How to list backup files missing corresponding real files?

Question

I accidentally deleted some files spread across my home directory, but I do not know exactly which ones were removed. How can I get a list of all backup files missing their corresponding file? (equivalently, files having names ending with a tilde, without there being another file in the same directory with the same name sans trailing tilde?)

I tried a few things so far; although I don't remember the exact flags, it was something like:

grep -Rlv '(.*)\n\\1~|.*(?!~)'

That didn't work, and neither did:

ls -R | grep -v '(.*)\n\\1~|.*(?!~)'

How can I find these files?

Answer 1

Just find all files with a tilde, remove the tilde and look for the "original":

find . -name '*~' -print0 | while IFS= read -r -d $'\0' file; do 
  [ -e "${file%\~}" ] ||  echo cp "$file" "${file%\~}"; done 
done 

Explanation:

• find ~/ -name '*~' -print0 : find all files in $HOME that end in a tilde and print them with the null (\0) character. The last is necessary to deal with weird file names that contain newlines etc.

• while IFS= read -r -d $'\0' file; : read each file found by find into $file`.

  • IFS= : turns of bash's automatic split at whitespace
  • -r : treat backslashes literally (not as escape characters)
  • -d $'\0' : sets the input field delimiter to the null character.
• "${file%\~}" : removes the tilde, see here
• [ -e "${file%\~}" ] || echo 'cp '$file' '${file%\~}" : the echo will be run only if the file name (sans tilde) does not exist. To actually copy the files, just remove the echo.

Answer 2

In zsh, you can use a glob qualifier to filter matches. The e modifier lets you specify arbitrary code; it's easier on the parsing to write a function and call it with the + modifier.

zsh -c 'deleted () { ! [ -e ${REPLY%\~} ] }; ls -ld **/*~(+deleted)'

If zsh isn't available, you can use find.

find ~ -name '*~' -type f -exec sh -c '[ -e "${0%\~}" ] && ls -ld "$0"' \;

or, faster:

find ~ -name '*~' -type f -exec sh -c 'for x; do [ -e "${x%\~}" ] && ls -ld "$x"' _ {} +

Answer 3

An alternative method to using find. Cache both lists of files (stripping "~") and diff the two anonymous named pipes storing each set.

diff <(ls -R *[^~] | xargs -n 1 readlink -f)  <(ls -R *[~] | xargs -n 1 readlink -f | sed 's/~$//')