Re: [Tclplugin-core] TCl problem

[Donald G P. <dg...@em...>]

> During the Initialization we request TCL to allocate a pointer "p_tcl_c_str" (say 1024 bytes) using the 
Tcl_Alloc call. When we later write to this variable from a TCL Script, TCL reallocates this variable 
memory which is equal to length of the string that is being written. For Example if we do a "set 
p_tcl_c_str Hello_World", It will reallocate this variable only 12 bytes and release the previous chunk. 
As, in the C code we are not aware of this change we write to the C variable expecting that it would be 
able to support the write upto 1024 bytes and hence the process crashes.

It sounds like you are attempting to program based on a mistaken
assumption that a C variable of a particular name is somehow tied
to a Tcl variable (a Tcl_Var) of that same name.  No such
automatic connection exists.

If you need access to the same variable at both Tcl and C levels,
you should be working with Tcl_Var's all the time and use the
procedures like Tcl_SetVar() and Tcl_GetVar() to read and write them.

Another option that might be suitable for certain situations is
to create a "link" between a C variable and a Tcl variable using
the Tcl_LinkVar() family of routines.

If these pointers do not answer your problem, then try again with
some specific code examples of what you are attempting to do.

| Don Porter          Mathematical and Computational Sciences Division |
| don...@ni...             Information Technology Laboratory |
| http://math.nist.gov/~DPorter/                                  NIST |
|______________________________________________________________________|