I done something very similar -- have R watch a file, and whenever new data is added to the file, read the new data from the file. In my case, new data was arriving once per minute, so I needed to have R wait about a minute before looking for new data.
On my unix-based system, I found that if I usd Sys.sleep( N ) then cpu usage immediately went up drastically. If the the system is otherwise fairly idle, cpu usage goes up to nearly 100%. A cpu monitor shows that R is using the cpu cycles. If I use instead system('sleep N') cpu usage does not go up. (where N is the number of seconds to sleep) > version _ platform powerpc-apple-darwin7.9.0 arch powerpc os darwin7.9.0 system powerpc, darwin7.9.0 status major 2 minor 1.1 year 2005 month 06 day 20 language R At 12:13 PM -0700 7/29/05, Tae-Hoon Chung wrote: >Hi, All; > >I have a question. In R, what is the best way to make R idle for a while and >try something again later? For example, suppose there is an R job which >accesses a file that may be shared with other active jobs. So when the file >is being accessed by other job, your job will not be able to access the file >and your job will crash because of that. To avoid this, you want your job to >try to access the file repeatedly with some time interval, say every 10 >seconds or something like that. Which is the best way to do this in R? > >Thanks in advance, > >Tae-Hoon Chung > >Post-Doctoral Researcher >Translational Genomics Research Institute (TGen) >445 N. 5th Street (Suite 530) >Phoenix, AZ 85004 >1-602-343-8724 (Direct) >1-480-323-9820 (Mobile) >1-602-343-8840 (Fax) > >______________________________________________ >R-help@stat.math.ethz.ch mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html -- -------------------------------------- Don MacQueen Environmental Protection Department Lawrence Livermore National Laboratory Livermore, CA, USA ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html