Bash input problem after computing size of folder with du for pv when gpg prompts user

Question

I'm working on a script to cipher a bunch of folders through the use of tar, gzip and gpg, plus pv with du and awk to keep track of progress. Here is the line that causes problems

tar cf - "$f" | pv -s $(($(du -sk "$f" | awk '{print $1}') * 1024)) | gzip | gpg -e -o "$output/$(basename "$f").tar.gz.gpg"

This works well most of the time. However, if the output file already exists, gpg prompts the user, asking if we want to override the file or not. And in this case, when the script exits, the console kind of breaks: what I type does not appear anymore, pressing Enter does not create a new line, and so on.

The problem does not appear if the outfile does not exist yet, nor if the -s option of pv is missing or computed without du and awk (ex: $((500 * 500)). This won't break the console, but obviously the progress bar would be completely off)

The problem is reproducable even by using this command line outside of a script and replacing $f and $output with desired options.

Answer 1

Perhaps one or a combination of these changes will help.

1. Change the gpg command to write to stdout, redirected to the file you want: gpg -e -o - > "$output/$(basename "$f").tar.gz.gpg".
2. Calculate the file size with stat: stat -c "%s" "$f".

The whole line might then look like this:

tar cf - "$f" | pv -s $(stat -c "%s" "$f") | gzip | gpg -e -o - > "$output/$(basename "$f").tar.gz.gpg"