Recursively compare directories with summary on different contents without examining file contents’ differences

To see a listing, here are two variants, one that recurses into subdirectories and one that doesn't. All use syntax specific to bash, ksh and zsh.

comm -3 <(cd source && find -type f | sed 's/\.[^.]*$//' | sort) \
        <(cd dest && find -type f | sed 's/\.[^.]*$//' | sort)
comm -3 <(cd source && for x in *; do printf '%s\n' "${x%.*}"; done | sort) \
        <(cd dest && for x in *; do printf '%s\n' "${x%.*}"; done | sort)

Shorter, in zsh:

comm -3 <(cd source && print -lr **/*(:r)) <(cd dest && print -lr **/*(:r))
comm -3 <(print -lr source/*(:t:r)) <(print -lr dest/*(:t:r))

The comm command lists the lines that are common to two files (comm -12), that are only in the first file (comm -23) or that are only in the second file (comm -13). The numbers indicate what is subtracted from the output¹. The two input files must be sorted.

Here, the files are in fact the output of a command. The shell evaluates the <(…) construct by providing a “fake” file (a FIFO or a /dev/fd/ named file descriptor) as the argument to the command.

¹ _{So here the minus sayers are fully justified.}

If you want to perform actions on the files, you'll probably want to iterate over the source files.

cd source
for x in *; do
  set -- "…/dest/${x%.*}".*
  if [ $# -eq 1 ] && ! [ -e "$1" ]; then
    echo "$x has not been converted"
  elif [ $# -gt 1 ]; then
    echo "$x has been converted to more than one output file: " "$@"
  else
    echo "$x has been converted to $1"
  fi
done

Yes, you can do this with GNU find. If your file names don't contain newlines, you can do:

find -printf '%T@ %p\n' | sort -gk1,1

Explanation

• The -printf option of find can print all sorts of information. In this case, we are using:

  %Tk    File's last modification time in the format specified  by
         k, which is the same as for %A.
  @      seconds  since Jan. 1, 1970, 00:00 GMT, with fractional part.
  %p     File's name.
  

  So, %T@ %p\n will print the file's modification time in seconds since the epoch (%T@), a space, and then the file's name (%p).

• These are then passed to sort which is told to sort numerically (-n) on the first field only (-k1,1).

Note that this will return all files and directories. To restrict it to regular files only (no directories, device files, links etc.) add -type f to your find command.

To get human readable dates, you can process the output with GNU date:

find -printf '%T@ %p\t\n' | sort -gk1,1 | 
    perl -lne 's/([^ ]*)//;chomp($i=`date -d \@$1`); print "$i $_"'

Here, the perl command replaces the first string of non-space characters (the date) with itself as processed by GNU date.

The above will fail for file names that contain newlines. To deal with newlines, use:

find -printf '%p\t%T@\0' | sort -zt$'\t' -nk2 | tr '\0' '\n'

That's the same thing except that find will output a \0 instead of \n at the end of each file name. GNU sort can deal with null-separated output so it is still able to sort correctly. The final tr command translates the \0 back to \n.