, argv[2]);
			close(fd);
			pbstr(temp);
			free(temp);
		}
		break;

	case TRNLTYPE:
	/*
	 * dotranslit - replace all characters in
	 * the source string that appears in the
	 * "from" string with the corresponding
	 * characters in the "to" string.
	 */
		if (argc > 3) {
			char *temp;

			temp = xalloc(strlen(argv[2])+1, NULL);
			if (argc > 4)
				map(temp, argv[2], argv[3], argv[4]);
			else
				map(temp, argv[2], argv[3], null);
			pbstr(temp);
			free(temp);
		} else if (argc > 2)
			pbstr(argv[2]);
		break;

	case INDXTYPE:
	/*
	 * doindex - find the index of the second
	 * argument string in the first argument
	 * string. -1 if not present.
	 */
		pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
		break;

	case ERRPTYPE:
	/*
	 * doerrp - print the arguments to stderr
	 * file
	 */
		if (argc > 2) {
			for (n = 2; n < argc; n++)
				fprintf(stderr, "%s ", argv[n]);
			fprintf(stderr, "\n");
		}
		break;

	case DNLNTYPE:
	/*
	 * dodnl - eat-up-to and including
	 * newline
	 */
		while ((c = gpbc()) != '\n' && c != EOF)
			;
		break;

	case M4WRTYPE:
	/*
	 * dom4wrap - set up for
	 * wrap-up/wind-down activity
	 */
		m4wraps = (argc > 2) ? xstrdup(argv[2]) : null;
		break;

	case EXITTYPE:
	/*
	 * doexit - immediate exit from m4.
	 */
		killdiv();
		exit((argc > 2) ? atoi(argv[2]) : 0);
		break;

	case DEFNTYPE:
		if (argc > 2)
			for (n = 2; n < argc; n++)
				dodefn(argv[n]);
		break;

	case INDIRTYPE:	/* Indirect call */
		if (argc > 2)
			doindir(argv, argc);
		break;
	
	case BUILTINTYPE: /* Builtins only */
		if (argc > 2)
			dobuiltin(argv, argc);
		break;

	case PATSTYPE:
		if (argc > 2)
			dopatsubst(argv, argc);
		break;
	case REGEXPTYPE:
		if (argc > 2)
			doregexp(argv, argc);
		break;
	case LINETYPE:
		doprintlineno(infile+ilevel);
		break;
	case FILENAMETYPE:
		doprintfilename(infile+ilevel);
		break;
	case SELFTYPE:
		pbstr(rquote);
		pbstr(argv[1]);
		pbstr(lquote);
		break;
	default:
		errx(1, "%s at line %lu: eval: major botch.",
			CURRENT_NAME, CURRENT_LINE);
		break;
	}
}

/*
 * expand_macro - user-defined macro expansion
 */
void
expand_macro(const char *argv[], int argc)
{
	const char *t;
	const char *p;
	int n;
	int argno;

	t = argv[0];		       /* defn string as a whole */
	p = t;
	while (*p)
		p++;
	p--;			       /* last character of defn */
	while (p > t) {
		if (*(p - 1) != ARGFLAG)
			PUTBACK(*p);
		else {
			switch (*p) {

			case '#':
				pbnum(argc - 2);
				break;
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
				if ((argno = *p - '0') < argc - 1)
					pbstr(argv[argno + 1]);
				break;
			case '*':
				if (argc > 2) {
					for (n = argc - 1; n > 2; n--) {
						pbstr(argv[n]);
						putback(COMMA);
					}
					pbstr(argv[2]);
			    	}
				break;
                        case '@':
				if (argc > 2) {
					for (n = argc - 1; n > 2; n--) {
						pbstr(rquote);
						pbstr(argv[n]);
						pbstr(lquote);
						putback(COMMA);
					}
					pbstr(rquote);
					pbstr(argv[2]);
					pbstr(lquote);
				}
                                break;
			default:
				PUTBACK(*p);
				PUTBACK('$');
				break;
			}
			p--;
		}
		p--;
	}
	if (p == t)		       /* do last character */
		PUTBACK(*p);
}


