Tcl_GetInt(interp, src, intPtr)
Tcl_GetDouble(interp, src, doublePtr)
Tcl_GetBoolean(interp, src, boolPtr)
These procedures convert from strings to integers or double-precision
floating-point values or booleans (represented as 0- or 1-valued
integers). Each of the procedures takes a src argument,
converts it to an internal form of a particular type, and stores
the converted value at the location indicated by the procedures
third argument. If all goes well, each of the procedures returns
TCL_OK. If src does not have the proper syntax for the
desired type then TCL_ERROR is returned, an error message is left
in the interpreters result, and nothing is stored at *intPtr
or *doublePtr or *boolPtr.
Tcl_GetInt expects src to consist of a collection
of integer digits, optionally signed and optionally preceded by
white space. If the first two characters of src
after the optional white space and sign are
then src is expected to be in hexadecimal form; otherwise,
if the first such character is
is expected to be in octal form; otherwise, src is
expected to be in decimal form.
Tcl_GetDouble expects src to consist of a floating-point
number, which is: white space; a sign; a sequence of digits; a
decimal point; a sequence of digits; the letter
a signed decimal exponent; and more white space.
Any of the fields may be omitted, except that
the digits either before or after the decimal point must be present
and if the
is present then it must be followed by the exponent number.
Tcl_GetBoolean expects src to specify a boolean
value. If src is any of 0, false,
no, or off, then Tcl_GetBoolean stores a zero
value at *boolPtr.
If src is any of 1, true, yes, or on,
then 1 is stored at *boolPtr.
Any of these values may be abbreviated, and upper-case spellings
are also acceptable.