Access variable in attached but removed object

How can I access an object in an attached but deleted environment, when
the object also exists in the .GolbalEnv?

Attaching a variable to the search list generally makes a copy of it, so 
it can't be "attached but deleted".  However, "making a copy" of an 
environment just copies the reference to it, so your environment still 
exists on the search list, it just doesn't have a name in the global 
environment.

I hope the example below makes the question clear:

--8<---------------cut here---------------start------------->8---
tmp <- attach(what=NULL, name="org:variables")
tmp$test = 13
rm(tmp)
test
# > 13
test <- 24
test
# > 24
ls(all=TRUE)
# > character(0)

I don't know why you would have seen character(0) here.  You should have 
seen "test" in the list, because you created it a couple of lines earlier.

#
# how can I access the variable test in the object org:variables in the
# search path?
#
rm(test)
test
# > 13
--8<---------------cut here---------------end--------------->8---

Any suggestions?

You can use assign, or get a reference to the environment using 
as.environment("org:variables"), and access it within that.  For example,

assign("test", 24, pos="org:variables")

or

e <- as.environment("org:variables")
e$test <- 24

Duncan Murdoch