/*
 * dodefine - install definition in the table
 */
void
dodefine(const char *name, const char *defn)
{
	if (!*name)
		errx(1, "%s at line %lu: null definition.", CURRENT_NAME,
		    CURRENT_LINE);
	macro_define(name, defn);
}

/*
 * dodefn - push back a quoted definition of
 *      the given name.
 */
static void
dodefn(const char *name)
{
	struct macro_definition *p;
	char *real;

	if ((p = lookup_macro_definition(name)) != NULL) {
		if ((p->type & TYPEMASK) == MACRTYPE) {
			pbstr(rquote);
			pbstr(p->defn);
			pbstr(lquote);
		} else {
			pbstr(p->defn);
			pbstr(BUILTIN_MARKER);
		}
	}
}

/*
 * dopushdef - install a definition in the hash table
 *      without removing a previous definition. Since
 *      each new entry is entered in *front* of the
 *      hash bucket, it hides a previous definition from
 *      lookup.
 */
static void
dopushdef(const char *name, const char *defn)
{
	if (!*name)
		errx(1, "%s at line %lu: null definition", CURRENT_NAME,
		    CURRENT_LINE);
	macro_pushdef(name, defn);
}

/*
 * dump_one_def - dump the specified definition.
 */
static void
dump_one_def(const char *name, struct macro_definition *p)
{
	if (mimic_gnu) {
		if ((p->type & TYPEMASK) == MACRTYPE)
			fprintf(traceout, "%s:\t%s\n", name, p->defn);
		else {
			fprintf(traceout, "%s:\t<%s>\n", name, p->defn);
	    	}
	} else
		fprintf(traceout, "`%s'\t`%s'\n", name, p->defn);
}

/*
 * dodumpdef - dump the specified definitions in the hash
 *      table to stderr. If nothing is specified, the entire
 *      hash table is dumped.
 */
static void
dodump(const char *argv[], int argc)
{
	int n;
	struct macro_definition *p;

	if (argc > 2) {
		for (n = 2; n < argc; n++)
			if ((p = lookup_macro_definition(argv[n])) != NULL)
				dump_one_def(argv[n], p);
	} else
		macro_for_all(dump_one_def);
}

/*
 * dotrace - mark some macros as traced/untraced depending upon on.
 */
static void
dotrace(const char *argv[], int argc, int on)
{
	int n;

	if (argc > 2) {
		for (n = 2; n < argc; n++)
			mark_traced(argv[n], on);
	} else
		mark_traced(NULL, on);
}

/*
 * doifelse - select one of two alternatives - loop.
 */
static void
doifelse(const char *argv[], int argc)
{
	cycle {
		if (STREQ(argv[2], argv[3]))
			pbstr(argv[4]);
		else if (argc == 6)
			pbstr(argv[5]);
		else if (argc > 6) {
			argv += 3;
			argc -= 3;
			continue;
		}
		break;
	}
}

/*
 * doinclude - include a given file.
 */
static int
doincl(const char *ifile)
{
	if (ilevel + 1 == MAXINP)
		errx(1, "%s at line %lu: too many include files.",
		    CURRENT_NAME, CURRENT_LINE);
	if (fopen_trypath(infile+ilevel+1, ifile) != NULL) {
		ilevel++;
		bbase[ilevel] = bufbase = bp;
		return (1);
	} else
		return (0);
}

