/*      $NetBSD: cut.c,v 1.33 2026/04/05 03:03:56 gutteridge 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
 * Adam S. Moskowitz of Menlo Consulting and Marciano Pitargue.
 *
 * 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.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)cut.c       8.3 (Berkeley) 5/4/95";
#endif
__RCSID("$NetBSD: cut.c,v 1.33 2026/04/05 03:03:56 gutteridge Exp $");
#endif /* not lint */

#include <sys/param.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
#include <wchar.h>

static int      bflag;
static int      cflag;
static char     dchar;
static int      dflag;
static int      fflag;
static int      nflag;
static int      sflag;

static void     b_cut(FILE *, const char *);
static void     b_n_cut(FILE *, const char *);
static void     c_cut(FILE *, const char *);
static void     f_cut(FILE *, const char *);
static void     get_list(char *);
static void     usage(void) __dead;

int
main(int argc, char *argv[])
{
        FILE *fp;
        void (*fcn)(FILE *, const char *);
        int ch, rval;

        fcn = NULL;
        (void)setlocale(LC_ALL, "");

        dchar = '\t';                   /* default delimiter is \t */

        while ((ch = getopt(argc, argv, "b:c:d:f:sn")) != -1)
                switch(ch) {
                case 'b':
                        fcn = b_cut;
                        get_list(optarg);
                        bflag = 1;
                        break;
                case 'c':
                        fcn = c_cut;
                        get_list(optarg);
                        cflag = 1;
                        break;
                case 'd':
                        dchar = *optarg;
                        dflag = 1;
                        break;
                case 'f':
                        get_list(optarg);
                        fcn = f_cut;
                        fflag = 1;
                        break;
                case 's':
                        sflag = 1;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (bflag + cflag + fflag != 1 ||
            (nflag && !bflag) ||
            ((dflag || sflag) && !fflag))
                usage();

        if (nflag)
                fcn = b_n_cut;

        rval = 0;
        if (*argv)
                for (; *argv; ++argv) {
                        if (strcmp(*argv, "-") == 0)
                                fcn(stdin, "stdin");
                        else {
                                if ((fp = fopen(*argv, "r"))) {
                                        fcn(fp, *argv);
                                        (void)fclose(fp);
                                } else {
                                        rval = 1;
                                        warn("%s", *argv);
                                }
                        }
                }
        else
                fcn(stdin, "stdin");
        return(rval);
}

static size_t autostart, autostop, maxval;

static char *positions = NULL;
static size_t numpositions = 0;
#define ALLOC_CHUNK     _POSIX2_LINE_MAX        /* malloc granularity */

static void
get_list(char *list)
{
        size_t setautostart, start, stop;
        char *p, *pos;

        if (positions == NULL) {
                numpositions = ALLOC_CHUNK;
                positions = ecalloc(numpositions, sizeof(*positions));
        }

        /*
         * Set a byte in the positions array to indicate if a field or
         * column is to be selected; use +1, it's 1-based, not 0-based.
         * Numbers and number ranges may be overlapping, repeated, and in
         * any order. We handle "-3-5" although there's no real reason to.
         */
        for (; (p = strtok(list, ", \t")) != NULL; list = NULL) {
                setautostart = start = stop = 0;
                if (*p == '-') {
                        ++p;
                        setautostart = 1;
                }
                if (isdigit((unsigned char)*p)) {
                        start = stop = strtol(p, &p, 10);
                        if (setautostart && start > autostart)
                                autostart = start;
                }
                if (*p == '-') {
                        if (isdigit((unsigned char)p[1]))
                                stop = strtol(p + 1, &p, 10);
                        if (*p == '-') {
                                ++p;
                                if (!autostop || autostop > stop)
                                        autostop = stop;
                        }
                }
                if (*p)
                        errx(1, "[-bcf] list: illegal list value");
                if (!stop || !start)
                        errx(1, "[-bcf] list: values may not include zero");
                if (stop + 1 > numpositions) {
                        size_t newsize;
                        newsize = roundup(stop + 1, ALLOC_CHUNK);
                        positions = erealloc(positions, newsize);
                        (void)memset(positions + numpositions, 0,
                            newsize - numpositions);
                        numpositions = newsize;
                }
                if (maxval < stop)
                        maxval = stop;
                for (pos = positions + start; start++ <= stop; pos++)
                        *pos = 1;
        }

        /* overlapping ranges */
        if (autostop && maxval > autostop)
                maxval = autostop;

        /* set autostart */
        if (autostart)
                (void)memset(positions + 1, '1', autostart);
}

