UniStrtol converts the initial portion of the string pointed to by nptr to long int representation. First, it decomposes the input string into three parts:

• An initial, possibly empty, sequence of white-space characters (as indicated by the space attribute).

• A subject sequence, resembling an integer, that is represented in the radix and determined by the value of base.

• A final string of one or more unrecognized characters, including the ending null character of the input string.

Then, it attempts to convert the subject sequence to an unsigned integer, and returns the result in the area pointed to by liResult. A pointer to the final string is stored in the object pointed to by endptr, provided that endptr is not a null pointer.

• If base is between 2 and 36, the letters a (or A) to z (or Z), inclusive, are ascribed the values 10 to 35. Only letters whose ascribed value is less than base are permitted.

• If base is set to 0, the expected form of the subject sequence is a decimal, octal, or hexadecimal constant.

  Decimal constants begin with a nonzero digit. Octal constants begin with 0. Hexadecimal constants begin with 0x or 0X.