Tcl_NewBooleanObj(), Tcl_SetBooleanObj(), Tcl_GetBooleanFromObj()

manipulate Tcl objects as boolean values 

Tcl Library Procedures

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.

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.

PORTABILITY

Windows 10. Windows Server 2016. Windows Server 2019. Windows 11. Windows Server 2022. Windows Server 2025.

AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

SEE ALSO

Functions:
Tcl_DecrRefCount(), Tcl_GetObjResult(), Tcl_IncrRefCount(), Tcl_NewObj()

PTC MKS Toolkit 10.5 Documentation Build 40.