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Tcl_BooleanObj(3)                          Tcl Library Procedures                          Tcl_BooleanObj(3)



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NAME
       Tcl_NewBooleanObj,  Tcl_SetBooleanObj, Tcl_GetBooleanFromObj - manipulate Tcl objects as boolean val-ues values
       ues

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_New-BooleanObj Tcl_NewBooleanObj
       BooleanObj 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_New-BooleanObj Tcl_NewBooleanObj
       BooleanObj  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 representa-tion representation
       tion  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 represen-tation representation
       tation



Tcl                                                  8.0                                   Tcl_BooleanObj(3)