#ifdef EXTENDED
/*
 * dopaste - include a given file without any
 *           macro processing.
 */
static int
dopaste(const char *pfile)
{
	FILE *pf;
	int c;

	if ((pf = fopen(pfile, "r")) != NULL) {
		if (synch_lines)
		    fprintf(active, "#line 1 \"%s\"\n", pfile);
		while ((c = getc(pf)) != EOF)
			putc(c, active);
		(void) fclose(pf);
		emit_synchline();
		return (1);
	} else
		return (0);
}
#endif

static void
gnu_dochq(const char *argv[], int ac)
{
	/* In gnu-m4 mode, the only way to restore quotes is to have no
	 * arguments at all. */
	if (ac == 2) {
		lquote[0] = LQUOTE, lquote[1] = EOS;
		rquote[0] = RQUOTE, rquote[1] = EOS;
	} else {
		strlcpy(lquote, argv[2], sizeof(lquote));
		if(ac > 3)
			strlcpy(rquote, argv[3], sizeof(rquote));
		else
			rquote[0] = EOS;
	}
}

/*
 * dochq - change quote characters
 */
static void
dochq(const char *argv[], int argc)
{
	if (argc > 2) {
		if (*argv[2])
			strlcpy(lquote, argv[2], sizeof(lquote));
		else {
			lquote[0] = LQUOTE;
			lquote[1] = EOS;
		}
		if (argc > 3) {
			if (*argv[3])
				strlcpy(rquote, argv[3], sizeof(rquote));
		} else
			strlcpy(rquote, lquote, sizeof(rquote));
	} else {
		lquote[0] = LQUOTE, lquote[1] = EOS;
		rquote[0] = RQUOTE, rquote[1] = EOS;
	}
}

static void
gnu_dochc(const char *argv[], int ac)
{
	/* In gnu-m4 mode, no arguments mean no comment
	 * arguments at all. */
	if (ac == 2) {
		scommt[0] = EOS;
		ecommt[0] = EOS;
	} else {
		if (*argv[2])
			strlcpy(scommt, argv[2], sizeof(scommt));
		else
			scommt[0] = SCOMMT, scommt[1] = EOS;
		if(ac > 3 && *argv[3])
			strlcpy(ecommt, argv[3], sizeof(ecommt));
		else
			ecommt[0] = ECOMMT, ecommt[1] = EOS;
	}
}
/*
 * dochc - change comment characters
 */
static void
dochc(const char *argv[], int argc)
{
	if (argc > 2) {
		if (*argv[2])
			strlcpy(scommt, argv[2], sizeof(scommt));
		if (argc > 3) {
			if (*argv[3])
				strlcpy(ecommt, argv[3], sizeof(ecommt));
		}
		else
			ecommt[0] = ECOMMT, ecommt[1] = EOS;
	}
	else {
		scommt[0] = SCOMMT, scommt[1] = EOS;
		ecommt[0] = ECOMMT, ecommt[1] = EOS;
	}
}

/*
 * dodivert - divert the output to a temporary file
 */
static void
dodiv(int n)
{
	int fd;

	oindex = n;
	if (n >= maxout) {
		if (mimic_gnu)
			resizedivs(n + 10);
		else
			n = 0;		/* bitbucket */
    	}

	if (n < 0)
		n = 0;		       /* bitbucket */
	if (outfile[n] == NULL) {
		char fname[] = _PATH_DIVNAME;

		if ((fd = mkstemp(fname)) < 0 || 
			(outfile[n] = fdopen(fd, "w+")) == NULL)
				err(1, "%s: cannot divert", fname);
		if (unlink(fname) == -1)
			err(1, "%s: cannot unlink", fname);
	}
	active = outfile[n];
}

/*
 * doundivert - undivert a specified output, or all
 *              other outputs, in numerical order.
 */
static void
doundiv(const char *argv[], int argc)
{
	int ind;
	int n;

	if (argc > 2) {
		for (ind = 2; ind < argc; ind++) {
			n = atoi(argv[ind]);
			if (n > 0 && n < maxout && outfile[n] != NULL)
				getdiv(n);

		}
	}
	else
		for (n = 1; n < maxout; n++)
			if (outfile[n] != NULL)
				getdiv(n);
}

