main.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <getopt.h>
#include "main.h"
#include "ext4_undelete.h"

#define GETOPT_ARGS "hi:n:o:s"

static void print_help() {
    printf("\nUsage: ./ext4_undelete device -i ino [OPTIONS]");
    printf("\n\nOptions:");
    printf("\n\t-h: print this help");
    printf("\n\t-i ino: specifies inode number, which holds info about file which should be undeleted");
    printf("\n\t-n original-filename: original filename of deleted file. Can be used only in case, that parent directory of deleted file exists.");
    printf("\n\t-o filename: filename of undeleted file. Default is %s", DEFAULT_FILENAME);
    printf("\n\t-s: strip trailing zeros in last block. By default, this option is off");
    printf("\n");
}

static struct options parse_options(int argc, char ** argv) {
    int c;
    int index;

    struct options opts = {
        .state = 0,
        .ino = 0,
        .output_name = DEFAULT_FILENAME,
        .original_name = NULL,
        .device = NULL,
        .strip = false
    };
    
    while ((c = getopt(argc, argv, GETOPT_ARGS)) != -1) {
        switch (c) {
            case 'h':
                print_help();
                opts.state = -1;
                return opts;
            case 'i':          
                opts.ino = strtoul(optarg, NULL, 0);
                break;
            case 'o':
                opts.output_name = optarg;
                break;
            case 'n':
                opts.original_name = optarg;
                break;
            case 's':
                opts.strip = true;
                break;
            case '?':
                if (optopt == 'c')
                    fprintf(stderr, "Option -%c requires an argument.\n", optopt);
                else if (isprint(optopt))
                    fprintf(stderr, "Unknown option `-%c'.\n", optopt);
                else
                    fprintf(stderr, "Unknown option character `\\x%x'.\n", optopt);
                
                print_help();
                opts.state = -1;
                    
                return opts;
            default:
                print_help();
                opts.state = -1;
                return opts;
        }
    }

    argc -= optind;
    argv += optind;

    // process non option params
    for (index = 0; index < argc; index++) {
        if (index == 0) {
            opts.device = argv[index];
        }
    }

    // device param is required
    if (opts.device == NULL) {
        opts.state = -1;
        fprintf(stderr, "Missing device param!\n");
        print_help();
        return opts;
    }

    // inode offset is required
    if ((opts.ino == 0) && (opts.original_name == NULL)) {
        opts.state = -1;
        fprintf(stderr, "inode number or original filename param is "
                "required!\n");
        print_help();
        return opts;
    }

    // if inode number and original filename is specified at the same time
    if ((opts.ino != 0) && (opts.original_name != NULL)){
        opts.state = -1;
        fprintf(stderr, "you can't specify inode number and original filename "
                "at the same time!\n");
        print_help();
        return opts;
    }

    return opts;
}

int main(int argc, char ** argv) {
    struct options opts;

    opts = parse_options(argc, argv);
    if (opts.state < 0)
        return EXIT_FAILURE;
    
    if (undelete_file(opts.device, opts.original_name, opts.ino, opts.output_name, opts.strip) < 0) {
        return EXIT_FAILURE;
    }

    return EXIT_SUCCESS;
}