linux-shell: renaming files to creation time

Question

Good morning everybody,

for a website I'd like to rename files(pictures) in a folder from "1.jpg, 2.jpg, 3.jpg ..." to "yyyymmdd_hhmmss.jpg" - so I'd like to read out the creation times an set this times as names for the pics. Does anybody have an idea how to do that for example with a linux-shell or with imagemagick?

Thank you!

Answer 1

Naming based on file system date

In the linux shell:

for f in *.jpg do     mv -n "$f" "$(date -r "$f" +"%Y%m%d_%H%M%S").jpg" done 

Explanation:

• for f in *.jpg do

  This starts the loop over all jpeg files. A feature of this is that it will work with all file names, even ones with spaces, tabs or other difficult characters in the names.

• mv -n "$f" "$(date -r "$f" +"%Y%m%d_%H%M%S").jpg"

  This renames the file. It uses the -r option which tells date to display the date of the file rather than the current date. The specification +"%Y%m%d_%H%M%S" tells date to format it as you specified.

  The file name, $f, is placed in double quotes where ever it is used. This assures that odd file names will not cause errors.

  The -n option to mv tells move never to overwrite an existing file.

• done

  This completes the loop.

For interactive use, you may prefer that the command is all on one line. In that case, use:

for f in *.jpg; do mv -n "$f" "$(date -r "$f" +"%Y%m%d_%H%M%S").jpg"; done 

Naming based on EXIF Create Date

To name the file based on the EXIF Create Date (instead of the file system date), we need exiftool or equivalent:

for f in *.jpg do     mv -n "$f" "$(exiftool -d "%Y%m%d_%H%M%S" -CreateDate "$f" | awk '{print $4".jpg"}')" done 

Explanation:

The above is quite similar to the commands for the file date but with the use of exiftool and awk to extract the EXIF image Create Date.

• The exiftool command provides the date in a format like:

  $ exiftool -d "%Y%m%d_%H%M%S"  -CreateDate sample.jpg Create Date                     : 20121027_181338 

  The actual date that we want is the fourth field in the output.

• We pass the exiftool output to awk so that it can extract the field that we want:

  awk '{print $4".jpg"}' 

  This selects the date field and also adds on the .jpg extension.