Question

I’ve got a bash script that’s reading essentially the output of telnet (actually socat to a unix domain socket).

while read -r LINE; do
    if [ "$USER_DATA_FLAG" == "true" ]; then   #Evaluates to false for the moment
        ...
    else
        printf "%s\n" "Variable> $LINE" >>$DEBUG_LOG
        printf "%s\n" "Line  xxxxz $LINE yxxxxx" >>$DEBUG_LOG
        ...
    fi
done

This yields the following incomprehensible output:

Variable> >INFO:OpenVPN Management Interface Version 1 -- type 'help' for more info
yxxxxxxxxz >INFO:OpenVPN Management Interface Version 1 -- type 'help' for more info
Variable> OpenVPN CLIENT LIST
yxxxxxxxxz OpenVPN CLIENT LIST

The first printf statement works fine and shows exactly what I expect based on my experience at the terminal. But the second printf statement goes nuts, reverses the order of some the characters and prints $LINE entirely in the wrong place!

Answer 1

$LINE has a \r in it, which is sending the cursor back to column 1. Use parameter substitution or tr to remove it.

$ foo=$'1\r23'
$ echo "$foo"
23
$ echo "${foo/$'\r'/}"
123