NAME

       Tcl_NewBooleanObj,  Tcl_SetBooleanObj,  Tcl_GetBooleanFromObj  - manipulate Tcl objects as
       boolean values

SYNOPSIS

       #include <tcl.h>

       Tcl_Obj *
       Tcl_NewBooleanObj(boolValue)

       Tcl_SetBooleanObj(objPtr, boolValue)

       int
       Tcl_GetBooleanFromObj(interp, objPtr, boolPtr)

ARGUMENTS

       int          boolValue (in)      Integer value used to initialize or set a boolean object.
                                        If  the  integer is nonzero, the boolean object is set to
                                        1; otherwise the boolean object is set to 0.

       Tcl_Obj      *objPtr   (in/out)  For Tcl_SetBooleanObj, this points to the  object  to  be
                                        converted  to  boolean  type.  For Tcl_GetBooleanFromObj,
                                        this refers to the object from which  to  get  a  boolean
                                        value;  if  objPtr  does  not  already point to a boolean
                                        object, an attempt will be made to convert it to one.

       Tcl_Interp   *interp   (in/out)  If an error occurs during conversion, an error message is
                                        left  in the interpreter's result object unless interp is
                                        NULL.

       int          *boolPtr  (out)     Points to place where  Tcl_GetBooleanFromObj  stores  the
                                        boolean value (0 or 1) obtained from objPtr.
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DESCRIPTION

       These  procedures  are  used  to create, modify, and read boolean Tcl objects from C code.
       Tcl_NewBooleanObj and Tcl_SetBooleanObj will create a new object of boolean type or modify
       an  existing object to have boolean type.  Both of these procedures set the object to have
       the boolean value (0 or 1) specified by boolValue; if boolValue is nonzero, the object  is
       set  to  1, otherwise to 0.  Tcl_NewBooleanObj returns a pointer to a newly created object
       with reference count zero.  Both procedures set the object's type to be boolean and assign
       the   boolean   value   to   the   object's   internal  representation  longValue  member.
       Tcl_SetBooleanObj invalidates any old string representation and,  if  the  object  is  not
       already a boolean object, frees any old internal representation.

       Tcl_GetBooleanFromObj  attempts  to return a boolean value from the Tcl object objPtr.  If
       the object is not already a boolean object, it will attempt to convert it to one.   If  an
       error  occurs  during  conversion, it returns TCL_ERROR and leaves an error message in the
       interpreter's result object  unless  interp  is  NULL.   Otherwise,  Tcl_GetBooleanFromObj
       returns  TCL_OK  and  stores  the  boolean  value in the address given by boolPtr.  If the
       object is not already a  boolean  object,  the  conversion  will  free  any  old  internal
       representation.   Objects  having a string representation equal to any of 0, false, no, or
       off have a boolean value 0; if the string representation is any of 1, true, yes, or on the
       boolean  value  is  1.   Any  of  these  string  values may be abbreviated, and upper-case
       spellings are also acceptable.

SEE ALSO

       Tcl_NewObj, Tcl_DecrRefCount, Tcl_IncrRefCount, Tcl_GetObjResult

KEYWORDS

       boolean, boolean object, boolean  type,  internal  representation,  object,  object  type,
       string representation