usr/src/usr.bin/tr/tr.c

/*
 * Copyright (c) 1988 The Regents of the University of California.
 * All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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
char copyright[] =
"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)tr.c        4.7 (Berkeley) 7/23/90";
#endif /* not lint */

#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>

#define NCHARS  256                             /* size of u_char */
#define OOBCH   257                             /* out of band value */

typedef struct {
        char *str;
        int lastch, endrange;
        enum { NORM, INRANGE, EOS } state;
} STR;

main(argc, argv)
        int argc;
        char **argv;
{
        extern int optind;
        STR s1, s2;
        register int ch, indx, lastch;
        int cflag, dflag, sflag;
        u_char *tp, tab[NCHARS], squeeze[NCHARS];

        cflag = dflag = sflag = 0;
        while ((ch = getopt(argc, argv, "cds")) != EOF)
                switch((char)ch) {
                case 'c':
                        cflag = 1;
                        break;
                case 'd':
                        dflag = 1;
                        break;
                case 's':
                        sflag = 1;
                        break;
                case '?':
                default:
                        fprintf(stderr,
                            "usage: tr [-cds] [string1 [string2]]\n");
                        exit(1);
                }
        argc -= optind;
        argv += optind;

        /*
         * the original tr was amazingly tolerant of the command line.
         * Neither -c or -s have any effect unless there are two strings.
         * Extra arguments are silently ignored.  Bag this noise, they
         * should all be errors.
         */
        if (argc < 2 && !dflag) {
                while ((ch = getchar()) != EOF)
                        putchar(ch);
                exit(0);
        }

        bzero(tab, NCHARS);
        if (sflag) {
                s1.str = argv[1];
                s1.state = NORM;
                s1.lastch = OOBCH;
                while (next(&s1))
                        squeeze[s1.lastch] = 1;
        }
        if (dflag) {
                s1.str = argv[0];
                s1.state = NORM;
                s1.lastch = OOBCH;
                while (next(&s1))
                        tab[s1.lastch] = 1;
                if (cflag)
                        for (tp = tab, indx = 0; indx < NCHARS; ++tp, ++indx)
                                *tp = !*tp;
                if (sflag)
                        for (lastch = OOBCH; (ch = getchar()) != EOF;) {
                                if (tab[ch] || (squeeze[ch] && lastch == ch))
                                        continue;
                                lastch = ch;
                                putchar(ch);
                        }
                else
                        while ((ch = getchar()) != EOF)
                                if (!tab[ch])
                                        putchar(ch);
        } else {
                s1.str = argv[0];
                s2.str = argv[1];
                s1.state = s2.state = NORM;
                s1.lastch = s2.lastch = OOBCH;
                if (cflag) {
                        /*
                         * if cflag is set, tr just pretends it only got one
                         * character in string2.  As reasonable as anything
                         * else.  Should really be an error.
                         */
                        while (next(&s2));
                        lastch = s2.lastch;
                        for (tp = tab, indx = 0; indx < NCHARS; ++tp, ++indx)
                                *tp = lastch;
                        while (next(&s1))
                                tab[s1.lastch] = s1.lastch;
                } else {
                        for (tp = tab, indx = 0; indx < NCHARS; ++tp, ++indx)
                                *tp = indx;
                        while (next(&s1)) {
                                (void)next(&s2);
                                tab[s1.lastch] = s2.lastch;
                        }
                }
                if (sflag)
                        for (lastch = OOBCH; (ch = getchar()) != EOF;) {
                                ch = tab[ch];
                                if (squeeze[ch] && lastch == ch)
                                        continue;
                                lastch = ch;
                                putchar(ch);
                        }
                else
                        while ((ch = getchar()) != EOF)
                                putchar((int)tab[ch]);
        }
        exit(0);
}

next(s)
        register STR *s;
{
        register int ch;

        if (s->state == EOS)
                return(0);
        if (s->state == INRANGE) {
                if (++s->lastch == s->endrange)
                        s->state = NORM;
                return(1);
        }
        if (!(ch = *s->str++)) {
                s->state = EOS;
                return(0);
        }
        if (ch == '\\') {                       /* \### */
                s->lastch = tran(s);
                return(1);
        }
        if (ch == '-') {                        /* ranges */
                if (s->lastch == OOBCH)         /* "-a" */
                        goto fail2;
                if (!(ch = *s->str++))          /* "a-" */
                        goto fail1;
                if (ch == '\\')                 /* \### */
                        ch = tran(s);
                if (s->lastch > ch) {           /* "z-a" */
fail1:                  --s->str;
fail2:                  s->lastch = '-';
                        return(1);
                }
                if (s->lastch == ch)            /* "a-a" */
                        return(next(s));
                s->state = INRANGE;             /* "a-z" */
                s->endrange = ch;
                return(1);
        }
        s->lastch = ch;
        return(1);
}

/*
 * Translate \-escapes.  Up to 3 octal digits => char; no digits => literal.
 * Unadorned backslash "\" is like \000.
 */
tran(s)
        register STR *s;
{
        register int ch, cnt = 0, val = 0;

        for (;;) {
                ch = *s->str++;
                if (!isascii(ch) || !isdigit(ch) || ++cnt > 3)
                        break;
                val = val * 8 + ch - '0';
        }
        if (cnt || ch == 0)
                s->str--;
        return (cnt ? val : ch);
}