rm.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 <fcntl.h>
#include <dirent.h>
#include <getopt.h>
#include <mem.h>
#include <str.h>

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

static const char *cmdname = "rm";
#define RM_VERSION "0.0.1"

static rm_job_t rm;

static struct option const long_options[] = {
        { "help", no_argument, 0, 'h' },
        { "version", no_argument, 0, 'v' },
        { "recursive", no_argument, 0, 'r' },
        { "force", no_argument, 0, 'f' },
        { "safe", no_argument, 0, 's' },
        { 0, 0, 0, 0 }
};

static unsigned int rm_start(rm_job_t *rm)
{
        rm->recursive = 0;
        rm->force = 0;
        rm->safe = 0;

        /* Make sure we can allocate enough memory to store
         * what is needed in the job structure */
        if (NULL == (rm->nwd = (char *) malloc(PATH_MAX)))
                return 0;
        memset(rm->nwd, 0, sizeof(rm->nwd));

        if (NULL == (rm->owd = (char *) malloc(PATH_MAX)))
                return 0;
        memset(rm->owd, 0, sizeof(rm->owd));

        if (NULL == (rm->cwd = (char *) malloc(PATH_MAX)))
                return 0;
        memset(rm->cwd, 0, sizeof(rm->cwd));

        chdir(".");

        if (NULL == (getcwd(rm->owd, PATH_MAX)))
                return 0;

        return 1;
}

static void rm_end(rm_job_t *rm)
{
        if (NULL != rm->nwd)
                free(rm->nwd);

        if (NULL != rm->owd)
                free(rm->owd);

        if (NULL != rm->cwd)
                free(rm->cwd);

        return;
}

static unsigned int rm_recursive_not_empty_dirs(const char *path)
{
        DIR *dirp;
        struct dirent *dp;
        char buff[PATH_MAX];
        unsigned int scope;
        unsigned int ret = 0;

        dirp = opendir(path);
        if (!dirp) {
                /* May have been deleted between scoping it and opening it */
                cli_error(CL_EFAIL, "Could not open %s", path);
                return ret;
        }

        memset(buff, 0, sizeof(buff));
        while ((dp = readdir(dirp))) {
                snprintf(buff, PATH_MAX - 1, "%s/%s", path, dp->d_name);
                scope = rm_scope(buff);
                switch (scope) {
                case RM_BOGUS:
                        break;
                case RM_FILE:
                        ret += rm_single(buff);
                        break;
                case RM_DIR:
                        ret += rm_recursive(buff);
                        break;
                }
        }
        
        return ret;
}

static unsigned int rm_recursive(const char *path)
{
        int rc;
        unsigned int ret = 0;

        /* First see if it will just go away */
        rc = rmdir(path);
        if (rc == 0)
                return 0;

        /* Its not empty, recursively scan it */
        ret = rm_recursive_not_empty_dirs(path);

        /* Delete directory */
        rc = rmdir(path);
        if (rc == 0)
                return ret;

        cli_error(CL_ENOTSUP, "Can not remove %s", path);

        return ret + 1;
}

static unsigned int rm_single(const char *path)
{
        if (unlink(path)) {
                cli_error(CL_EFAIL, "rm: could not remove file %s", path);
                return 1;
        }
        return 0;
}

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

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

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

        return RM_BOGUS;
}

/* Dispays help for rm in various levels */
void help_cmd_rm(unsigned int level)
{
        if (level == HELP_SHORT) {
                printf("`%s' removes files and directories.\n", cmdname);
        } else {
                help_cmd_rm(HELP_SHORT);
                printf(
                "Usage:  %s [options] <path>\n"
                "Options:\n"
                "  -h, --help       A short option summary\n"
                "  -v, --version    Print version information and exit\n"
                "  -r, --recursive  Recursively remove sub directories\n"
                "  -f, --force      Do not prompt prior to removing files\n"
                "  -s, --safe       Stop if directories change during removal\n\n"
                "Currently, %s is under development, some options don't work.\n",
                cmdname, cmdname);
        }
        return;
}

/* Main entry point for rm, accepts an array of arguments */
int cmd_rm(char **argv)
{
        unsigned int argc;
        unsigned int i, scope, ret = 0;
        int c, opt_ind;
        size_t len;
        char *buff = NULL;

        argc = cli_count_args(argv);

        if (argc < 2) {
                cli_error(CL_EFAIL,
                        "%s: insufficient arguments. Try %s --help", cmdname, cmdname);
                return CMD_FAILURE;
        }

        if (!rm_start(&rm)) {
                cli_error(CL_ENOMEM, "%s: could not initialize", cmdname);
                rm_end(&rm);
                return CMD_FAILURE;
        }

        for (c = 0, optind = 0, opt_ind = 0; c != -1;) {
                c = getopt_long(argc, argv, "hvrfs", long_options, &opt_ind);
                switch (c) {
                case 'h':
                        help_cmd_rm(HELP_LONG);
                        return CMD_SUCCESS;
                case 'v':
                        printf("%s\n", RM_VERSION);
                        return CMD_SUCCESS;
                case 'r':
                        rm.recursive = 1;
                        break;
                case 'f':
                        rm.force = 1;
                        break;
                case 's':
                        rm.safe = 1;
                        break;
                }
        }

        if ((unsigned) optind == argc) {
                cli_error(CL_EFAIL,
                        "%s: insufficient arguments. Try %s --help", cmdname, cmdname);
                rm_end(&rm);
                return CMD_FAILURE;
        }

        i = optind;
        while (NULL != argv[i]) {
                len = str_size(argv[i]) + 2;
                buff = (char *) realloc(buff, len);
                if (buff == NULL) {
                        printf("rm: out of memory\n");
                        ret = 1;
                        break;
                }
                memset(buff, 0, sizeof(buff));
                snprintf(buff, len, "%s", argv[i]);

                scope = rm_scope(buff);
                switch (scope) {
                case RM_BOGUS: /* FIXME */
                case RM_FILE:
                        ret += rm_single(buff);
                        break;
                case RM_DIR:
                        if (! rm.recursive) {
                                printf("%s is a directory, use -r to remove it.\n", buff);
                                ret ++;
                        } else {
                                ret += rm_recursive(buff);
                        }
                        break;
                }
                i++;
        }

        if (NULL != buff)
                free(buff);

        rm_end(&rm);

        if (ret)
                return CMD_FAILURE;
        else
                return CMD_SUCCESS;
}

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