[R] Reflecting R-commands in command line

[M.Kondrin]

Thank you for your replies. I will look into Rcmdr, of course, but not 
in the moment.
I think about making some replacement of R edit() command with GTK toolkit.
I suppose what I would have a script where interface is stored. It is 
either source()-d into R session or loaded as library and called with 
command like gtkedit.start.gui() (so echo will not help because it works 
only for non-interactive sessions). When I would edit some entries in 
data.frame loaded into GUI table, the commands I use to change values of 
data.frame is send into R-session. So if some errors are introduced into 
the frame they can be tracked in R-session transcript and a rollback can 
be done.
Here is an example of what I actually mean. This tkGUI just does an 
assignment Rvar<-Rvalue, with Rvar and Rvalue are taken from entries in 
tk window. The question is how the line evaluated in callback can be 
reflected in command line? Sending the string to stdin() is impossible 
as stdin is opened as read-only.

library(tcltk)
tclVar()->h
tclVar()->z
#set a callback for a button - glue togather string from first and 
second entries  with assignment operator, parse resulting string and 
evaluate it. This string I want to be sent to R-session and somehow eval 
it there.
.Tcl.callback(function(...){eval(parse(text=paste(tclvalue(h),"<-",tclvalue(z))),envir=.GlobalEnv)})->l
# The interface itself - Button and two entries.
.Tcl(paste("toplevel .0 ; grid [button .0.1 -text \"Set var\" -command 
{",l,"}] [entry .0.2 -textvariable ",as.character(h),"] [entry .0.3 
-textvariable ",as.character(z),"]"))