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Chad--24216
Asked: 2012-07-03 11:02:08 +0800 CST

How do I change the Creation/Mod Date of all folders on a USB drive using Touch command?

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I've got a USB drive with mp3 music on it that I play in my car. My car has a USB drive port. Problem is that the car sorts the music by Creation/Modification Date (and not alphabetically). This makes it a pain to find what artist I'm looking for.

To solve this problem, I need a way to "update" the Creation/Modification Date for all folders on the USB drive every time I add a new folder of music to the USB drive. Anyone know how I can do this?

The Touch command works great, but the format touch <filename> would take forever to do on each folder on the drive. Anyway to select all folders on the drive and then touch <all folders>?

On my USB drive I have a folder for each album and the songs within each respective folder, like so: Album-1-folder Album-2-folder

I need to apply the Touch command to each of the "album" folders on the drive.

I stumbled upon a simple solution to solve this issue:touch /media/USB_Drive/*

command-line

3 Answers

  1. If you have a lot of files to touch, it's just going to take a while. You can plug-in the drive, and in a terminal, assuming your drive is mounted as /media/USB_DISK, do the following:

    for i in `find /media/USB_DISK -type d|sed -e 's/ /%20/g'|sort`; do
   echo $i|sed -e 's/%20/\\ /g'|xargs touch
done

    Just replace the USB_DISK with the proper name of the folder where your drive is mounted under the /media/ directory.

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  2. Even if you get that to work, all files would have the same date. It doesn't sound like that would help.

    What would work is a script that has hard-coded file names. Hard-coding the file names is necessary to create your preferred order. Just "touching" them in the preferred order will "create" your order, so you don't need to enter actual dates into the touch command.

    #!/bin/bash

cd /path/to/folder1
touch file1
sleep 1
touch file4
sleep 1
touch file2
sleep 1
touch "file 5 with spaces"

cd /path/to/folder2
touch file9
sleep 1
touch file3
sleep 1

    The "sleep" commands are needed to force each "touch" to have a different time. Note that the file "numbers" don't matter, and are processed out of numerical order. The order in the script, however, creates the "processing" order.

    Note that you will need to update and run your script every time you add new songs/files.

    Edit: I just saw the "sorted find" post. That would probably work better. :)

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  3. Dobey's answer is on the right track, but it will fail if any directory name contains a space. In general, it's not a good idea to use the output of find in a script for the same reason that the output of ls shouldn't be parsed by a script: File names can easily contain characters which make it difficult or impossible for a script to accurately interpret.

    There are several options here. One is to use the -print0 switch to find combined with an appropriate call to xargs. See the respective man pages for details.

    The approach I'm recommending is simpler for the specific problem at hand and uses shell globing to get accurate file names:

    for i in /media/USB_Drive/*; do
  [[ -d "$i" ]] || continue   # skip non-directories
  echo "touching $i..."
  touch "$i"
done

    Note that using a glob automatically results in an alphabetized list.

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