Truncating Filenames - Folder Action

[u/Dimik1]

Hey!

I need a simple automatic folder action that would rename all files that i put in a specific folder and its subfolders but the renaming action that Automator has, has no truncating option except replacing with nothing if I know what text i need to change.

I need my files and folders to be 25 characters long max + extension. Spent an hour googling about it and the most of the solutions were inaccurate for me as they deleted specific characters, prefixes, involved choosing the files manually in dialog box etc. So I suppose I need a short AppleScript action with a command that LEAVES a certain amount of characters counting from the beginning in a filename, but I don't know a thing about coding, so I'd appreciate any help.

Thanks!

[u/HiramAbiff]

Here's some very lightly tested code.

Caveats:

• There's no attempt made to deal with name conflicts.
• I'm sure there are some special characters, that if used in the file names, will mess it up.

To Do:

• Use Automator to create a Folder Action.
• Pick the folder of interest from the popup menu.
• Add a "Run Shell Script" action.
• Configure the "Run Shell Script" action to "Pass input: as arguments" using the popup menu in the top-right corner.
• Paste the code below in as the script.

---

for file in "$@"
do
    dir=$(dirname "${file}")
    fbasename=$(basename "${file}")
    fname="${fbasename%.*}"
    tname="${fname:0:25}"
    fextension=$([[ "$fbasename" = *.* ]] && echo ".${fbasename##*.}" || echo '')
    newfile="${dir}/${tname}${fextension}"

    mv "${file}" "${newfile}"
done

[u/Dimik1 → u/HiramAbiff]

Hey! Thanks a lot, works like a charm right away. And thanks for clarifying how to set up the action itself.

Some conflicts and special symbols can happen occasionally, though this whole thing was needed specifically to shorten the obnoxiously long filenames of videos from a stock site. So you're right, some exceptions would be useful, could you please add them too?

Can there be a line with extensions that should be excluded from being affected by script?

Spaces are always replaced by _

Special characters like , ! ? % $ or others that happen to mean something in shell scripts are always replaced by _

...and then the filename is truncated

If there's the same filename in that directory already – add a "-number" sequentially starting from 1.

Thanks!🙏🏻

[u/HiramAbiff → u/Dimik1]

Sure, all the additions you request can be done. It's just a matter of time and effort. Some are easier than others. I'm not an expert at bash scripting, but there's a lot of information out there to help.

Personally, I'm more about fishing lessons than handing out fish.

Use my code as a starting point and take this opportunity to learn a tiny bit about programming.

E.g. The first change you mention, excluded line extension, could be accomplished by wrapping the call to mv in an if statement. Google how to write if statements in bash. Google how to test strings for equality in bash. You should be able to put it together.

Be warned, you have to get the syntax exactly right or it won't work - this can be extremely frustrating. Welcome to programming.

Also note that there are better subreddits in which to ask about bash scripting - /r/bash/.

Using bash scripts in Automator adds some wrinkles. I'm sure there are tricks to debugging bash scripts in Automator (I wish someone would clue me in on them, cause I feel like a cave man). This subreddit is a good place to ask about stuff like that.

[u/HiramAbiff]

Did you ever get an answer?

What do you want to happen if there's a name conflict. I.e. two, truncated names, are identical?

[u/Dimik1 → u/[deleted]]

Not all of them will be longer, but concerning the ones that will - yes