Hi all,
I am attempting to port a bash script that worked fine on RedHat 7.1 to Fedora Core 1. I am having trouble reading a file into a variable. Nothing gets read into the variable. The source file has not changed.

Sample source file:
4.40.0.0/19
12.211.156.0/22
12.221.220.0/22

It goes on for 454 lines or so.

I copied the troublesome section into a test script

#! /bin/bash
BlockedHosts="/etc/rc.d/blocked.lst"
if [ -f "$BlockedHosts" ]; then
while read ATTACKERS; do
echo "$ATTACKERS" > /dev/null
done < "$BlockedHosts";
fi
echo "$ATTACKERS"

When I run my test script, the result is a blank line.

I also tried this mod with no success based on another post in this forum.

#! /bin/bash
BlockedHosts="/etc/rc.d/blocked.lst"
if [ -f "$BlockedHosts" ]; then
cat ${BlockedHosts} | while read ATTACKERS; do
echo "$ATTACKERS" > /dev/null
done < "$BlockedHosts";
fi
echo "$ATTACKERS"

I did not come up with the first version of the code, I merely copied it from the previous script that worked on the RH7.1 that my coworker created. He can't figure it out either. He said this problem started on RedHat 8.
I am not quite a newbie, but close enough...
Thanks for any assistance

> When I run my test script, the result is a blank line.

The result probably is the LAST line of your file.
If the last line is empty, you get an empty line.

All the other lines are sent to /dev/null (the binary black hole)

what is this script supposed to do ?

Thanks for attempting to answer.
The last line was a blank in blocked.lst, so I removed that and I received the same result an empty line. By your implied answer I should have seen instead:
221.144.0.0/12
But I did not. So it's not reading the file period as far as I can tell.

So if the /dev/null in this statement is incorrect,
echo "$ATTACKERS" > /dev/null
what is correct? What do I echo it into?

Thanks

Here's what worked... I found it myself...

ATTACKERS=$(cat $BlockedHosts)

I had to find the advanced bash shell guide for this, command substitution is what it is called.

Also if I use:
echo $ATTACKERS
everything is run onto one line.
If I use:
echo "$ATTACKERS"
then my newlines are preserved....

Go figure....

>#! /bin/bash
>BlockedHosts="/etc/rc.d/blocked.lst"
>if [ -f "$BlockedHosts" ]; then
>cat ${BlockedHosts} | while read ATTACKERS; do
>echo "$ATTACKERS" > /dev/null
>done < "$BlockedHosts";
>fi
>echo "$ATTACKERS"

The last line is always empty.
reason: the while loop ends when there
are no more data left (i.e. empty)

still don't understand what the script is supposed to do