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/* Copyright (c) 2008, Tim Post <tinkertim@gmail.com>

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * Redistributions of source code must retain the above copyright notice, this

 * list of conditions and the following disclaimer.

 *

 * 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.

 *

 * Neither the name of the original program's authors 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <getopt.h>

#include <string.h>

#include <fcntl.h>

#include "config.h"

#include "util.h"

#include "errors.h"

#include "entry.h"

#include "cat.h"

#include "cmds.h"

static char *cmdname = "cat";

#define CAT_VERSION "0.0.1"

#define CAT_DEFAULT_BUFLEN 1024

static char *cat_oops = "That option is not yet supported\n";

static struct option long_options[] = {

    { "help", no_argument, 0, 'h' },

    { "version", no_argument, 0, 'v' },

    { "head", required_argument, 0, 'H' },

    { "tail", required_argument, 0, 't' },

    { "buffer", required_argument, 0, 'b' },

    { "more", no_argument, 0, 'm' },

    { 0, 0, 0, 0 }

};

/* Dispays help for cat in various levels */

void * help_cmd_cat(unsigned int level)

{

    if (level == HELP_SHORT) {

        printf("`%s' shows the contents of files\n", cmdname);

    } else {

        help_cmd_cat(HELP_SHORT);

        printf(

        "Usage:  %s [options] <file1> [file2] [...]\n"

        "Options:\n"

        "  -h, --help       A short option summary\n"

        "  -v, --version    Print version information and exit\n"

        "  -H, --head ##    Print only the first ## bytes\n"

        "  -t, --tail ##    Print only the last ## bytes\n"

        "  -b, --buffer ##  Set the read buffer size to ##\n"

        "  -m, --more       Pause after each screen full\n"

        "Currently, %s is under development, some options don't work.\n",

        cmdname, cmdname);

    }

    return CMD_VOID;

}

unsigned int cat_file(const char *fname, size_t blen)

{

    int fd, bytes = 0, count = 0, reads = 0;

    off_t total = 0;

    char *buff = NULL;

    if (-1 == (fd = open(fname, O_RDONLY))) {

        printf("Unable to open %s\n", fname);

        return 1;

    }

    total = lseek(fd, 0, SEEK_END);

    lseek(fd, 0, SEEK_SET);

    if (NULL == (buff = (char *) malloc(blen + 1))) {

        close(fd);

        printf("Unable to allocate enough memory to read %s\n",

            fname);

        return 1;

    }

    do {

        memset(buff, 0, sizeof(buff));

        bytes = read(fd, buff, blen);

        if (bytes > 0) {

            count += bytes;

            if (bytes < blen)

                buff[bytes] = '\0';

            printf(buff);

            reads++;

        }

    } while (bytes > 0);

    close(fd);

    if (bytes == -1) {

        printf("Error reading %s\n", fname);

        free(buff);

        return 1;

    }

    /* Debug stuff, newline not added purposefully */

    printf("** %s is a file with the size of %ld bytes\n",

        fname, total);

    printf( "** %d bytes were read in a buffer of %d bytes in %d reads\n",

        count, blen, reads);

    printf("** Read %s\n", count == total ? "Succeeded" : "Failed");

    free(buff);

    return 0;

}

/* Main entry point for cat, accepts an array of arguments */

int * cmd_cat(char **argv)

{

    unsigned int argc, i, ret = 0, buffer = 0;

    int c, opt_ind;

    for (argc = 0; argv[argc] != NULL; argc ++);

    for (c = 0, optind = 0, opt_ind = 0; c != -1;) {

        c = getopt_long(argc, argv, "hvmH:t:b:", long_options, &opt_ind);

        switch (c) {

        case 'h':

            help_cmd_cat(HELP_LONG);

            return CMD_SUCCESS;

        case 'v':

            printf("%s\n", CAT_VERSION);

            return CMD_SUCCESS;

        case 'H':

            printf(cat_oops);

            return CMD_FAILURE;

        case 't':

            printf(cat_oops);

            return CMD_FAILURE;

        case 'b':

            printf(cat_oops);

            break;

        case 'm':

            printf(cat_oops);

            return CMD_FAILURE;

        }

    }

    argc -= optind;

    if (argc < 1) {

        printf("%s - incorrect number of arguments. Try `%s --help'\n",

            cmdname, cmdname);

        return CMD_FAILURE;

    }

    i = optind;

    if (buffer <= 0)

        buffer = CAT_DEFAULT_BUFLEN;

    for (i = optind; argv[i] != NULL; i++)

        ret += cat_file(argv[i], buffer);

    if (ret)

        return CMD_FAILURE;

    else

        return CMD_SUCCESS;

}