How do you get user input when running a bash script from a url?

Question

Consider this bash script :

#!/bin/bash
while true; do
    read -p "Give me an answer ? y/n : " yn
    case $yn in
        [Yy]* ) answer=true ; break;;
        [Nn]* ) answer=false ; break;;
        * ) echo "Please answer yes or no.";;
    esac
  done

if $answer 
  then 
    echo "Doing something as you answered yes"
      else 
    echo "Not doing anything as you answered no" 
fi

When run from the command line using :

$ ./script-name.sh

It works just as expected with the script waiting for you to answer y or n.

However when I upload to a url and attempt to run it using :

$ curl http://path.to/script-name.sh | bash

I get stuck in a permanent loop with the script saying Please answer yes or no. Apparently the script is receiving some sort of input other than y or n.

Why is this? And more importantly how can I achieve user input from a bash script called from a url?

You've redirected standard input for the shell already. That's where your script has just come from. So when bash tries to read more information from standard input it just gets EOF and spins. — Etan Reisner
– Etan Reisner, Commented Nov 11, 2014 at 19:26
well cat script-name.sh | bash would not work better than your curl command either... — philippe lhardy
– philippe lhardy, Commented Nov 11, 2014 at 20:32

Scrutinizer · Accepted Answer · 2013-03-03 11:12:19Z

8

Perhaps use an explicit local redirect:

read answer < /dev/tty

answered Mar 3, 2013 at 11:12

Scrutinizer

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2 Comments

David Sulpy Over a year ago

The problem I'm having with this answer is that the read happens before the echos explaining what to type happen...

Bjoern Dahlgren Over a year ago

@DavidSulpy try this: read -p "Enter answer:" answer < /dev/tty

anubhava · Accepted Answer · 2014-11-11 19:31:01Z

6

You can run it like this:

bash -c "$(curl -s http://path.to/script-name.sh)"

Since you're supplying content of bash script to bash interpreter. Use curl -s for silent execution.

answered Nov 11, 2014 at 19:31

anubhava

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