How do I include a variable file name in a system() function to call Windows commands

Question

This is likely a stupid question but I have not found a work around (at least in anything I have searched for, though I might just not be using the right search parameters.)

I want to call an executable in Windows, and send a file to it (in this case a Blaise man file), the name of which is variable in my script.

So, for example, I have

x<-2
myfile<-c(paste("FileNumber",x,".man", sep="")
system("myapp.exe" myfile)

But I simply get

Error: unexpected symbol in "system("myapp.exe" myfile"

as if the command is not recognizing the object as myfile, instead taking "myfile" as literal text.

I tried using a paste function to create a whole line command, but that also did not work.

Answer 1

The system command will not concatenate the string and the myfile object together, you have to do it yourself.

So, try this instead:

x<-2
myfile<-c(paste("FileNumber",x,".man", sep=""))
cmd <- paste("myapp.exe", myfile)
system(cmd)

Or just:

x<-2
system(paste("myapp.exe", c(paste("FileNumber",x,".man", sep=""))))