Ubuntu – Use case where script filenames have leading numbers to determine execution order

Not sure if this will help as it's not exactly what you're looking for, but you can display the file size under the icon:

1. Open the file explorer
2. Go to places
3. Select preferences
4. Select display tab

http://www.ubuntugeek.com/how-to-tweak-nautilus-to-display-size-of-files-under-their-name.html

However, this is probably a more direct answer to your question: Show current folder size in Nautilus

While your question is tagged with bash, this would be somewhat troublesome ( in my humble opinion ) to use bash for such task. I'd suggest using python because it has a lot of good functions for complex tasks and this answer provides a solution using that language.

Essentially what occurs here is that we use regex to split filenames at multiple delimiters, get only first part and use unique set of those first parts as basenames for new directories.

We then traverse the top directory again , and sort the files in their appropriate places.

The script doesn't do anything spectacular, and actually in algorithm analysis this wouldn't do too well, because of the nested for loops, but for "quick and dirty, yet workable" solution it's alright. If you are interested what each line does, there's plenty of comments added to explain the functionality

Note, the demo only shows printing of the new filenames for testing purpose only. Uncomment the os.rename() part to actually move the file.

The Demo

bash-4.3$ # Same directory structure as in OP example
bash-4.3$ ls TESTDIR
bash-4.3$ # now run script
AAA  AAA.mkv  AAA.nfo  AAA-picture.jpg  BBB  BBB-clip.mp4  BBB.mp4  BBB.srt
bash-4.3$ ./collate_files.py ./TESTDIR
/home/xieerqi/TESTDIR/AAA/AAA-picture.jpg
/home/xieerqi/TESTDIR/AAA/AAA.mkv
/home/xieerqi/TESTDIR/AAA/AAA.nfo
/home/xieerqi/TESTDIR/BBB/BBB.srt
/home/xieerqi/TESTDIR/BBB/BBB.mp4
/home/xieerqi/TESTDIR/BBB/BBB-clip.mp4

Script itself

#!/usr/bin/env python
import re,sys,os

top_dir = os.path.realpath(sys.argv[1])

# Create list of items in directory first
# splitting names at multiple separators
dir_list = [os.path.join(top_dir,re.split("[.-]",f)[0])
            for f in os.listdir(top_dir)
]
# Creating set ensures we will have unique
# directory namings
dir_set = set(dir_list)

# Make these directories first
for dir in dir_set:
    if not os.path.exists(dir):
        os.mkdir(dir)

# now get all files only, no directories
files_list = [f for f in os.listdir(top_dir)
              if os.path.isfile(os.path.join(top_dir,f))
]

# Traverse lists of directories and files,
# check if a filename starts with directory
# that we're testing now, and if it does - move
# the file to that directory
for dir in dir_set:
    id_string = os.path.basename(dir)
    for f in files_list:
        filename = os.path.basename(f)
        if filename.startswith(id_string):
           new_path = os.path.join(dir,filename)
           print(new_path)
           #os.rename(f,new_path)

Additional notes:

• The script can well be adapted to split files at other multiple separators (in the re.split() function): add inside square brackets ( meaning "[.-]") add whatever characters you want.
• The moving part is performed with os.rename() function. Alternatively you could import shutil and use shutil.move() function. See https://stackoverflow.com/a/8858026/3701431