oracular (3) Tcl_GetBoolean.3tcl.gz

NAME

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

SYNOPSIS

       #include <tcl.h>

       int
       Tcl_GetInt(interp, src, intPtr)

       int
       Tcl_GetDouble(interp, src, doublePtr)

       int
       Tcl_GetBoolean(interp, src, intPtr)

ARGUMENTS

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

       const char *src (in)                Textual value to be converted.

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

       double *doublePtr (out)             Points  to  place  to  store  double-precision  floating-point  value
                                           converted from src.
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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 src 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 src does not
       have the proper syntax for the desired type then TCL_ERROR is returned, an error message is left  in  the
       interpreter's result, and nothing is stored at *intPtr or *doublePtr.

       Tcl_GetInt  expects  src  to  consist of a collection of integer digits, optionally signed and optionally
       preceded and followed by white space.  If the first two characters of src after the optional white  space
       and  sign  are  “0x”  then  src  is  expected  to  be  in hexadecimal form;  otherwise, if the first such
       characters are “0o” then src is expected to be in octal form;  otherwise, if the  first  such  characters
       are  “0b”  then src is expected to be in binary form;  otherwise, if the first such character is “0” then
       src 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 “e”; 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 “e” is present then it must be followed by the
       exponent number. If there are no fields apart from the sign and initial  sequence  of  digits  (i.e.,  no
       decimal  point  or exponent indicator), that initial sequence of digits should take one of the forms that
       Tcl_GetInt supports, described above. The use of “,” as a decimal point is not supported nor  should  any
       other sort of inter-digit separator be present.

       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 *intPtr.  If src is any of 1, true, yes, or on, then 1 is stored at
       *intPtr.  Any of these values may be abbreviated, and upper-case spellings are also acceptable.

KEYWORDS

       boolean, conversion, double, floating-point, integer