숫자를 hex 코드로 변환
/* print input in hex */
void print_hex( int input ){
int var, i;
int len = 0;
char buf[255];
do{
var = input % 16;
input /= 16;
/* try to convert ascii code */
if( var<10 ) buf[len] = var+48;
else buf[len] = var+55;
len++;
}while( input>0 ); /* bigger than 16? then try again */
/* print reversely */
for ( i=len; i>0; i-- ) putchar( buf[i-1] );
putchar( '\n' );
}
int main( int argc, char** argv ){
int input;
printf( "input number: " );
scanf( " %d", &input );
/* print hex with printf */
printf( "%x\n", input );
/* print hex with my function */
print_hex( input );
return 0;
}