options.c

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>

#include "options.h"


struct CopymasterOptions ParseCopymasterOptions(int argc, char *argv[]) 
{
    extern int optind;
    extern char* optarg;

    struct CopymasterOptions cpm_options = {0};
    
    char c = 0, x = 0, *tok = 0;
    unsigned long long num = 0;
    long pos1 = -1, pos2 = -1;
    int i = 0;
    
    const char* usage_error_msg_format = "Usage: %s [OPTION]... SOURCE DEST\n(%s)\n";
    
    if (argc <= 0) {
        fprintf(stderr, usage_error_msg_format, "copymaster", "argc <= 0");
        exit(EXIT_FAILURE);
    }
    
    while (1)
    {
        // viac informacii o spracovani jednotlivych prepinacov 
        //  - pozri: man 3 getopt
        
        int option_index = 0;
        
        static struct option long_options[] = {
            { "fast",      no_argument,       0, 'f' },
            { "slow",      no_argument,       0, 's' }, 
            { "create",    required_argument, 0, 'c' },
            { "overwrite", no_argument,       0, 'o' }, 
            { "append",    no_argument,       0, 'a' }, 
            { "lseek",     required_argument, 0, 'l' }, 
            { "directory", required_argument, 0, 'D' }, 
            { "delete",    no_argument,       0, 'd' },
            { "chmod",     required_argument, 0, 'm' }, 
            { "inode",     required_argument, 0, 'i' },
            { "umask",     required_argument, 0, 'u' }, 
            { "link",      no_argument,       0, 'K' },
            { "truncate",  required_argument, 0, 't' },
            { "sparse",    no_argument,       0, 'S' },
            { 0,             0,               0,  0  },
        };
        c = getopt_long(argc, argv, "fsc:oal:Ddm:i:u:Kt:S", 
                        long_options, &option_index);
        if (c == -1)
            break; 
        
        switch (c)
        {
            case 'f':
                cpm_options.fast = 1;
                break;
            case 's': 
                cpm_options.slow = 1;
                break;
            case 'c': 
                cpm_options.create = 1;
                sscanf(optarg, "%o", &cpm_options.create_mode);
                break;
            case 'o': 
                cpm_options.overwrite = 1;
                break;
            case 'a': 
                cpm_options.append = 1;
                break;
            case 'l': 
                cpm_options.lseek = 1;
                i = sscanf(optarg, "%c,%ld,%ld,%llu", &x, &pos1, &pos2, &num);
                if (i < 4) {
                    fprintf(stderr, usage_error_msg_format, argv[0], "lseek - failed to scan 4 values");
                    exit(EXIT_FAILURE);
                }
                cpm_options.lseek_options.pos1 = (off_t)pos1;
                cpm_options.lseek_options.pos2 = (off_t)pos2;
                cpm_options.lseek_options.num = (size_t)num;
                switch (x) 
                {
                    case 'b':
                        cpm_options.lseek_options.x = SEEK_SET;
                        break;
                    case 'e':
                        cpm_options.lseek_options.x = SEEK_END;
                        break;
                    case 'c':
                        cpm_options.lseek_options.x = SEEK_CUR;
                        break;
                    default:
                        fprintf(stderr, usage_error_msg_format, argv[0], "lseek - invalid value of x");
                        exit(EXIT_FAILURE);
                        break;
                }
                break;
            case 'D': 
                cpm_options.directory = 1;
                break;
            case 'd': 
                cpm_options.delete_opt = 1;
                break;
            case 'm': 
                cpm_options.chmod = 1;
                sscanf(optarg, "%o", &cpm_options.chmod_mode);
                break;
            case 'i': 
                cpm_options.inode = 1;
                sscanf(optarg, "%lu", &cpm_options.inode_number);
                break;
            case 'u': 
                cpm_options.umask = 1;
                tok = strtok(optarg, ",");
                i = 0;
                while (tok != NULL && i < 9) {
                    if (strlen(tok) != 3) {
                        fprintf(stderr, usage_error_msg_format, argv[0], "umask - unexpected value of UTR option");
                        exit(EXIT_FAILURE);
                    }
                    strncpy(cpm_options.umask_options[i], tok, 3);
                    tok = strtok(NULL, ",");
                    ++i;
                }
                memset(cpm_options.umask_options[i], 0, 4);
                break;
            case 'K': 
                cpm_options.link = 1;
                break;
            case 't':
                cpm_options.truncate = 1;
                sscanf(optarg, "%ld", &pos1);
                cpm_options.truncate_size = (off_t)pos1; 
                break;
            case 'S': 
                cpm_options.sparse = 1;
                break;
            case '?':
            default:
                fprintf(stderr, usage_error_msg_format, argv[0]);
                exit(EXIT_FAILURE);
        }
    }
        
    // Kontrola ci boli zadanie parametre infile a outfile
    if (optind + 2 != argc) {
        fprintf(stderr, usage_error_msg_format, argv[0], "infile or outfile is missing");
        exit(EXIT_FAILURE);
    }
    
    cpm_options.infile = argv[optind];
    cpm_options.outfile = argv[optind + 1];
    
    return cpm_options;
}