C library function - strtoul()

Description

The C library function unsigned long int strtoul(const char *str, char **endptr, int base) function converts the initial part of the string in str to an unsigned long int value according to the given base, which must be between 2 and 36 inclusive, or be the special value 0.

Declaration

Following is the declaration for strtoul() function.

unsigned long int strtoul(const char *str, char **endptr, int base)

Parameters

str − This is the string containing the representation of an unsigned integral number.
endptr − This is the reference to an object of type char*, whose value is set by the function to the next character in str after the numerical value.
base − This is the base, which must be between 2 and 36 inclusive, or be the special value 0.

Return Value

This function returns the converted integral number as a long int value. If no valid conversion could be performed, a zero value is returned.

Example

The following example shows the usage of strtoul() function.

Live Demo

#include <stdio.h>
#include <stdlib.h>

int main () {
   char str[30] = "2030300 This is test";
   char *ptr;
   long ret;

   ret = strtoul(str, &ptr, 10);
   printf("The number(unsigned long integer) is %lu\n", ret);
   printf("String part is |%s|", ptr);

   return(0);
}

Let us compile and run the above program that will produce the following result −

The number(unsigned long integer) is 2030300
String part is | This is test|

stdlib_h.htm