/*
 * dosub - select substring
 */
static void
dosub(const char *argv[], int argc)
{
	const char *ap, *fc, *k;
	int nc;

	ap = argv[2];		       /* target string */
#ifdef EXPR
	fc = ap + expr(argv[3]);       /* first char */
#else
	fc = ap + atoi(argv[3]);       /* first char */
#endif
	nc = strlen(fc);
	if (argc >= 5)
#ifdef EXPR
		nc = min(nc, expr(argv[4]));
#else
		nc = min(nc, atoi(argv[4]));
#endif
	if (fc >= ap && fc < ap + strlen(ap))
		for (k = fc + nc - 1; k >= fc; k--)
			putback(*k);
}

/*
 * map:
 * map every character of s1 that is specified in from
 * into s3 and replace in s. (source s1 remains untouched)
 *
 * This is a standard implementation of map(s,from,to) function of ICON
 * language. Within mapvec, we replace every character of "from" with
 * the corresponding character in "to". If "to" is shorter than "from",
 * than the corresponding entries are null, which means that those
 * characters dissapear altogether. Furthermore, imagine
 * map(dest, "sourcestring", "srtin", "rn..*") type call. In this case,
 * `s' maps to `r', `r' maps to `n' and `n' maps to `*'. Thus, `s'
 * ultimately maps to `*'. In order to achieve this effect in an efficient
 * manner (i.e. without multiple passes over the destination string), we
 * loop over mapvec, starting with the initial source character. if the
 * character value (dch) in this location is different than the source
 * character (sch), sch becomes dch, once again to index into mapvec, until
 * the character value stabilizes (i.e. sch = dch, in other words
 * mapvec[n] == n). Even if the entry in the mapvec is null for an ordinary
 * character, it will stabilize, since mapvec[0] == 0 at all times. At the
 * end, we restore mapvec* back to normal where mapvec[n] == n for
 * 0 <= n <= 127. This strategy, along with the restoration of mapvec, is
 * about 5 times faster than any algorithm that makes multiple passes over
 * destination string.
 */
static void
map(char *dest, const char *src, const char *from, const char *to)
{
	const char *tmp;
	unsigned char sch, dch;
	static char frombis[257];
	static char tobis[257];
	static unsigned char mapvec[256] = {
	    0, 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, 34, 35,
	    36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
	    53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69,
	    70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86,
	    87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102,
	    103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
	    116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
	    129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141,
	    142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154,
	    155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167,
	    168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180,
	    181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193,
	    194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206,
	    207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,
	    220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232,
	    233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,
	    246, 247, 248, 249, 250, 251, 252, 253, 254, 255
	};

	if (*src) {
		if (mimic_gnu) {
			/*
			 * expand character ranges on the fly
			 */
			from = handledash(frombis, frombis + 256, from);
			to = handledash(tobis, tobis + 256, to);
		}
		tmp = from;
	/*
	 * create a mapping between "from" and
	 * "to"
	 */
		while (*from)
			mapvec[(unsigned char)(*from++)] = (*to) ? 
				(unsigned char)(*to++) : 0;

		while (*src) {
			sch = (unsigned char)(*src++);
			dch = mapvec[sch];
			while (dch != sch) {
				sch = dch;
				dch = mapvec[sch];
			}
			if ((*dest = (char)dch))
				dest++;
		}
	/*
	 * restore all the changed characters
	 */
		while (*tmp) {
			mapvec[(unsigned char)(*tmp)] = (unsigned char)(*tmp);
			tmp++;
		}
	}
	*dest = '\0';
}


/*
 * handledash:
 *  use buffer to copy the src string, expanding character ranges
 * on the way.
 */
static const char *
handledash(char *buffer, char *end, const char *src)
{
	char *p;
	
	p = buffer;
	while(*src) {
		if (src[1] == '-' && src[2]) {
			unsigned char i;
			for (i = (unsigned char)src[0]; 
			    i <= (unsigned char)src[2]; i++) {
				*p++ = i;
				if (p == end) {
					*p = '\0';
					return buffer;
				}
			}
			src += 3;
		} else
			*p++ = *src++;
		if (p == end)
			break;
	}
	*p = '\0';
	return buffer;
}