２進、８進、１６進まとめて表示

#include <stdio.h>
char *get_binary_expression( int n )
{
static char buf[ 1024 ];
char *end = buf + sizeof(buf) - 1;
*end-- = '\0';
while ( buf != end ) {
*end = '0' + n%2;
if ( n < 2 ) break;
n /= 2; --end;
}
return end;
}
static void print_result( int n )
{
printf( " %d\t%s\t%o\t%X\n", n, get_binary_expression( n ), n, n );
}
int main( void )
{
char buf[32];
int a;
while (1) {
fgets( buf, sizeof(buf), stdin );
if ( buf[0] == 'q' ) break;
sscanf( buf, "%d", &a );
print_result( a );
}
}