SYNOPSIS
#include <tcl.h>
int Tcl_LinkVar(interp, varName, addr, type)
Tcl_UnlinkVar(interp, varName)
Tcl_UpdateLinkedVar(interp, varName)
ARGUMENTS
- Tcl_Interp *interp (in)
-
Interpreter that contains varName. Also used by
Tcl_LinkVar() to return error messages. - char *varName (in)
-
Name of global variable. Must be in writable memory: Tcl may make temporary modifications to it while parsing the variable name.
- char *addr (in)
-
Address of C variable that is to be linked to varName.
- int type (in)
-
Type of C variable. Must be one of TCL_LINK_INT, TCL_LINK_DOUBLE, TCL_LINK_BOOLEAN, or TCL_LINK_STRING, optionally OR'ed with TCL_LINK_READ_ONLY to make Tcl variable read-only.
DESCRIPTION
The type argument specifies the type of the C variable, and must have one of the following values, optionally OR'ed with TCL_LINK_READ_ONLY:
- TCL_LINK_INT
-
The C variable is of type int. Any value written into the Tcl variable must have a proper integer form acceptable to
Tcl_GetInt() ; attempts to write non-integer values into varName will be rejected with Tcl errors. - TCL_LINK_DOUBLE
-
The C variable is of type double. Any value written into the Tcl variable must have a proper real form acceptable to
Tcl_GetDouble() ; attempts to write non-real values into varName will be rejected with Tcl errors. - TCL_LINK_BOOLEAN
-
The C variable is of type int. If its value is zero then it will read from Tcl as 0; otherwise it will read from Tcl as 1. Whenever varName is modified, the C variable will be set to a 0 or 1 value. Any value written into the Tcl variable must have a proper boolean form acceptable to
Tcl_GetBoolean() ; attempts to write non-boolean values into varName will be rejected with Tcl errors. - TCL_LINK_STRING
-
The C variable is of type char *. If its value is not null then it must be a pointer to a string allocated with
Tcl_Alloc() . Whenever the Tcl variable is modified the current C string will be freed and new memory will be allocated to hold a copy of the variable's new value. If the C variable contains a null pointer then the Tcl variable will read as NULL.
If the TCL_LINK_READ_ONLY flag is present in type then the variable will be read-only from Tcl, so that its value can only be changed by modifying the C variable. Attempts to write the variable from Tcl will be rejected with errors.
PORTABILITY
Windows 8.1. Windows Server 2012 R2. Windows 10. Windows Server 2016. Windows Server 2019. Windows 11. Windows Server 2022.
AVAILABILITY
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition
PTC MKS Toolkit 10.4 Documentation Build 39.