/*	$OpenBSD: cat.c,v 1.23 2015/10/09 01:37:06 deraadt 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 <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

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

extern char *__progname;

int bflag, eflag, nflag, sflag, tflag, vflag;
int rval;
char *filename;

void cook_args(char *argv[]);
void cook_buf(FILE *);
void raw_args(char *argv[]);
void raw_cat(int);

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

	setlocale(LC_ALL, "");

	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':
			setbuf(stdout, NULL);
			break;
		case 'v':
			vflag = 1;
			break;
		default:
			(void)fprintf(stderr,
			    "usage: %s [-benstuv] [file ...]\n", __progname);
			exit(1);
			/* NOTREACHED */
		}
	argv += optind;

	if (bflag || eflag || nflag || sflag || tflag || vflag)
		cook_args(argv);
	else
		raw_args(argv);
	if (fclose(stdout))
		err(1, "stdout");
	exit(rval);
	/* NOTREACHED */
}

void
cook_args(char **argv)
{
	FILE *fp;

	fp = stdin;
	filename = "stdin";
	do {
		if (*argv) {
			if (!strcmp(*argv, "-"))
				fp = stdin;
			else if ((fp = fopen(*argv, "r")) == NULL) {
				warn("%s", *argv);
				rval = 1;
				++argv;
				continue;
			}
			filename = *argv++;
		}
		cook_buf(fp);
		if (fp == stdin)
			clearerr(fp);
		else
			(void)fclose(fp);
	} while (*argv);
}

void
cook_buf(FILE *fp)
{
	int ch, gobble, line, 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 && (!bflag || ch != '\n')) {
				(void)fprintf(stdout, "%6d\t", ++line);
				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_args(char **argv)
{
	int fd;

	fd = fileno(stdin);
	filename = "stdin";
	do {
		if (*argv) {
			if (!strcmp(*argv, "-"))
				fd = fileno(stdin);
			else if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
				warn("%s", *argv);
				rval = 1;
				++argv;
				continue;
			}
			filename = *argv++;
		}
		raw_cat(fd);
		if (fd != fileno(stdin))
			(void)close(fd);
	} while (*argv);
}

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