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linuxbashtouch

Change modification date to filename

I've got a number of files of which I want to change the modification date in linux. The modification date is saved in the filename.

So I've got files, whose name is for example "IMG_20180101_010101.jpg", but the modification date is today. I want to change the modification date to 2018-01-01 01:01:01, as in the filename. I've tried with find and touch:

find . -iname 'IMG*' -print | while read filename; do touch -t {filename:7:8} "$filename"; done

When I do this I always get an error ("invalid date format: {filename:7:8}).

What am I doing wrong?

Solution

  • If you want to set the file timestamp according to the filename, you can try this:

    find -type f -name "IMG_*" -exec bash -c 'touch -t $(sed "s/.*IMG_\([0-9]\{8\}\)_\([0-9]\{4\}\)\([0-9]\{2\}\).jpg$/\1\2.\3/" <<< "$1") "$1"' _ {} \;

    As mentionned in the touch man page, the option -t expects a format [[CC]YY]MMDDhhmm[.ss]. That's the purpose of the sed command.