Using exiftool to write in filename either CreateDate or FileModifyDate, whatever exists

Question

Using exiftool to write in filename either CreateDate or FileModifyDate, whatever exists.

What is the problem: -If no CreateDate exists, error is happening, and filename is not changed according to Creation date.

"Warning: No writable tags set from DSC_0680a.JPG"

How can I tell exiftool to write either CreateDate or FileModifyDate - whatever exists in exif information?

Currently, I am using the following command:

for pic in DSC*.*; do exiftool "-FileName<CreateDate" -d ${pic//.*}_%Y%m%d_%H%M%S.jpg" "$pic"; done;

This does not work too:

exiftool "-FileName<CreateDate" -d "DSC_0680a_%Y%m%d_%H%M%S.jpg" DSC_0680a.JPG  || exiftool "-FileName<FileModifyDate" -d "DSC_0680a_%Y%m%d_%H%M%S.jpg" DSC_0680a.JPG 

Answer 1

Using exiftool in a loop can greatly extend processing time as the startup is its biggest performance hit (see ExifTool Common Mistake #3).

You don't need two separate exiftool commands. You can put both options in the same command and exiftool will use the last valid option (see Note #1 under the -TAG[+-^]=[VALUE] option).

You could use

exiftool "-FileName<FileModifyDate" "-FileName<CreateDate" -d "%%f_%Y%m%d_%H%M%S.%%e" /path/to/files/

and exiftool will fallback on FileModifyDate if CreateDate doesn't exist

Here I did remove the ${pic//.*} and replaced it with exiftool's %f and %e variables, which stand for the Filename and Extension respectively (see the -w (-TextOut) option). When used in a date format string, the percent signs for filename variables need to be doubled.

It should be noted that if used in a Windows Bat file, then all percent signs need to be doubled, which would result in a -d (-dateFormat) string of %%%%f_%%Y%%m%%d_%%H%%M%%S.%%%%e (see ExifTool FAQ #27).

Answer 2

I tried this command with the linux operator "&&", "which means whatever happen to the first command, execute the second one too", and it worked (?).

• The filename that it is changed by the first command,
• it is not changed again from the 2nd command, because,
• it keeps the filename that it was passed from the first command,
• and no more it exists, ecause it changed.

My exiftool command to change / rename filename according to CreateDate OR FileModifyDate that exists in image information tags.

  for pic in DSC*.*;        do exiftool "-FileName<CreateDate" -d  "${pic//.*}_%Y%m%d_%H%M%S.jpg" "$pic"   &&   exiftool "-FileName<FileModifyDate" -d  "${pic//.*}_%Y%m%d_%H%M%S.jpg" "$pic"   ; done;