A poorly written OS for the x86 arch. (WIP)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
eOS/lib/conv.c

37 lines
767 B

#include "conv.h"
#include "../drivers/vga.h"
char* itoa( int value, char * str, int base ) {
char* rc;
char* ptr;
char* low;
// Check for supported base.
if ( base < 2 || base > 36 ) {
*str = '\0';
return str;
}
rc = ptr = str;
if ( value < 0 && base == 10 ) // sign
*ptr++ = '-';
// Remember where the numbers start.
low = ptr;
// The actual conversion.
do {
// Modulo is negative for negative value. This trick makes abs() unnecessary.
*ptr++ = "zyxwvutsrqponmlkjihgfedcba9876543210123456789abcdefghijklmnopqrstuvwxyz"[35 + value % base];
value /= base;
} while ( value );
// Terminating the string.
*ptr-- = '\0';
// Invert the numbers.
while ( low < ptr ) {
char tmp = *low;
*low++ = *ptr;
*ptr-- = tmp;
}
return rc;
}