[R] iterative loop with user input?

[Christopher Marcum]

Hello R-Users,

I would like to use an iterative loop to collect user input from within a
function. I'm sure that this would be some combination of "for","break",
and "next" but have not been able to get the syntax down.

I would like to print some text to the screen at each step in the loop,
ask the user for input which is saved in an object, and then advance the
loop.

Here is an example:

#anchor is a file with unique ids
anchor<-rep(1:30)
anchor<-paste(anchor,"uid",sep="")

#codelist is where I would like to store user input
codelist<-NULL

for(i in 1:30) {
#tell the user which ID is being coded
print(paste("You are coding unique ID",anchor[i],sep=":   "))
#Read a line from a text file:
print(readLines(file="file_with_30_lines.txt",warn=F)[i])
#Ask the user for input
codelist[i]<-readline(paste("Select one of the following: \n \t please
enter 1, 2, or 3: \n Enter Your Response HERE:   ",sep=""))
}

Ideally, loop should work from inside a function.

Any tips? Thanks in advance for your time and patience.

Best,
Chris Marcum
Sociology/Cal(it)^2
University of California-Irvine