source: mainline/uspace/app/bdsh/cmds/modules/ls/ls.c@ beb6b3d

/* 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 <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 "ls.h"
#include "cmds.h"

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 }
};

/** Compare 2 directory elements.
 *
 * It compares 2 elements of a directory : a file is considered
 * as lower 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)
{
        int a_isdir = (*((struct dir_elem_t *)a)).isdir;
        char * a_name = (*((struct dir_elem_t *)a)).name;
        
        int b_isdir = (*((struct dir_elem_t *)b)).isdir;
        char * b_name = (*((struct dir_elem_t *)b)).name;
        
        if ((!a_isdir && b_isdir)
                || (((!b_isdir && !a_isdir) || (b_isdir && a_isdir))
                && str_cmp(a_name, b_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.
 */
static void ls_scan_dir(const char *d, DIR *dirp, int sort)
{
        int alloc_blocks = 20;
        int i = 0;
        int nbdirs = 0;
        int rc = 0;
        char * buff = NULL;
        struct dir_elem_t * tmp = NULL;
        struct dir_elem_t * tosort = NULL;
        struct dirent * dp = NULL;
        struct stat s;
        
        if (! dirp)
                return;

        buff = (char *)malloc(PATH_MAX);
        if (NULL == buff) {
                cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                return;
        }
        memset(buff, 0, sizeof(buff));
        
        if (!sort) {
                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);
                        ls_print(dp->d_name, buff);
                }

                free(buff);

                return;
        }
        
        tosort = (struct dir_elem_t *)malloc(alloc_blocks*sizeof(struct dir_elem_t));
        if (NULL == tosort) {
                cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                free(buff);
                return;
        }
        memset(tosort, 0, sizeof(tosort));
        
        while ((dp = readdir(dirp))) {
                nbdirs++;
                
                if (nbdirs > alloc_blocks) {
                        alloc_blocks += alloc_blocks;
                        
                        tmp = (struct dir_elem_t *)realloc(tosort,
                                        alloc_blocks*sizeof(struct dir_elem_t));
                        if (NULL == tmp) {
                                cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                                for(i=0;i<(nbdirs-1);i++) {
                                        free(tosort[i].name);
                                }
                                free(tosort);
                                free(buff);
                                return;
                        }
                        
                        tosort = tmp;
                }
                
                // fill the name field
                tosort[nbdirs-1].name = (char *)malloc(str_length(dp->d_name)+1);
                if (NULL == tosort[nbdirs-1].name) {
                        cli_error(CL_ENOMEM, "ls: failed to scan %s", d);
                        for(i=0;i<(nbdirs-1);i++) {
                                free(tosort[i].name);
                        }
                        free(tosort);
                        free(buff);
                        return;
                }
                
                memset(tosort[nbdirs-1].name, 0, str_length(dp->d_name)+1);
                str_cpy(tosort[nbdirs-1].name, str_length(dp->d_name)+1, dp->d_name);
                
                // fill the isdir field
                memset(buff, 0, sizeof(buff));
                snprintf(buff, PATH_MAX - 1, "%s/%s", d, tosort[nbdirs-1].name);
                
                rc = stat(buff, &s);
                if (rc != 0) {
                        printf("ls: skipping bogus node %s\n", buff);
                        printf("rc=%d\n", rc);
                        for(i=0;i<nbdirs;i++) {
                                free(tosort[i].name);
                        }
                        free(tosort);
                        free(buff);
                        return;
                }
                
                tosort[nbdirs-1].isdir = s.is_directory ? 1 : 0;
        }
        
        if (!qsort(&tosort[0], nbdirs, sizeof(struct dir_elem_t), ls_cmp, NULL)) {
                printf("Sorting error.\n");
        }
        
        for(i=0;i<nbdirs;i++) {
                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, tosort[i].name);
                ls_print(tosort[i].name, buff);
                free(tosort[i].name);
        }
        
        free(tosort);
        free(buff);

        return;
}

/** 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 name          Name of the entry.
 * @param pathname      Path of the entry.
 */
static void ls_print(const char *name, const char *pathname)
{
        struct stat s;
        int rc;

        rc = stat(pathname, &s);
        if (rc != 0) {
                /* Odd chance it was deleted from the time readdir() found it */
                printf("ls: skipping bogus node %s\n", pathname);
                printf("rc=%d\n", rc);
                return;
        }
        
        if (s.is_file)
                printf("%-40s\t%llu\n", name, (long long) s.size);
        else if (s.is_directory)
                printf("%-40s\t<dir>\n", name);
        else
                printf("%-40s\n", name);

        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(
                "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 stat s;
        char *buff;
        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;
                }
        }
        
        int dir = (int)argc > optind ? (int)argc-1 : optind-1;
        argc -= (optind-1);
        
        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
                str_cpy(buff, PATH_MAX, argv[dir]);
        
        if (stat(buff, &s)) {
                cli_error(CL_ENOENT, buff);
                free(buff);
                return CMD_FAILURE;
        }

        if (s.is_file) {
                ls_print(buff, buff);
        } else {
                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, sort);
                closedir(dirp);
        }

        free(buff);

        return CMD_SUCCESS;
}