automatically answer a selection in R [duplicate] - r

Question

I am using the R package twitteR to post items to Twitter. I put everything inside of a function and it works fine. However, I would like to run the function without being prompted for a response, and I haven't figured out how to do that. Any suggestions?
Here are the bare bones of my function:
doit <- function(<snip>) {
<snip>
# connect to Twitter
setup_twitter_oauth(api_key, api_secret, access_token, access_token_secret)
<snip>
}
When I run the function from the command line, I am prompted for an interactive response.
[1] "Using direct authentication"
Use a local file to cache OAuth access credentials between R sessions?
1: Yes
2: No
Selection:
I can provide this information directly in a script when the setup_twitter_oauth() function is outside of a function, by entering my response in the following line, much like can be done for other user input functions like readline() or scan().
setup_twitter_oauth(api_key, api_secret, access_token, access_token_secret)
1
However, I haven't been able to get this approach to work when setup_twitter_oauth() is INSIDE of a function.
I would appreciate any suggestions on how to get this to run without requiring user input.
=====
The answer from #NicE below did the trick. I incorporated the options setting in my function as:
doit <- function(<snip>) {
<snip>
# connect to Twitter
origop <- options("httr_oauth_cache")
options(httr_oauth_cache=TRUE)
setup_twitter_oauth(api_key, api_secret, access_token, access_token_secret)
options(httr_oauth_cache=origop)
<snip>
}

Answer 1

You can try setting the httr_oauth_cache option to TRUE:
options(httr_oauth_cache=T)
The twitteR package uses the httr package, on the Token manual page for that package they give tips about caching:
OAuth tokens are cached on disk in a file called .httr-oauth
saved in the current working directory. Caching is enabled if:
The session is interactive, and the user agrees to it, OR
The .httr-oauth file is already present, OR
getOption("httr_oauth_cache") is TRUE
You can suppress caching by setting the httr_oauth_cache option to FALSE.

Answer 2

This works perfectly fine.
install.packages("twitteR", dependencies = T)
install.packages(c('ROAuth','RCurl'))
install.packages("httr")
library(httr)
require('ROAuth')
require('RCurl')
library(twitteR)
reqURL <- "https://api.twitter.com/oauth/request_token"
accessURL <- "https://api.twitter.com/oauth/access_token"
authURL <- "https://api.twitter.com/oauth/authorize"
consumerKey <- "XXXXXXXXXXXXX"
consumerSecret <- "XXXXXXXXXXXXXXXXXXXXX"
twitCred <- OAuthFactory$new(consumerKey=consumerKey,consumerSecret=consumerSecret,requestURL=reqURL,accessURL=accessURL,authURL=authURL)
download.file(url="https://curl.haxx.se/ca/cacert.pem", destfile="cacert.pem")
twitCred$handshake(cainfo="cacert.pem")
setup_twitter_oauth(consumer_key, consumer_secret, access_token, access_secret)

Answer 3

I don't know much about it.
But if it's in batch, maybe try this:
doit <- function(<snip>) {
<snip>
# connect to Twitter
setup_twitter_oauth(api_key, api_secret, access_token, access_token_secret)
< echo 1
<snip>
}
Also have you tried posting the 1 outside the function to see if it does the same?
And maybe it will work if you put the 1 under the snip
These are just suggestions, cause i don't know very much about the topic, but it might help though.