strtol function

strtol will convert a string to a long integer. An important feature of this function is the ability to accept data in various number bases and convert to decimal. If you are just working with decimal numbers, atoi is probably an easer function to use.


Library:   stdlib.h

Prototype: long int strtol(const char *sptr, char **endptr, int base);

Syntax:	   char     String[]="ff";		/* string to convert	*/
	   int      Base=16;			/* Base 16		*/
           long int Ans;			/* Result		*/

           Ans = strtol(String, NULL, Base);

Notes

The second argument (char **endptr) seems to be a waste of space! If it is set to NULL, STRTOL seems to work its way down the string until it finds an invalid character and then stops. All valid chars read are then converted if the string starts with an invalid character the function returns ZERO (0).

The Third argument (base) can have a value of 0 or 2-32.

0 - strtol will attempt to pick the base. Only Dec, Oct Hex supported.
2-31 - The base to use.

Examples:

Example program.

strtol function

Notes

Examples:

See also: