Ubuntu – Run command recursively through subdirectories

bashscripts

I am trying to convert a bunch of images to thumbnails that might be in several subdirectories, and save a copy of the image as a thumbnail inside the subdirectory, but I can't figure out the syntax. Any advice would be welcome.

convert test/*/*.jpg -50x50 test/*/*_thumb.jpg

Best Answer

You should use find for finding all files you need.

find test -iname *.jpg -exec convert {} -resize 50x50 {}_thumb \;

And then you should rename files with name *.jpg_thumb to *_thumb.jpg by using:

find -name *.jpg_thumb -exec rename -e 's/^(.*)(.jpg)(_thumb)$/\1\3\2/' '{}' \;

Note that -50x50 is not a legal parameter for convert. You should use -resize parameter with value 50x50 like in example above.

Related Solutions

Ubuntu – Creating a new subdirectory in multiple existing directories

You can do it without a loop:

mkdir -p Week{1..15}/Assignments

Batch Rename Multiple Image Types with Scripts

Below a python solution (script).

The script uses the imghdr module to recognize the file type. It will add the correct file extensions (if missing), of the following types:

rgb, gif, pbm, pgm, ppm, tiff, rast, xbm, jpeg, bmp, png

If the file already has a file extension, it will be skipped. In case the file is of an unknown file type (if it is damaged for example), the file is reported as "could not determine":

could not determine: /home/jacob/Bureaublad/picturetest/blub

The script:

#!/usr/bin/env python3

import os
import imghdr
import shutil

directory = "/path/to/pictures"

for name in os.listdir(directory):
    # combining file+its directory:
    file = directory+"/"+name
    # only files without a dot are subject to renaming (else the file already has a file extension or is a hidden file):
    if name.count(".") == 0:
        # fetch the file extension from the file:
        ftype = imghdr.what(file)
        # if it is impossible to get the extension (if the file is damaged for example), the file(s) will be listed in the terminal window:
        if ftype != None:
            shutil.move(file, file+"."+ftype)
        else:
            print("could not determine: "+file)

Paste it into an empty file, save it as rename.py, set the directory to the pictures in the directory = "/path/to/pictures" -line and run it by the command:

python3 /path/to/rename.py

Rename recursively

In case your images are not in a "flat" directory, but in a layered directory, use the version below. It will check (and repair if necessary) file extensions inside the file's current folder.

#!/usr/bin/env python3

import os
import imghdr
import shutil

directory = "/path/to/pictures"

for root, dirs, files in os.walk(directory):
    for name in files:
        file = root+"/"+name
        if name.count(".") == 0:
            ftype = imghdr.what(file)
            if ftype != None:
                shutil.move(file, file+"."+ftype)
            else:
                print("could not determine: "+file)