getint(3Tcl)

NAME
     Tcl_GetInt, Tcl_GetDouble, Tcl_GetBoolean - convert from string to
     integer, double, or boolean

SYNOPSIS
     #include <tcl.h>

     int
     Tcl_GetInt(interp, string, intPtr)

     int
     Tcl_GetDouble(interp, string, doublePtr)

     int
     Tcl_GetBoolean(interp, string, boolPtr)

ARGUMENTS
     Tcl_Interp   *interp      (in)      Interpreter to use for error
                                         reporting.

     char         *string      (in)      Textual value to be converted.

     int          *intPtr      (out)     Points to place to store integer
                                         value converted from string.

     double       *doublePtr   (out)     Points to place to store double-
                                         precision floating-point value
                                         converted from string.

     int          *boolPtr     (out)     Points to place to store boolean
                                         value (0 or 1) converted from string.


DESCRIPTION
     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 string argument, converts it
     to an internal form of a particular type, and stores the converted value
     at the location indicated by the procedure's third argument.  If all goes
     well, each of the procedures returns TCL_OK.  If string doesn't have the
     proper syntax for the desired type then TCL_ERROR is returned, an error
     message is left in interp->result, and nothing is stored at *intPtr or
     *doublePtr or *boolPtr.

     Tcl_GetInt expects string to consist of a collection of integer digits,
     optionally signed and optionally preceded by white space.  If the first
     two characters of string are ``0x'' then string is expected to be in
     hexadecimal form;  otherwise, if the first character of string is ``0''
     then string is expected to be in octal form;  otherwise, string is
     expected to be in decimal form.
     Tcl_GetDouble expects string 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 ``e'';  and a signed decimal exponent.
     Any of the fields may be omitted, except that the digits either before or
     after the decimal point must be present and if the ``e'' is present then
     it must be followed by the exponent number.

     Tcl_GetBoolean expects string to specify a boolean value.  If string is
     any of 0, false, no, or off, then Tcl_GetBoolean stores a zero value at
     *boolPtr.  If string 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.


KEYWORDS
     boolean, conversion, double, floating-point, integer