/*      $OpenBSD: cat.c,v 1.34 2022/02/09 01:58:57 cheloha Exp $        */
/*      $NetBSD: cat.c,v 1.11 1995/09/07 06:12:54 jtc 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
 * Kevin Fall.
 *
 * 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/types.h>
#include <sys/stat.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define MAXIMUM(a, b)   (((a) > (b)) ? (a) : (b))

int bflag, eflag, nflag, sflag, tflag, vflag;
int rval;

void cat_file(const char *);
void cook_buf(FILE *, const char *);
void raw_cat(int, const char *);

int
main(int argc, char *argv[])
{
        int ch;

        if (pledge("stdio rpath", NULL) == -1)
                err(1, "pledge");

        while ((ch = getopt(argc, argv, "benstuv")) != -1) {
                switch (ch) {
                case 'b':
                        bflag = nflag = 1;      /* -b implies -n */
                        break;
                case 'e':
                        eflag = vflag = 1;      /* -e implies -v */
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 's':
                        sflag = 1;
                        break;
                case 't':
                        tflag = vflag = 1;      /* -t implies -v */
                        break;
                case 'u':
                        setvbuf(stdout, NULL, _IONBF, 0);
                        break;
                case 'v':
                        vflag = 1;
                        break;
                default:
                        fprintf(stderr, "usage: %s [-benstuv] [file ...]\n",
                            getprogname());
                        return 1;
                }
        }
        argc -= optind;
        argv += optind;

        if (argc == 0) {
                if (pledge("stdio", NULL) == -1)
                        err(1, "pledge");

                cat_file(NULL);
        } else {
                for (; *argv != NULL; argv++)
                        cat_file(*argv);
        }
        if (fclose(stdout))
                err(1, "stdout");
        return rval;
}

void
cat_file(const char *path)
{
        FILE *fp;
        int fd;

        if (bflag || eflag || nflag || sflag || tflag || vflag) {
                if (path == NULL || strcmp(path, "-") == 0) {
                        cook_buf(stdin, "stdin");
                        clearerr(stdin);
                } else {
                        if ((fp = fopen(path, "r")) == NULL) {
                                warn("%s", path);
                                rval = 1;
                                return;
                        }
                        cook_buf(fp, path);
                        fclose(fp);
                }
        } else {
                if (path == NULL || strcmp(path, "-") == 0) {
                        raw_cat(STDIN_FILENO, "stdin");
                } else {
                        if ((fd = open(path, O_RDONLY)) == -1) {
                                warn("%s", path);
                                rval = 1;
                                return;
                        }
                        raw_cat(fd, path);
                        close(fd);
                }
        }
}

void
cook_buf(FILE *fp, const char *filename)
{
        unsigned long long line;
        int ch, gobble, prev;

        line = gobble = 0;
        for (prev = '\n'; (ch = getc(fp)) != EOF; prev = ch) {
                if (prev == '\n') {
                        if (sflag) {
                                if (ch == '\n') {
                                        if (gobble)
                                                continue;
                                        gobble = 1;
                                } else
                                        gobble = 0;
                        }
                        if (nflag) {
                                if (!bflag || ch != '\n') {
                                        fprintf(stdout, "%6llu\t", ++line);
                                        if (ferror(stdout))
                                                break;
                                } else if (eflag) {
                                        (void)fprintf(stdout, "%6s\t", "");
                                        if (ferror(stdout))
                                                break;
                                }
                        }
                }
                if (ch == '\n') {
                        if (eflag && putchar('$') == EOF)
                                break;
                } else if (ch == '\t') {
                        if (tflag) {
                                if (putchar('^') == EOF || putchar('I') == EOF)
                                        break;
                                continue;
                        }
                } else if (vflag) {
                        if (!isascii(ch)) {
                                if (putchar('M') == EOF || putchar('-') == EOF)
                                        break;
                                ch = toascii(ch);
                        }
                        if (iscntrl(ch)) {
                                if (putchar('^') == EOF ||
                                    putchar(ch == '\177' ? '?' :
                                    ch | 0100) == EOF)
                                        break;
                                continue;
                        }
                }
                if (putchar(ch) == EOF)
                        break;
        }
        if (ferror(fp)) {
                warn("%s", filename);
                rval = 1;
                clearerr(fp);
        }
        if (ferror(stdout))
                err(1, "stdout");
}

void
raw_cat(int rfd, const char *filename)
{
        int wfd;
        ssize_t nr, nw, off;
        static size_t bsize;
        static char *buf = NULL;
        struct stat sbuf;

        wfd = fileno(stdout);
        if (buf == NULL) {
                if (fstat(wfd, &sbuf) == -1)
                        err(1, "stdout");
                bsize = MAXIMUM(sbuf.st_blksize, BUFSIZ);
                if ((buf = malloc(bsize)) == NULL)
                        err(1, NULL);
        }
        while ((nr = read(rfd, buf, bsize)) != -1 && nr != 0) {
                for (off = 0; nr; nr -= nw, off += nw) {
                        if ((nw = write(wfd, buf + off, nr)) == -1 || nw == 0)
                                err(1, "stdout");
                }
        }
        if (nr == -1) {
                warn("%s", filename);
                rval = 1;
        }
}