CODEWITHSUNDEEP
ccommand-line-argumentsls
Steve
Steve

Reputation: 31

Iterating through options of ls program from the command line

I am writing a program that is a custom version of ls with some options. The options can be inputted as "-i" or as something like "-ilR". This portion of my code iterates through the command line arguments and sets a struct accordingly. Except if I run the program with "./myProgram -i Directory" it doesn't go into the test print I have set up.

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

struct optionArguments{
    bool argumenti;
    bool argumentl;
    bool argumentR; 
};

int main(int argc, char* argv[]){

    struct optionArguments options;
        options.argumenti = false;
        options.argumentl = false;
        options.argumentR = false;

   
    for(int i = 1; i<argc-2; i++){
        for(int j = 0; j<strlen(argv[i]); j++){
            char chr = argv[i][j];
            if(chr == 'i'){
                options.argumenti = true;
            }
            if(chr == "l"){
                options.argumentl = true;
            }
             if(chr == "R"){
                options.argumentR = true;
            }
        }
    }

    if(options.argumenti){
        printf("OPTION I\n");
    }
}

any help/advice is greatly appreciated

edit: I just put a test print inside of the second loop and it doesn't print anything at all so the second loop isn't even running.

Upvotes: 0

Views: 52

Answers (1)

Sourabh Choure
Sourabh Choure

Reputation: 733

It will be much simpler if you use getopt() function designed to handle command-line argument parsing.

Note: Since you have already included unistd library so using getopt which will be much wiser, otherwise, there are other implementations available as well like argp()

Here is a program which uses getopt from the POSIX C Library unistd

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

struct optionArguments{
    bool argumenti;
    bool argumentl;
    bool argumentR; 
};

int main(int argc, char* argv[]){

    struct optionArguments options;
        options.argumenti = false;
        options.argumentl = false;
        options.argumentR = false;

    int opt;
    while ((opt = getopt(argc, argv, "ilR")) != -1) {
        switch (opt) {
        case 'i': options.argumenti = true; break;
        case 'l': options.argumentl = true; break;
        case 'R': options.argumentR = true; break;
        default:
            fprintf(stderr, "Usage: %s [-ilR] \n", argv[0]);
            exit(EXIT_FAILURE);
        }
    }


    if(options.argumenti){
        printf("OPTION I\n");
    }
    if(options.argumentl){
        printf("OPTION l\n");
    }
    if(options.argumentR){
        printf("OPTION R\n");
    }
}

For other ways of implementation visit: Parsing command-line arguments in C?

Upvotes: 1

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