[R] Problems with scan

[David C. Howell]

I have been having problems with using scan(). I searched the archives 
and found someone with the same problem several years ago, but did not 
find a solution.

I want to prompt the user for input, scan in that input, and then go on 
to use it as a variable.

The simplest version of my program is

cat("enter m","\n")
m <- scan(n = 1, quiet = T)
m

If I enter these lines one at a time, they work perfectly and I get the 
following output, which is just want I want..
 > cat("enter m","\n")
enter m
 > m <- scan(n = 1, quiet = T)
1: 24
 > m
[1] 24
 >

However if I submit the three lines together, as you would when running 
a program, I get

 > cat("enter m","\n")
enter m
 > m <- scan(n = 1, quiet = T)
1: m
1:
Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, 
na.strings,  :
  scan() expected 'a real', got 'm'
 >

In this case the program is reading the line after the scan function as 
the input to scan, rather than pausing for my entry. The help archives 
suggested putting this as a function "e.g., getn()" but that gives the 
same result.

The scan help file doesn't address this and the help archives don't give 
me what I need. How do I cause the program to wait for keyboard entry 
from me?

I am running version 2.8 on a Windows machine, but the problem goes back 
to much earlier versions.

While I'm asking, is there a way to suppress the echoing of lines? I 
would like to omit the lines above that begin with ">". I cannot find 
"echo" using help.search and can't think of another name to search under.

Thanks,

Dave Howell

-- 
David C. Howell
PO Box 770059
627 Meadowbrook Circle
Steamboat Springs, CO
80477