Bash-style progress bar (/w elapsed time) to show while long-running sub-processes being called.

progress.sh

#!/bin/bash
# Bash-style progress bar (/w elapsed time) to show while long-running sub-processes being called.
# Copyright: 2015, Stephan Schmitz <[email protected]>
# License: MIT

# 1. Paste the `progress` function in your bash script.
function progress () {
    s=0.5;
    f=0.25;
    echo -ne "\r\n";
    while true; do
           sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[             ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[>            ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[-->          ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[--->         ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[---->        ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[----->       ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[------>      ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[------->     ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[-------->    ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[--------->   ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[---------->  ] Elapsed: ${s} secs." \
        && sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[-----------> ] Elapsed: ${s} secs.";
           sleep $f && s=`echo ${s} + ${f} + ${f} | bc` && echo -ne "\r\t[------------>] Elapsed: ${s} secs.";
    done;
}

# 2. Then, somewhere in your script, wrap any long running process call as follows:
while true; do progress; done &
    sleep 20; # or, whatever
kill $!; trap 'kill $!' SIGTERM