//Revision Lecture 17: Strings
//Sasha Vassar Week10

//Problem 2: Remove all characters in a string except for letters of the
//alphabet (read the string from standard input)

//Can you now read in from command line and do this?

#include <stdio.h>
#include <string.h>
#include <ctype.h>

#define MAX 1000

int main (int argc, char *argv[]) {
    /*char line[MAX];
    printf("Enter a string: ");
    fgets(line, MAX, stdin);
    // he9llo
    // hello
    */
    //isalpha (if it is betwee a and z or A and Z)
    int i = 0;
    //argc = how many arguments there are on the line
    // while (counter < argc) //counter = 1
    while (argv[1][i] != '\0') {
        int j = i;
        if (!isalpha(argv[1][j])){
        // get rid of it and shift everything back by one index
            // he9llo
            // line[2] = 9 
            // line[2] = l
            // line[3] = l
            // line[4] = o
            while (argv[1][j] != '\0') {
                argv[1][j] = argv[1][j + 1];
                j++;
            }
            argv[1][j]= '\0';   
        }
        i++;
    }
    
    printf("Output string is: %s\n", argv[1]);   
    return 0;
}