int *major (out) Major version number of the Tcl library.
int *minor (out) Minor version number of the Tcl library.
int *patchLevel (out) The patch level of the Tcl library (or alpha or beta number).
Tcl_ReleaseType *type (out) The type of release, also indicates the type of patch level. Can be one of TCL_ALPHA_RELEASE,
TCL_BETA_RELEASE, or TCL_FINAL_RELEASE.
Tcl_GetVersion should be used to query the version number of the Tcl library at runtime. This is useful when using a dynamically loaded
Tcl library or when writing a stubs-aware extension. For instance, if you write an extension that is linked against the Tcl stubs library,
it could be loaded into a program linked to an older version of Tcl than you expected. Use Tcl_GetVersion to verify that fact, and possi-
bly to change the behavior of your extension.
Tcl_GetVersion accepts NULL for any of the arguments. For instance if you do not care about the patchLevel of the library, pass a NULL for
the patchLevel argument.