search for: tclrawvalue

...confirm that the tcl representation does indeed have the NULLs: > .Tcl("binary scan $tcls H* tmps") <Tcl> 1 > tclvalue("tmps") [1] "48657265206172652031004865726520697320320000416e642066696e616c6c79207468726565000000" I would naively suggest something like tclrawvalue() and/or as.raw() utilizing Tcl_GetByteArrayFromObj A good discussion of the basics of this issue for general tcl embedding can be found here: http://www2.tcl.tk/1180 For those who might be wondering "what the heck are you doing trying to pass binary data from tcl?", the answer is that...