Header File 

stdlib.h  

Category 

Conversion Routines, Math Routines 

Prototype 

char *ultoa(unsigned long value, char *string, int radix); 

wchar_t *_ultow(unsigned long value, wchar_t *string, int radix); 

Description 

Converts an unsigned long to a string. 

ultoa converts value to a null-terminated string and stores the result in string. value is an unsigned long. 

radix specifies the base to be used in converting value; it must be between 2 and 36, inclusive. ultoa performs no overflow checking, and if value is negative and radix equals 10, it does not set the minus sign.

ultoa returns string. 

Example  

#include <stdlib.h>
#include <stdio.h>
int main( void )
{
   unsigned long lnumber = 3123456789L;
   char string[25];
   ultoa(lnumber,string,10);
   printf("string = %s  unsigned long = %lu\n",string,lnumber);
   return 0;
}

Portability