Converting tab to space

Problem

You want to convert tab to space and vice versa.

Solution

To convert from tab to space you can use expand

    # convert tab to 4 space in all java files
    find . -name '*.java' ! -type d -exec bash -c 'expand -t 4 "$0" > /tmp/e && mv /tmp/e "$0"' {} \;

To convert all 4 spaces to tab, use unexpand

    unexpand -t 4 <input_file>