/* $NetBSD: cat.c,v 1.57 2016/06/16 00:52:37 sevan 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.
 */

#define _DEFAULT_SOURCE

#include <sys/param.h>
#include <sys/stat.h>

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

static int bflag, eflag, fflag, lflag, nflag, sflag, tflag, vflag;
static size_t bsize;
static int rval;
static const char *filename;
static const char *__progname;

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;
  struct flock stdout_lock;

  __progname = basename(argv[0]);
  (void)setlocale(LC_ALL, "");

  while ((ch = getopt(argc, argv, "B:beflnstuv")) != -1)
    switch (ch) {
    case 'B':
      bsize = (size_t)strtol(optarg, NULL, 0);
      break;
    case 'b':
      bflag = nflag = 1; /* -b implies -n */
      break;
    case 'e':
      eflag = vflag = 1; /* -e implies -v */
      break;
    case 'f':
      fflag = 1;
      break;
    case 'l':
      lflag = 1;
      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:
    case '?':
      (void)fprintf(stderr,
                    "Usage: %s [-beflnstuv] [-B bsize] [-] "
                    "[file ...]\n",
                    __progname);
      return EXIT_FAILURE;
    }
  argv += optind;

  if (lflag) {
    stdout_lock.l_len = 0;
    stdout_lock.l_start = 0;
    stdout_lock.l_type = F_WRLCK;
    stdout_lock.l_whence = SEEK_SET;
    if (fcntl(STDOUT_FILENO, F_SETLKW, &stdout_lock) == -1)
      err(EXIT_FAILURE, "stdout");
  }

  if (bflag || eflag || nflag || sflag || tflag || vflag)
    cook_args(argv);
  else
    raw_args(argv);
  if (fclose(stdout))
    err(EXIT_FAILURE, "stdout");
  return rval;
}

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

  fp = stdin;
  filename = "stdin";
  do {
    if (*argv) {
      if (!strcmp(*argv, "-"))
        fp = stdin;
      else if ((fp = fopen(*argv, fflag ? "rf" : "r")) == NULL) {
        warn("%s", *argv);
        rval = EXIT_FAILURE;
        ++argv;
        continue;
      }
      filename = *argv++;
    }
    cook_buf(fp);
    if (fp != stdin)
      (void)fclose(fp);
    else
      clearerr(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) {
        if (!bflag || ch != '\n') {
          (void)fprintf(stdout, "%6d\t", ++line);
          if (ferror(stdout))
            break;
        } else if (eflag) {
          (void)fprintf(stdout, "%6s\t", "");
          if (ferror(stdout))
            break;
        }
      }
    }
    if (ch == '\n') {
      if (eflag)
        if (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 = EXIT_FAILURE;
    clearerr(fp);
  }
  if (ferror(stdout))
    err(EXIT_FAILURE, "stdout");
}

void raw_args(char **argv) {
  int fd;

  fd = fileno(stdin);
  filename = "stdin";
  do {
    if (*argv) {
      if (!strcmp(*argv, "-")) {
        fd = fileno(stdin);
        if (fd < 0)
          goto skip;
      } else if (fflag) {
        struct stat st;
        fd = open(*argv, O_RDONLY | O_NONBLOCK, 0);
        if (fd < 0)
          goto skip;

        if (fstat(fd, &st) == -1) {
          close(fd);
          goto skip;
        }
        if (!S_ISREG(st.st_mode)) {
          close(fd);
          warnx("%s: not a regular file", *argv);
          goto skipnomsg;
        }
      } else if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
      skip:
        warn("%s", *argv);
      skipnomsg:
        rval = EXIT_FAILURE;
        ++argv;
        continue;
      }
      filename = *argv++;
    } else if (fd < 0) {
      err(EXIT_FAILURE, "stdin");
    }
    raw_cat(fd);
    if (fd != fileno(stdin))
      (void)close(fd);
  } while (*argv);
}

void raw_cat(int rfd) {
  static char *buf;
  static char fb_buf[BUFSIZ];

  ssize_t nr, nw, off;
  int wfd;

  wfd = fileno(stdout);
  if (wfd < 0)
    err(EXIT_FAILURE, "stdout");
  if (buf == NULL) {
    struct stat sbuf;

    if (bsize == 0) {
      if (fstat(wfd, &sbuf) == 0 && sbuf.st_blksize > 0 &&
          (size_t)sbuf.st_blksize > sizeof(fb_buf))
        bsize = sbuf.st_blksize;
    }
    if (bsize > sizeof(fb_buf)) {
      buf = malloc(bsize);
      if (buf == NULL)
        warnx("malloc, using %zu buffer", bsize);
    }
    if (buf == NULL) {
      bsize = sizeof(fb_buf);
      buf = fb_buf;
    }
  }
  while ((nr = read(rfd, buf, bsize)) > 0)
    for (off = 0; nr; nr -= nw, off += nw)
      if ((nw = write(wfd, buf + off, (size_t)nr)) < 0)
        err(EXIT_FAILURE, "stdout");
  if (nr < 0) {
    warn("%s", filename);
    rval = EXIT_FAILURE;
  }
}
