AAE-CNAS-Labs/Topic-1/main.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>

#define BUFFER_SIZE 8

enum ERROR{NO_ARGUMENTS, WRONG_ARGUMENT};

int print_error_message(enum ERROR error_type) {
    if (error_type == NO_ARGUMENTS) {
        fprintf(stderr,"cp: missing file operand\n"); // TODO: Maybe replace "cp" with argv[0]?
        fprintf(stderr,"Try cp --help for more information.\n");
        return 0;
    } else if (error_type == WRONG_ARGUMENT) {
        fprintf(stderr, "cp: unrecognized option\n");
        fprintf(stderr,"Try cp --help for more information.\n");
    }
    return 0;
}

int print_help() {
    printf("HELP\n");
    return 0;
}

int cp(char *argv[]){
    int old, new;
    old = open(argv[1], O_RDONLY);
    new = open(argv[2], O_CREAT | O_WRONLY);
    char buffer[BUFFER_SIZE];
    int read_bytes;

    while ((read_bytes = read(old, buffer, sizeof(buffer))) > 0) {
        write(new, buffer, read_bytes);
    }

    struct stat mod_bits;

    stat(argv[1], &mod_bits);
    chmod(argv[2], mod_bits.st_mode);

    close(old);
    close(new);

    return 0;
}

int main(int argc, char *argv[]) {
    if (argc == 1) {
        print_error_message(NO_ARGUMENTS);
        return 1;
    }
    if (argc == 2) {
        if (strcmp(argv[1], "--help") == 0) {
            print_help();
            return 0;
        } else {
            print_error_message(WRONG_ARGUMENT);
            return 2;
        }
    }
    if (argc == 3) {
        if (cp(argv) > 0) return 1;
    }
    return 0;
}