/*
 * Cut based on byte positions, taking care not to split multibyte characters.
 * Although this function also handles the case where -n is not specified,
 * b_cut() ought to be much faster.
 */
static void
b_n_cut(FILE *fp, const char *fname)
{
        size_t col, i, lbuflen;
        char *lbuf;
        int canwrite, clen, warned;
        mbstate_t mbs;

        memset(&mbs, 0, sizeof(mbs));
        warned = 0;
        while ((lbuf = fgetln(fp, &lbuflen)) != NULL) {
                for (col = 0; lbuflen > 0; col += clen) {
                        if ((clen = mbrlen(lbuf, lbuflen, &mbs)) < 0) {
                                if (!warned) {
                                        warn("%s", fname);
                                        warned = 1;
                                }
                                memset(&mbs, 0, sizeof(mbs));
                                clen = 1;
                        }
                        if (clen == 0 || *lbuf == '\n')
                                break;
                        if (col < maxval && !positions[1 + col]) {
                                /*
                                 * Print the character if (1) after an initial
                                 * segment of un-selected bytes, the rest of
                                 * it is selected, and (2) the last byte is
                                 * selected.
                                 */
                                i = col;
                                while (i < col + clen && i < maxval &&
                                    !positions[1 + i])
                                        i++;
                                canwrite = i < col + clen;
                                for (; i < col + clen && i < maxval; i++)
                                        canwrite &= positions[1 + i];
                                if (canwrite)
                                        fwrite(lbuf, 1, clen, stdout);
                        } else {
                                /*
                                 * Print the character if all of it has
                                 * been selected.
                                 */
                                canwrite = 1;
                                for (i = col; i < col + clen; i++)
                                        if ((i >= maxval && !autostop) ||
                                            (i < maxval && !positions[1 + i])) {
                                                canwrite = 0;
                                                break;
                                        }
                                if (canwrite)
                                        fwrite(lbuf, 1, clen, stdout);
                        }
                        lbuf += clen;
                        lbuflen -= clen;
                }
                if (lbuflen > 0)
                        putchar('\n');
        }
}

static void
/*ARGSUSED*/
f_cut(FILE *fp, const char *fname __unused)
{
        size_t len;
        int ch, field, isdelim, output;
        char *lbuf, *pos, *p, sep, *tbuf;

        for (sep = dchar, tbuf = NULL; (lbuf = fgetln(fp, &len)) != NULL;) {
                output = 0;
                if (lbuf[len - 1] != '\n') {
                        /* no newline at the end of the last line so add one */
                        if ((tbuf = (char *)malloc(len + 1)) == NULL)
                                err(1, NULL);
                        (void)memcpy(tbuf, lbuf, len);
                        tbuf[len++] = '\n';
                        lbuf = tbuf;
                }
                for (isdelim = 0, p = lbuf;; ++p) {
                        ch = *p;
                        /* this should work if newline is delimiter */
                        if (ch == sep)
                                isdelim = 1;
                        if (ch == '\n') {
                                if (!isdelim && !sflag)
                                        (void)fwrite(lbuf, len, 1, stdout);
                                break;
                        }
                }
                if (!isdelim)
                        continue;

                pos = positions + 1;
                for (field = maxval, p = lbuf; field; --field, ++pos) {
                        if (*pos) {
                                if (output++)
                                        (void)putchar(sep);
                                while ((ch = *p++) != '\n' && ch != sep)
                                        (void)putchar(ch);
                        } else {
                                while ((ch = *p++) != '\n' && ch != sep)
                                        continue;
                        }
                        if (ch == '\n')
                                break;
                }
                if (ch != '\n') {
                        if (autostop) {
                                if (output)
                                        (void)putchar(sep);
                                for (; (ch = *p) != '\n'; ++p)
                                        (void)putchar(ch);
                        } else
                                for (; (ch = *p) != '\n'; ++p);
                }
                (void)putchar('\n');
                if (tbuf) {
                        free(tbuf);
                        tbuf = NULL;
                }
        }
        if (tbuf)
                free(tbuf);
}

static void
usage(void)
{
        (void)fprintf(stderr, "usage:\tcut -b list [-n] [file ...]\n"
            "\tcut -c list [file ...]\n"
            "\tcut -f list [-d string] [-s] [file ...]\n");
        exit(1);
}

/* make b_cut(): */
#define CUT_BYTE 1
#include "x_cut.c"
#undef CUT_BYTE

/* make c_cut(): */
#define CUT_BYTE 0
#include "x_cut.c"
#undef CUT_BYTE