main

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

char *toUpper(char *str){
    int hossz = strlen(str);
    int i;
    for (i = 0; i < hossz; i++)
    {
        if (str[i] >= 'a' && str[i] <= 'z')
        {
        str[i] - 'a' + 'A';
        }
     return str;
}
}

void vizsgalat(const int argc, char *argv){
    if (argc < 1 )
    {
        fprintf(errorfile.txt, "No argument.");
        return 1;
    }
    else{
        for (int i = 1; i < argc; ++i)
        {
            printf("%s\n",toUpper(argv[i]));
        }
        return 0;
    }
}


int main(int argc, char **argv)
{
     for (int i = 1; i < argc; ++i)
    {
        if(vizsgalat(argv[i])==0)
        {
        printf("%s\n",toUpper(argv[i]));
        }
        else
        {
            exit;
        }

    }
}