source: mainline/uspace/app/bdsh/cmds/modules/ls/ls.c@ 72fda53

/*
 * Copyright (c) 2008 Tim Post
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <getopt.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <str.h>
#include <sort.h>

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

/* Various values that can be returned by ls_scope() */
#define LS_BOGUS 0
#define LS_FILE  1
#define LS_DIR   2

/** Structure to represent a directory entry.
 *
 * Useful to keep together important information
 * for sorting directory entries.
 */
struct dir_elem_t {
        char *name;
        struct stat s;
};

static const char *cmdname = "ls";

static struct option const long_options[] = {
        { "help", no_argument, 0, 'h' },
        { "unsort", no_argument, 0, 'u' },
        { 0, 0, 0, 0 }
};

/** Print an entry.
 *
 * 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.
 *
 * @param de            Directory element.
 */
static void ls_print(struct dir_elem_t *de)
{
        if (de->s.is_file)
                printf("%-40s\t%llu\n", de->name, (long long) de->s.size);
        else if (de->s.is_directory)
                printf("%-40s\t<dir>\n", de->name);
        else
                printf("%-40s\n", de->name);
}


/** Compare 2 directory elements.
 *
 * It compares 2 elements of a directory : a file is considered
 * as bigger than a directory, and if they have the same type,
 * they are compared alphabetically.
 *
 * @param a             Pointer to the structure of the first element.
 * @param b             Pointer to the structure of the second element.
 * @param arg           Pointer for an other and optionnal argument.
 *
 * @return              -1 if a < b, 1 otherwise.
 */
static int ls_cmp(void *a, void *b, void *arg)
{
        struct dir_elem_t *da = a;
        struct dir_elem_t *db = b;
        
        if ((da->s.is_directory && db->s.is_file) ||
            ((da->s.is_directory == db->s.is_directory) &&
            str_cmp(da->name, db->name) < 0))
                return -1;
        else
                return 1;
}

/** Scan a directory.
 *
 * Scan the content of a directory and print it.
 *
 * @param d             Name of the directory.
 * @param dirp  Directory stream.
 * @param sort  1 if the output must be sorted,
 *                              0 otherwise.
 */
static void ls_scan_dir(const char *d, DIR *dirp, int sort)
{
        int alloc_blocks = 20;
        int i;
        int nbdirs = 0;
        int rc;
        int len;
        char *buff;
        struct dir_elem_t *tmp;
        struct dir_elem_t *tosort;
        struct dirent *dp;
        
        if (!dirp)
                return;

        buff = (char *) malloc(PATH_MAX);
        if (!buff) {
                cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                return;
        }
        
        tosort = (struct dir_elem_t *) malloc(alloc_blocks * sizeof(*tosort));
        if (!tosort) {
                cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                free(buff);
                return;
        }
        
        while ((dp = readdir(dirp))) {
                if (nbdirs + 1 > alloc_blocks) {
                        alloc_blocks += alloc_blocks;
                        
                        tmp = (struct dir_elem_t *) realloc(tosort,
                            alloc_blocks * sizeof(struct dir_elem_t));
                        if (!tmp) {
                                cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                                goto out;
                        }
                        tosort = tmp;
                }
                
                /* fill the name field */
                tosort[nbdirs].name = (char *) malloc(str_size(dp->d_name) + 1);
                if (!tosort[nbdirs].name) {
                        cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                        goto out;
                }

                str_cpy(tosort[nbdirs].name, str_size(dp->d_name) + 1, dp->d_name);
                len = snprintf(buff, PATH_MAX - 1, "%s/%s", d, tosort[nbdirs].name);
                buff[len] = '\0';

                rc = stat(buff, &tosort[nbdirs++].s);
                if (rc != 0) {
                        printf("ls: skipping bogus node %s\n", buff);
                        printf("rc=%d\n", rc);
                        goto out;
                }
        }
        
        if (sort) {
                if (!qsort(&tosort[0], nbdirs, sizeof(struct dir_elem_t),
                    ls_cmp, NULL)) {
                        printf("Sorting error.\n");
                }
        }
        
        for (i = 0; i < nbdirs; i++)
                ls_print(&tosort[i]);
        
out:
        for(i = 0; i < nbdirs; i++)
                free(tosort[i].name);
        free(tosort);
        free(buff);
}

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(
                "Usage:  %s [options] [path]\n"
                "If not path is given, the current working directory is used.\n"
                "Options:\n"
                "  -h, --help       A short option summary\n"
                "  -u, --unsort     Do not sort directory entries\n",
                cmdname);
        }

        return;
}

int cmd_ls(char **argv)
{
        unsigned int argc;
        struct dir_elem_t de;
        DIR *dirp;
        int c, opt_ind;
        int sort = 1;

        argc = cli_count_args(argv);
        
        for (c = 0, optind = 0, opt_ind = 0; c != -1;) {
                c = getopt_long(argc, argv, "hu", long_options, &opt_ind);
                switch (c) {
                case 'h':
                        help_cmd_ls(HELP_LONG);
                        return CMD_SUCCESS;
                case 'u':
                        sort = 0;
                        break;
                }
        }
        
        argc -= optind;
        
        de.name = (char *) malloc(PATH_MAX);
        if (!de.name) {
                cli_error(CL_ENOMEM, "%s: ", cmdname);
                return CMD_FAILURE;
        }
        memset(de.name, 0, sizeof(PATH_MAX));
        
        if (argc == 0)
                getcwd(de.name, PATH_MAX);
        else
                str_cpy(de.name, PATH_MAX, argv[optind]);
        
        if (stat(de.name, &de.s)) {
                cli_error(CL_ENOENT, de.name);
                free(de.name);
                return CMD_FAILURE;
        }

        if (de.s.is_file) {
                ls_print(&de);
        } else {
                dirp = opendir(de.name);
                if (!dirp) {
                        /* May have been deleted between scoping it and opening it */
                        cli_error(CL_EFAIL, "Could not stat %s", de.name);
                        free(de.name);
                        return CMD_FAILURE;
                }
                ls_scan_dir(de.name, dirp, sort);
                closedir(dirp);
        }

        free(de.name);

        return CMD_SUCCESS;
}