September 3, 2014

bash script, erase previous line?

Q: In lots of Linux programs, like curl, wget, and anything with a progress meter, they have the bottom line constantly update, every certain amount of time. How do I do that in a bash script?


A:

{
for pc in $(seq 1 100); do
echo -ne "$pc%\033[0K\r"
usleep 100000
done
echo
}

The "\033[0K" will delete to the end of the line - in case your progress line gets shorter at some point, although this may not be necessary for your purposes.

The "\r" will move the cursor to the beginning of the current line

The -n on echo will prevent the cursor advancing to the next line
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