compressor.c

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

void compress(){

    int seen_char = getchar();
    int next_char;
    int repeat_counter = 1;

    if (seen_char == EOF) return;

    while ((next_char = getchar()) != EOF)
    {
        if (next_char == seen_char)
        {
            repeat_counter++; 
            if (repeat_counter==255)
            {
                putchar(seen_char);
                putchar(repeat_counter);
                repeat_counter=0; 
            } 
        }
        else
        {
            putchar(seen_char);
            putchar(repeat_counter);
            repeat_counter=1; 
            seen_char = next_char;
        }
    }
    putchar(seen_char);
    putchar(repeat_counter);
}
void decompress(){
    while (1)
    {
        int c = getchar();
        if(c == EOF) 
            break;
        int count = getchar();
        if(count == EOF) 
            break;

        for (int i = 0; i < count; i++)
        {
            putchar(c);
        }
    }
}

int main(int argc, char *argv[]){
    if (argc != 2)
    {
        printf("Usages: %s [compress|decompress]\n", argv[0]);
        exit(-2);
    }


    if (!strcmp(argv[1] , "compress")) //value in a condition normally must be true to enter the condition
    {
        compress();
    }
    else if (!strcmp(argv[1] , "decompress"))
    {
        decompress();
    }
    else 
    {
        printf("Usages: %s [compress|decompress]\n", argv[0]);
        exit(-2);
    }
}