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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.
 */

/* NOTE:
 * This is a bit of an ugly hack, working around the absence of fstat / etc.
 * As more stuff is completed and exposed in libc, this will improve */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>

#include "errors.h"
#include "config.h"
#include "util.h"
#include "entry.h"
#include "ls.h"
#include "cmds.h"

static char *cmdname = "ls";

static inline off_t flen(const char *f)
{
    int fd;
    off_t size;

    fd = open(f, O_RDONLY);
    if (fd == -1)
        return 0;

    size = lseek(fd, 0, SEEK_END);
    close(fd);

    if (size < 0)
        size = 0;

    return size;
}

static unsigned int ls_scope(const char *path)
{
    int fd;
    DIR *dirp;

    dirp = opendir(path);
    if (dirp) {
        closedir(dirp);
        return LS_DIR;
    }

    fd = open(path, O_RDONLY);
    if (fd > 0) {
        close(fd);
        return LS_FILE;
    }

    return LS_BOGUS;
}

static void ls_scan_dir(const char *d, DIR *dirp)
{
    struct dirent *dp;
    unsigned int scope;
    char *buff;

    if (! dirp)
        return;

    buff = (char *)malloc(PATH_MAX);
    if (NULL == buff) {
        cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
        return;
    }

    while ((dp = readdir(dirp))) {
        memset(buff, 0, sizeof(buff));
        /* Don't worry if inserting a double slash, this will be fixed by
         * absolutize() later with subsequent calls to open() or readdir() */
        snprintf(buff, PATH_MAX - 1, "%s/%s", d, dp->d_name);
        scope = ls_scope(buff);
        switch (scope) {
        case LS_DIR:
            ls_print_dir(dp->d_name);
            break;
        case LS_FILE:
            ls_print_file(dp->d_name);
            break;
        case LS_BOGUS:
            /* Odd chance it was deleted from the time readdir() found
             * it and the time that it was scoped */
            printf("ls: skipping bogus node %s\n", dp->d_name);
            break;
        }
    }

    free(buff);

    return;
}

/* ls_print_* currently does nothing more than print the entry.
 * in the future, we will likely pass the absolute path, and
 * some sort of ls_options structure that controls how each
 * entry is printed and what is printed about it.
 *
 * Now we just print basic DOS style lists */

static void ls_print_dir(const char *d)
{
    printf("%-40s\t<dir>\n", d);

    return;
}

static void ls_print_file(const char *f)
{
    printf("%-40s\t%llu\n", f, (long long) flen(f));

    return;
}

void help_cmd_ls(unsigned int level)
{
    if (level == HELP_SHORT) {
        printf("`%s' lists files and directories.\n", cmdname);
    } else {
        help_cmd_ls(HELP_SHORT);
        printf("  `%s' [path], if no path is given the current "
                "working directory is used.\n", cmdname);
    }

    return;
}

int cmd_ls(char **argv)
{
    unsigned int argc;
    unsigned int scope;
    char *buff;
    DIR *dirp;

    argc = cli_count_args(argv);

    buff = (char *) malloc(PATH_MAX);
    if (NULL == buff) {
        cli_error(CL_ENOMEM, "%s: ", cmdname);
        return CMD_FAILURE;
    }
    memset(buff, 0, sizeof(buff));

    if (argc == 1)
        getcwd(buff, PATH_MAX);
    else
        strncpy(buff, argv[1], PATH_MAX);

    scope = ls_scope(buff);

    switch (scope) {
    case LS_BOGUS:
        cli_error(CL_ENOENT, buff);
        free(buff);
        return CMD_FAILURE;
    case LS_FILE:
        ls_print_file(buff);
        break;
    case LS_DIR:
        dirp = opendir(buff);
        if (! dirp) {
            /* May have been deleted between scoping it and opening it */
            cli_error(CL_EFAIL, "Could not stat %s", buff);
            free(buff);
            return CMD_FAILURE;
        }
        ls_scan_dir(buff, dirp);
        closedir(dirp);
        break;
    }

    free(buff);

    return CMD_SUCCESS;
}