strtoq
converts the string nptr
to a quadt value. The conversion is done according to the given base, which
shall be between 2 and 36 inclusive,
or be the special value 0.
nptr may begin with an arbitrary amount of white
space (as determined by isspace
(3)), followed by a
single optional + or - sign character. If
base is 0 or 16,
the string may then include a 0x prefix, and the number will
be read in base 16; otherwise, a 0 base is taken as
10 (decimal), unless the next character is 0, in which
case it is taken as 8 (octal).
The remainder of the string is converted to a long value in the obvious manner, stopping at the first character which is not a valid digit in the given base. (In bases above 10, the letter A in either upper or lower case represents 10, B represents 11, and so forth, with Z representing 35.)