Getopt in C

main.c

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h>
#define PARAMLEN 2

void print_params(void)
{
        printf("Please enter the correct parameters...\n");
        printf("-f %3d Specify a folder to search...\n");
        printf("-e %3d Specify an extension type to search...\n");
}
int read_input(int argc,char **argv)
{
        int c;
        int fflag = 0;
        int eflag = 0;
        char *fvalue = NULL;
        char *evalue = NULL;

        while((c = getopt(argc,argv,"f:e:")) != -1)
        {
                switch(c)
                {
                        case 'f':
                                fflag =1;
                                fvalue = optarg;
                                break;
                        case 'e':
                                eflag =1;
                                evalue = optarg;
                                break;
                        case '?':

                                if(optopt == 'f')
                                {
                                        fprintf(stderr,"Option -%c requires an argument...\n",optopt);
                                }                               
                                
                                if(optopt == 'e')
                                {
                                        fprintf(stderr,"Option -%c requires an argument...\n",optopt);
                                }       
                                if (isprint (optopt))
                                {
                                        fprintf (stderr, "Unknown option `-%c'.\n", optopt);
                                        print_params();
                                }
                                else
                                {
                                        fprintf (stderr,"Unknown option character `\\x%x'.\n", optopt);                        
                                        print_params();
                                }       
                }
        }
        printf("fflag is %d with value of %s, eflag is %d with value of %s\n",fflag,fvalue,eflag,evalue);
        return 0;
}
int main(int argc,char **argv)
{
        read_input(argc,argv);
        
        return 0;
};