ls() pattern question

Hello,


First, `ls` does not support `!=` for pattern, but it's actually throwing a
different error. For `rm`, the objects provided into `...` are substituted
(not evaluated), so you should really do something like

rm(list = ls(pattern = ...))

As for all except "con", "DB2", and "ora", I would try something like

setdiff(ls(), c("con", "DB2", "ora"))

and then add `rm` to that like

rm(list = setdiff(ls(), c("con", "DB2", "ora")))

On Wed, Jul 14, 2021 at 7:41 PM Kai Yang via R-help <r-help at r-project.org>
wrote:

Hello List,
I have many data frames in environment.  I need to keep 3 data frames
only, con DB2 and ora.
I write the script to do this.
rm(ls(pattern != c("(con|DB2|ora)")))


but it give me an error message:


Error in rm(ls(pattern != c("(con|DB2|ora)"))) :
  ... must contain names or character strings

I think the pattern option doesn't support != ? and is it possible to fix
this?
Thank you,
Kai



        [[alternative HTML version deleted]]

______________________________________________
R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.