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.

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

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