#include <stdio.h>

int main(int argc, char **argv)
{   
    FILE *f;
    if(argc>1){
	char buf[256];
	sprintf(buf,"%s/%s",getenv("PWD"),argv[1]);
	f=fopen(buf,"r");
    }
    else f=stdin;

    setvbuf(stdin,NULL,_IONBF,0);
    setvbuf(stdout,NULL,_IONBF,0);

    char c;

    printf("-- reading from file byte by byte --\n\n");

    while(fread(&c,1,1,f))
    {
	printf("%c",c);
    }

    printf("\n-- no more data on this file --\n");

    return 0;
}