Jannis
2013-Mar-14 16:13 UTC
[R] does R read commands from scripts instantanously or seuqently during processing
Dear R community, when I source a script into R via: R --slave < scriptname.R is the whole script file read at once during startup or is each indivdual line of code read seqnetially during the execution (i.e. directly before r processes the respective command)? In other words, can I savely edit the scriptname.R file even when an active R process still runs the command above? Thanks for your help Jannis
Jeff Newmiller
2013-Mar-14 16:52 UTC
[R] does R read commands from scripts instantanously or seuqently during processing
Your use of the "<" redirection operator is an operating system feature, not an R feature. I am not aware of any operating system that that would function properly in the use case you describe. It is possible, and common, to construct your input file as a stream as you go. But a stream is not a file on disk. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnewmil at dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity. Jannis <bt_jannis at yahoo.de> wrote:>Dear R community, > > >when I source a script into R via: > > >R --slave < scriptname.R > > >is the whole script file read at once during startup or is each >indivdual line of code read seqnetially during the execution (i.e. >directly before r processes the respective command)? In other words, >can >I savely edit the scriptname.R file even when an active R process >still >runs the command above? > > >Thanks for your help >Jannis > >______________________________________________ >R-help at r-project.org mailing list >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.
Rolf Turner
2013-Mar-14 21:47 UTC
[R] does R read commands from scripts instantanously or seuqently during processing
On 03/15/2013 05:13 AM, Jannis wrote:> Dear R community, > > > when I source a script into R via: > > > R --slave < scriptname.R > > > is the whole script file read at once during startup or is each > indivdual line of code read seqnetially during the execution (i.e. > directly before r processes the respective command)? In other words, > can I savely edit the scriptname.R file even when an active R process > still runs the command above?Experiment. Build a toy script with a loop that never terminates. Set it going. Edit the script and change the code so that the loop terminates. See what happens. [It seems to me that nothing happens, so that you *can* "safely" edit the script while the process runs. But further experimentation would be advisable.] cheers, Rolf Turner