cp.c

/* 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 <str.h>
#include <fcntl.h>
#include "config.h"
#include "util.h"
#include "errors.h"
#include "entry.h"
#include "cp.h"
#include "cmds.h"

#define CP_VERSION "0.0.1"
#define CP_DEFAULT_BUFLEN  1024

static const char *cmdname = "cp";

static struct option const long_options[] = {
        { "buffer", required_argument, 0, 'b' },
        { "force", no_argument, 0, 'f' },
        { "recursive", no_argument, 0, 'r' },
        { "help", no_argument, 0, 'h' },
        { "version", no_argument, 0, 'v' },
        { "verbose", no_argument, 0, 'V' },
        { 0, 0, 0, 0 }
};

static int strtoint(const char *s1)
{
        long t1;

        if (-1 == (t1 = strtol(s1, (char **) NULL, 10)))
                return -1;

        if (t1 <= 0)
                return -1;

        return (int) t1;
}

static int64_t copy_file(const char *src, const char *dest,
        size_t blen, int vb)
{
        int fd1, fd2, bytes = 0;
        off64_t total = 0;
        int64_t copied = 0;
        char *buff = NULL;

        if (vb)
                printf("Copying %s to %s\n", src, dest);

        if (-1 == (fd1 = open(src, O_RDONLY))) {
                printf("Unable to open source file %s\n", src);
                return -1;
        }

        if (-1 == (fd2 = open(dest, O_CREAT))) {
                printf("Unable to open destination file %s\n", dest);
                close(fd1);
                return -1;
        }

        total = lseek(fd1, 0, SEEK_END);

        if (vb)
                printf("%" PRIu64 " bytes to copy\n", total);

        lseek(fd1, 0, SEEK_SET);

        if (NULL == (buff = (char *) malloc(blen))) {
                printf("Unable to allocate enough memory to read %s\n",
                    src);
                copied = -1;
                goto out;
        }

        for (;;) {
                ssize_t res;
                size_t written = 0;

                bytes = read(fd1, buff, blen);
                if (bytes <= 0)
                        break;
                copied += bytes;
                res = bytes;
                do {
                        /*
                         * Theoretically, it may not be enough to call write()
                         * only once. Also the previous read() may have
                         * returned less data than requested.
                         */
                        bytes = write(fd2, buff + written, res);
                        if (bytes < 0)
                                goto err;
                        written += bytes;
                        res -= bytes;
                } while (res > 0);

                /* TODO: re-insert assert() once this is stand alone,
                 * removed as abort() exits the entire shell
                 */
                if (res != 0) {
                        printf("\n%zd more bytes than actually exist were copied\n", res);
                        goto err;
                }
        }

        if (bytes < 0) {
err:
                printf("\nError copying %s, (%d)\n", src, bytes);
                copied = bytes;
        }

out:
        close(fd1);
        close(fd2);
        if (buff)
                free(buff);
        return copied;
}

void help_cmd_cp(unsigned int level)
{
        static char helpfmt[] =
            "Usage:  %s [options] <source> <dest>\n"
            "Options: (* indicates not yet implemented)\n"
            "  -h, --help       A short option summary\n"
            "  -v, --version    Print version information and exit\n"
            "* -V, --verbose    Be annoyingly noisy about what's being done\n"
            "* -f, --force      Do not complain when <dest> exists\n"
            "* -r, --recursive  Copy entire directories\n"
            "  -b, --buffer ## Set the read buffer size to ##\n"
            "Currently, %s is under development, some options may not work.\n";
        if (level == HELP_SHORT) {
                printf("`%s' copies files and directories\n", cmdname);
        } else {
                help_cmd_cp(HELP_SHORT);
                printf(helpfmt, cmdname, cmdname);
        }

        return;
}

int cmd_cp(char **argv)
{
        unsigned int argc, verbose = 0;
        int buffer = 0;
        int c, opt_ind;
        int64_t ret;

        argc = cli_count_args(argv);

        for (c = 0, optind = 0, opt_ind = 0; c != -1;) {
                c = getopt_long(argc, argv, "hvVfrb:", long_options, &opt_ind);
                switch (c) { 
                case 'h':
                        help_cmd_cp(1);
                        return CMD_SUCCESS;
                case 'v':
                        printf("%s\n", CP_VERSION);
                        return CMD_SUCCESS;
                case 'V':
                        verbose = 1;
                        break;
                case 'f':
                        break;
                case 'r':
                        break;
                case 'b':
                        if (-1 == (buffer = strtoint(optarg))) {
                                printf("%s: Invalid buffer specification, "
                                    "(should be a number greater than zero)\n",
                                    cmdname);
                                return CMD_FAILURE;
                        }
                        if (verbose)
                                printf("Buffer = %d\n", buffer);
                        break;
                }
        }

        if (buffer == 0)
                buffer = CP_DEFAULT_BUFLEN;

        argc -= optind;

        if (argc != 2) {
                printf("%s: invalid number of arguments. Try %s --help\n",
                    cmdname, cmdname);
                return CMD_FAILURE;
        }

        ret = copy_file(argv[optind], argv[optind + 1], buffer, verbose);

        if (verbose)
                printf("%" PRId64 " bytes copied\n", ret);

        if (ret >= 0)
                return CMD_SUCCESS;
        else
                return CMD_FAILURE;
}

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