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

int is_empty(const char *s)
{
    while ( isspace(*s) && ++s );
    return !*s;
}


int main(void)
{
	char *line0 = "";
	char *line1 = "ads";
	char *line2 = "\tds";
	char *line3 = "\tds\r";
	char *line4 = "\t\v\n";
	
	printf("is_empty(%s) -> %d\n", line0, is_empty(line0));
	printf("is_empty(%s) -> %d\n", line1, is_empty(line1));
	printf("is_empty(%s) -> %d\n", line2, is_empty(line2));
	printf("is_empty(%s) -> %d\n", line3, is_empty(line3));
	printf("is_empty(%s) -> %d\n", line4, is_empty(line4));

	return 0;
}