The strtoq and strtoll functions recognize strings in various
    formats, depending on the value of the base. Any leading white-
    space characters (as defined by isspace in <ctype.h>) in the
    given string are ignored. The functions recognize an optional
    plus or minus sign, then a sequence of digits or letters that may
    represent an integer constant according to the value of the base.
    The first unrecognized character ends the conversion.

    Leading zeros after the optional sign are ignored, and 0x or 0X
    is ignored if the base is 16.

    If base is 0, the sequence of characters is interpreted by
    the same rules used to interpret an integer constant: after
    the optional sign, a leading 0 indicates octal conversion, a
    leading 0x or 0X indicates hexadecimal conversion, and any other
    combination of leading characters indicates decimal conversion.

    The function call atoq (str) is equivalent to strtoq (str,
    (char**)NULL, 10).