R code to turn windows computer off after completion of program [duplicate] - r

I want R to shutdown my computer after my (extensive) simulation and saving results, is this possible?

Yes, look at the function shutdown in the package fun.
The flags for system command shutdown depends on your operating system, the function simply calls the appropriately flagged command.
fun::shutdown
function (wait = 0)
{
Sys.sleep(wait)
ifelse(.Platform$OS.type == "windows", shell("shutdown -s -t 0"),
system("shutdown -h now"))
}

R can send commands to the system with ?system, and so whatever is required for Windows can be done with that:
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/shutdown.mspx?mfr=true
R has a .Last() function controlled by quit() (or q()) with its runLast argument, so this is where you would send the shutdown commands via system, so that it occurs after quitting R. Saving objects with R is done with save or save.image, though there is a default to save as well with quit().

Executing
system("shutdown -s")
will shut your computer down. Just add it at the end of your script

Related

How to release R's prompt when using 'system'?

I am writing an R code on a Linux system using RStudio. At some point in the code, I need to use a system call to a command that will download a few thousand of files from the lines of a text file:
down.command <- paste0("parallel --gnu -a links.txt wget")
system(down.command)
However, this command takes a little while to run (a couple of hours), and the R prompt stays locked while the command runs. I would like to keep using R while the command runs on the background.
I tried to use nohup like this:
down.command <- paste0("nohup parallel --gnu -a links.txt wget > ~/down.log 2>&1")
system(down.command)
but the R prompt still gets "locked" waiting for the end of the command.
Is there any way to circumvent this? Is there a way to submit system commands from R and keep them running on the background?
Using ‘processx’, here’s how to create a new process that redirects both stdout and stderr to the same file:
args = c('--gnu', '-a', 'links.txt', 'wget')
p = processx::process$new('parallel', args, stdout = '~/down.log', stderr = '2>&1')
This launches the process and resumes the execution of the R script. You can then interact with the running process via the p name. Notably you can signal to it, you can query its status (e.g. is_alive()), and you can synchronously wait for its completion (optionally with a timeout after which to kill it):
p$wait()
result = p$get_exit_status()
Based on the comment by #KonradRudolph, I became aware of the processx R package that very smartly deals with system process submissions from within R.
All I had to do was:
library(processx)
down.command <- c("parallel","--gnu", "-a", "links.txt", "wget", ">", "~/down.log", "2>&1")
processx::process$new("nohup", down.comm, cleanup=FALSE)
As simple as that, and very effective.

Starting Rserve in debug mode and printing variables from Tableau to R

I can't start Rserve in debug mode.
I wrote these commands in R:
library(Rserve)
Rserve(debug=T, args="RS-enable-control", quote=T, port = 6311)
library(RSclient)
c=RSconnect(host = "localhost", port = 6311)
RSeval(c, "xx<-12")
RSeval(c, "2+6")
RSeval(c, "xx")
RSclose(c)
install.packages("fpc")
I placed the Rserve_d.exe in the same directory where the R.dll file is located. But when I launch it and I launch Tableau with the Rserve connection I can't see anything in the debug console, just these few lines.
Rserve 1.7-3 () (C)Copyright 2002-2013 Simon Urbanek
$Id$
Loading config file Rserv.cfg
Failed to find config file Rserv.cfg
Rserve: Ok, ready to answer queries.
-create_server(port = 6311, socket = <NULL>, mode = 0, flags = 0x4000)
INFO: adding server 000000000030AEE0 (total 1 servers)
I tried another solution by the command Rserve(TRUE) in R, but I can't see the transactions between R and Tableau neither in the Rstudio console.
I wanted then to print the output of the variable in R from the R-script function, by print(.arg1). But nothing appears in the R console
but when I run print in the R console it works fine.
According to this article*, RServe should be run with the following command to enable debugging:
R CMD Rserve_d
An alternative is to use the ‘write.csv’ command within the calculated field that calls an R script, as suggested by this FAQ document from Tableau
Starting Rserve_d.exe from command line works. Most likely you have multiple instances of Rserve running and Tableau is sending requests to one that is not Rserve_d running in the command line.
Did you try killing all Rserve processes and then starting Rserve_d from command line?
If you don't want to run from the command line you can try starting Rserve in process from RStudio by typing run.Rserve() then using print() statements in your Tableau calculated fields for things you want to print.
In the R bin directory, you have two executables Rserve for normal execution and Rserve.dbg for debug execution. Use
R CMD Rserve.dbg
My OS is CENTOS7 and I am using the R installation from anaconda. If your RServe debug executable has a different name you should be using that.

