Bash Script to Sort Files into Alphabetical and Numbers Folders (offset the sorting letter to the 8th character)

Question

eg file name: 9323 - Unix.ext or z223 - 50 Cent.ext

I would like to know how to sort all the files in the current directory into ./A and ./B etc.. and ./Numbers but using the 8th character in the filename as the comparison variable.

'U' and '5' would be the variable to sort by from the example above.

Thank you

Answer 1

rename  -n 'if (-f $_) {
   my $c=substr($_,7,1);
   if ($c) {
     mkdir $c unless (-d $c);
     $_="$c/$_" if (-d $c);
   };
}' *.ext

This uses the perl rename command (also known as prename and file-rename), NOT to be confused with the rename command from util-linux which has completely different and incompatible command line options.

The script iterates over all files on the command line (or read from STDIN) and if the current file is a regular file (i.e. not a directory, named pipe, socket, etc) then it:

• extracts the 8th character using the substr() function into variable $c. substr offsets start from 0, so the ,7,1 refers to the 8th character.
• if $c isn't empty (which will happen with short filenames), it:
  • makes the directory $c if it doesn't exist.
  • renames the current file into that directory if it is a directory (i.e. doesn't break if $c already exists but isn't a directory)

Alternatively, the script could move files into a directory called, e.g., Misc if $c is empty:

rename -n 'if (-f $_) {
   my $c=substr($_,7,1);
   $c="Misc" unless ($c);
   mkdir $c unless (-d $c);
   $_="$c/$_" if (-d $c);
}' *.ext

Note: both examples above use rename's dry-run option (-n). They will only show what the files would be renamed/mv-ed to if you let it. When you're satisfied that the rename scrript will do what you want, remove the -n option (or replace it with -v for verbose output).

e.g.

$ rename -v  'if (-f $_) { my $c=substr($_,7,1);  $c="Misc" unless ($c) ; mkdir $c unless (-d $c); $_="$c/$_" if (-d $c)}'  *
9323 - Unix.ext renamed as U/9323 - Unix.ext
foo.ext renamed as Misc/foo.ext
z223 - 50 Cent.ext renamed as 5/z223 - 50 Cent.ext