ExiftoolNotInstalled error when trying to remove EXIF data

[kiskoza]

Hi. I'm trying to remove some sensitive information (e.g.: GPS location) from uploaded files using exiftool.

When I try to check the existing EXIF data, it works:

Exiftool.new(file_path, '-ignoreMinorErrors').to_hash
# {
#   "source_file": "image_with_gps.jpg",
#   "exif_tool_version": 11.88,
#   "file_name": "image_with_gps.jpg",
#   "file_size": "6.0 MB",
#   ...
# }

However, as soon as I try to change something in the file it starts complaining that exiftool is not installed

Exiftool.new(file_path, '-ignoreMinorErrors -gps:all= "-gps*=" -tagsfromfile @ -Orientation')
# Exiftool::ExiftoolNotInstalled raised

The problem seems to be with the lines checking that the result of the exiftool command is an empty string: lib/exiftool.rb#L58-L60.

1. Is this gem meant to be used for manipulating EXIF data? If no, is there one that you can recommend?
2. Is there any additional exiftool option I need to add to keep my command compatible with this gem?

I would help creating a PR to make my use-case viable if you're interested in it

[morozgrafix]

Thank you for opening an issue. I believe that both exiftool.rb and exiftool_vendored.rb were intended as utilities to read exif data from files and not manipulate the files. I'm able to reproduce the issue that you've described. I will dig a little bit more into it in the next week. Meanwhile one of the workarounds would be to call built in Ruby Kernel methods with a -q flag for example (of course depending on the desired output you want to return).

Something along those lines with verbose output:

irb(main):008:0> %x{ exiftool path/to/test.jpg -gps:all= "-gps*=" -tagsfromfile @ -Orientation }
=> "    1 image files updated\n"

or with a -q quiet flag and a system call

irb(main):009:0> system('exiftool path/to/test.jpg -gps:all= "-gps*=" -tagsfromfile @ -Orientation -q')
=> true

And of course improvement PRs are always welcome.