Question

I am bit new to R and have a question about a program I am trying to write. I am hoping to take in files (as many as a user pleases) with a while loop (eventually using read.table on each) but it keeps breaking on me.
Here is what I have so far:

cat("Please enter the full path for your files, if you have no more files to add enter 'X': ")
fil<-readLines(con="stdin", 1)
cat(fil, "\n")
while (!input=='X' | !input=='x'){
inputfile=input
input<- readline("Please enter the full path for your files, if you have no more files to add enter 'X': ")
}
if(input=='X' | input=='x'){
exit -1
}

When I run it (from the commandline (UNIX)) I get these results:

> library("lattice")
> 
> cat("Please enter the full path for your files, if you have no more files to add enter 'X': ")
Please enter the full path for your files, if you have no more files to add enter 'X': > fil<-readLines(con="stdin", 1)
x
> cat(fil, "\n")
x 
> while (!input=='X' | !input=='x'){ 
+ inputfile=input
+ input<- readline("Please enter the full path for your files, if you have no more files to add enter 'X': ")
+ }
Error: object 'input' not found
Execution halted

I am not quite sure how to fix the problem, but I am pretty sure that it is probably a simple problem.
Any suggestions?
Thanks!

Answer 1

when you first run the script input doesnt exist. Assign

input<-c() 

say before your while statement or put
inputfile=input
below input<- readline....