Rename Files Without Extension

Hi Paul,

The original post is here — for image validation on files with extensions.

The original script that I wrote last Fall was used to validate files with extensions to their actual image type. It won't work with files without extensions, and neither will the UNIX file command, or even Spotlight's mdls utility that thinks image files without extensions are just public.data.

There are no tools available in macOS that can explore the internal image data, and arrive at the accurate extension information — except the third-party exiftool which you indicated was installed last Fall. Am I correct that your current images without extensions are only camera RAW images that may be RAF, CR2, or DNG image types?

This morning, using the same image data as last Fall, I wrote and tested a very short (8 lines) Zsh script that recursively retrieves all subordinate images of a parent directory and uses exiftool to peek inside them for their FileType. This is also the uppercase extension from the first paragraph that should be assigned to the raw image, and I use that in the renaming. When tested against the same images as I used last Fall for your other solution, the renaming was 100% accurate using known raw files.

You can run this script from the Terminal after making it executable. I have a Test4 directory on my Desktop. Do not use tilde path shorthand, as Zsh doesn't expand tilde without additional help:

cd Desktop
chmod +x addext.zsh
./addext.zsh ./Test4
Script has completed.

Copy and paste the following into BBEdit (which you also installed last Fall), and then save on your Desktop as addext.zsh.

#!/bin/zsh

: <<'COMMENT'

Recursively drill into directory hierarchy for image files with no
extension. Exclude text files. Use exiftool to inspect the image
and extract FileType (extension), then rename with that extension.

Requires third-party exiftool installation.

Usage: addext.zsh /path/to/parent/directory

VikingOSX, 2020-05-22, Apple Support Communities, No warranties of any kind.

COMMENT

STARTDIR="$1:a"
setopt extended_glob
for f in ${STARTDIR}/**/*~*.txt(.N);
do
    # print "${f}"
    EXT=$(/usr/local/bin/exiftool -s3 "-FileType" "${f}")
    mv "${f}" "${f}.${EXT}"
done
echo "Script has completed."

Before:

After:



Try using the file command on the files. I believe that that will try to determine the type of file even if the suffix is missing.

BradleyRossMacBook:Pictures bradleyross$ cp gingeravatar2.jpg working/gingeravatar

BradleyRossMacBook:Pictures bradleyross$ cd working

BradleyRossMacBook:working bradleyross$ file *

gingeravatar: JPEG image data, JFIF standard 1.01, resolution (DPI), density 72x72, segment length 16, Exif Standard: [TIFF image data, big-endian, direntries=5, orientation=upper-left, xresolution=74, yresolution=82, resolutionunit=2], baseline, precision 8, 143x136, components 3

BradleyRossMacBook:working bradleyross$ 

The --extension of the file command gives the allowed suffixes. (See man file)

BradleyRossMacBook:working bradleyross$ file --extension *

gingeravatar: jpeg/jpg/jpe/jfif

BradleyRossMacBook:working bradleyross$ 

Thanks Paul. Yeah I don't want to work with that. Seems complicated but that's only because I didn't write it.

In the interim, could you please do the following?

Open Terminal and copy / paste (do not type) the following:

file -I 

There needs to be a single space character after the last character, which is the reason to copy / paste.

Then, drag an image file icon into the Terminal window. Don't press Return just yet.

Then, copy / paste

 | perl -F/ -lane 'print $F[-1]' | awk '{print $1}' | sed 's/.$//'

... after which you can finally press Return.

You will get output resembling the following, using a .pdf as an example:

iMac22:~ john$ file -I /Users/john/Desktop/test.pdf | perl -F/ -lane 'print $F[-1]' | awk '{print $1}' | sed 's/.$//'
pdf
iMac22:~ john$ 

For a .png example:

iMac22:~ john$ file -I /Users/john/Desktop/test.png | perl -F/ -lane 'print $F[-1]' | awk '{print $1}' | sed 's/.$//'
png
iMac22:~ john$ 

Repeat for each type of file that you need to rename (.raf .dng .cr2).

This assumes you have a representative copy of each of those three file types. I don't happen to have any which is the reason you need to test the above. Include other image file types if you need to rename them also.

Confirm that the results of the above script will be the file extensions you want to append.

If it is, perhaps I can come up with a script. Maybe it will even work. No promises. As you can see from the above awful hideous attempts to extract something as simple as a file type it is certain to be an ugly mess so just be sure you have that backup 😮

1. Is your exiftool installed in /usr/local/bin?
2. On the Run Shell Script action, is the Pass input setting as arguments?
3. When you run this Automator Application, do you just click on the containing folder, or click inside it, for the initial selection?

That /usr/local/bin/lib/image is a non-standard location for an exiftool installation. For now, just replace the /usr/local/bin/exiftool path in the script with /usr/local/bin/lib/image/exiftool — so the script can find it. It was also important that you changed Pass input to as arguments. With those two changes, the Automator application should work now.

Good.

If you encounter any more of those rename failures ending in a period, it is because the associative array does not have an entry in it for the particular image extension, and the key lookup fails. These need to be entered in pairs (e.g. raf RAF, crw CRW, etc.). ExifTool will work with an extensionless filename to show you the real FileTypeExtension that should be on the image.

for file in * ; do mv "$file" "$file.jpg" ; done

I suggest you start with a limited selection of duplicate files first because the above script is not undoable.

A safer alternative is to copy them as follows:

for file in * ; do cp "$file" "$file.jpg" ; done

... then sort by kind and delete the duplicates.

Errata. In case there are any images that already have an extension, we need to test for that, and ignore them. The following change provides that extra precaution to avoid redundantly adding to an existing extension. Update this code segment in the previously provided script:

    EXT=$(/usr/local/bin/exiftool -s3 "-FileType" "${f}")
    # skip those files that already have an extension
    [[ ${f:e} ]] && continue
    mv "${f}" "${f}.${EXT}"



Post the script's contents here if you wish. Hopefully it's not too long. I did attempt to get VikingOSX's attention so be patient.

Paul,

I will look into this in the morning. If I recall the original problem, you had a mix of images that could be raw, tiff, or jpg, and the script had to poke at the image file to determine its true identify before it could be renamed.

I haven't forgotten about you Paul. Since if-then loops are unwieldy in bash I spent a lot of time attempting to incorporate my idea into a more readable AppleScript but got frustrated because the AppleScript "do shell script" command isn't doing what I would like it to do.

In case you're interested what I'd like to do is pass the file name to

file -I /Volumes/PR_500/image_file | perl -F/ -lane 'print $F[-1]' | awk '{print $1}' | sed 's/.$//'

.... which returns a nicely truncated jpg or png or whatever that could simply be appended to that file name, but getting the file name (image_file in the above) is proving to be difficult.

I would prefer an AppleScript but may abandon that line of thought and just go back to a bash one-liner.

I cannot find the post to be able to look at the discussion thread...

VikingOSX probably remembers it but if you're a glutton for punishment you could use this site's Search function, which is capable of finding Discussions using "Search by author". Be advised Search is horrendously broken and has been that way for so long that I doubt it will ever be fixed. I attempted to find what you're looking for but I can only take so much abuse.