while READ loop problem

caps_phisto · 02-05-2007, 09:16 AM

I have setup a script that reads input from a text file using the following type of loop:

Code:

while read LINE; do...done

However, I wish to prompt the user for input within that loop doing something similar to this:

Code:

 while read LINE; do
echo "Enter your name:  "
read MYNAME 
done

But when I run the script it won't pause on the input prompt. Instead it simply just bypasses it and stores nothing in the variable. Is there something I am missing?

Thanks in advance.

colucix · 02-05-2007, 09:50 AM

The problem here is that you are trying to read both the text file and the user input from standard input. You have to separate them in some way. One idea is to assign a file descriptor to the text file and leave the standard input for user input, e.g.

Code:

#!/bin/bash
exec 3<>$1
while read -u 3 LINE; do
echo -n "Enter your name:  "
read MYNAME
done

In this example the file descriptor 3 is assigned to the text file passed as argument to the script itself, while the user input comes from file descriptor 0 (standard input). You have to execute the script as in:

Code:

./name_of_the_script name_of_text_file

without the < redirection

caps_phisto · 02-05-2007, 09:57 AM

Excellent! That worked like a charm! THANKS!

colucix · 02-05-2007, 09:58 AM

You're welcome!