Calling external program from R with multiple commands in system

I am new to programming and mainly I am able to do some scripts within R, but for my work I need to call an external program. For this program to work on the ubuntu's terminal I have to first use setenv and then execute the program. Googling I've found the system () and Sys.setenv() functions, but unfortunately I can make it function.
This is the code that does work in the ubuntu terminal:
$ export PATH=/home/meme/bin:$PATH
$ mast "/home/meme/meme.txt" "/home/meme/seqs.txt" -o "/home/meme/output" -comp
Where the first two arguments are input files, the -o argument is the output directory and the -comp is another parameter for the program to run.
The reason that I need to do it in R despite it already works in the terminal is because I need to run the program 1000 times with 1000 different files so I want to make a for loop where the input name changes in every loop and then analyze every output in R.
I have already tried to use:
Sys.setenv(PATH="/home/meme/bin"); system(mast "/home/meme/meme.txt" "/home/meme/seqs.txt" -o "/home/meme/output" -comp )
and
system(Sys.setenv(PATH="/home/meme/bin") && mast "/home/meme/meme.txt" "/home/meme/seqs.txt" -o "/home/meme/output" -comp )
but always received:
Error: unexpected constant string in "system(mast "/home/meme/meme.txt""
or
Error: unexpected symbol in "system(Sys.setenv(PATH="/home/meme/bin") && mast "/home/meme/meme.txt""
At this point I have run out of ideas to make this work. If this has already been answered, then my googling have just been poor and I would appreciate any links to its response.
Thank you very much for your time.
Carlos
Additional details:
I use Ubuntu 12.04 64-bits version, RStudio version 0.97.551, R version 3.0.2 (2013-09-25) -- "Frisbee Sailing" Platform: x86_64-pc-linux-gnu (64-bit).
The program I use (MAST) finds a sequence pattern in a list of letters and is part of the MEME SUIT version 4.9.1 found in http://meme.nbcr.net/meme/doc/meme-install.html and run through command line. The command-line usage for mast is:
mast <motif file> <sequence file> [options]
Construct the string you want to execute with paste and feed that to system:
for(i in 1:10){
cmd=paste("export FOO=",i," ; echo \"$FOO\" ",sep='')
system(cmd)
}
Note the use of sep='' to stop paste putting spaces in, and back-quoting quote marks in the string to preserve them.
Test before running by using print(cmd) instead of system(cmd) to make sure you are getting the right command built. Maybe do:
if(TESTING){print(cmd)}else{system(cmd)}
and set TESTING=TRUE or FALSE in R before running.
If you are going to be running more than one shell command per system call, it might be better to put them all in one shell script file and call that instead, passing parameters from R. Something like:
cmd = paste("/home/me/bin/dojob.sh ",i,i+1)
system(cmd)
and then dojob.sh is a shell script that parses the args. You'll need to learn a bit more shell scripting.

R function to connect to wireless

I am running a code for a client. Is there a R function / command to connect the computer to the available wireless and type in the passcode automatically?
Probably not.
However, you can run any OS command with system, so if you have a shell command foo which does what you want, you can just do system("foo") in R.
Most connections to the "outside world" with R are handled through the OS version of system-level 'libcurl' package. There is a package for R called RCurl. The authentication system is described in the variaous pages of:
help(package="RCurl") # brings up the index page.
help(getURL, package="RCurl") # has examples of authentication to a server with R code.
You should also read:
?connections

Shutdown Windows after simulation

I want R to shutdown my computer after my (extensive) simulation and saving results, is this possible?
Yes, look at the function shutdown in the package fun.
The flags for system command shutdown depends on your operating system, the function simply calls the appropriately flagged command.
fun::shutdown
function (wait = 0)
{
Sys.sleep(wait)
ifelse(.Platform$OS.type == "windows", shell("shutdown -s -t 0"),
system("shutdown -h now"))
}
R can send commands to the system with ?system, and so whatever is required for Windows can be done with that:
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/shutdown.mspx?mfr=true
R has a .Last() function controlled by quit() (or q()) with its runLast argument, so this is where you would send the shutdown commands via system, so that it occurs after quitting R. Saving objects with R is done with save or save.image, though there is a default to save as well with quit().
Executing
system("shutdown -s")
will shut your computer down. Just add it at the end of your script

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