exiftool

exiftool is a powerful, flexible, and cross-platform Perl library and command-line application for reading, writing, and editing meta information in a wide variety of files. Developed by Phil Harvey, it supports many different metadata formats including Exif, IPTC, XMP, GPS, ID3, Photoshop IRB, FlashPix, ICC Profile, MIE, and many manufacturer-specific MakerNotes.

It can process numerous file types such as images (e.g., JPEG, TIFF, PNG, DNG, RAW formats), video (e.g., MOV, MP4, AVI, MPEG), audio (e.g., MP3, WAV), and various document formats (e.g., PDF, DOC, XLS). ExifTool is widely used by photographers, archivists, digital forensics specialists, and developers for tasks like extracting detailed technical information, geotagging photos, correcting timestamps, removing sensitive data, or synchronizing metadata across different files. Its ability to handle complex nested data structures and perform batch operations efficiently makes it an indispensable tool for managing digital assets. It automatically creates backup files (e.g., filename_original) when modifications are made, ensuring data safety.

While powerful, exiftool operates directly on file metadata. By default, it creates backup copies (e.g., filename_original) before modification, but the use of the -overwrite_original option can permanently alter or destroy original data without a backup, so it must be used with extreme caution.

The extensive number of supported tags and options can present a steep learning curve for new users. As it's a Perl script, it requires a Perl interpreter, which is generally available on Linux distributions.

To simply view all metadata in a file, run exiftool filename.ext.
To view specific tags, specify them: exiftool -creatordate -model image.jpg.
Adding options like -G will show the group for each tag, and -s will provide a short output format.

To write or modify a tag, use the -TAG=VALUE syntax: exiftool -comment="My new comment" file.jpg.
Multiple tags can be written in a single command: exiftool -artist="John Doe" -copyright="© 2023 J. Doe" photo.jpg.
To remove a tag, assign an empty string: exiftool -keywords= image.png.

ExifTool can process multiple files or entire directories recursively.
To process all JPEG files in the current directory: exiftool *.jpg.
To process all files in a directory and its subdirectories: exiftool -r ./path/to/directory/.
This allows for efficient bulk modification of metadata.

ExifTool was created and is actively maintained by Phil Harvey. Its initial public release was in 2003. Written entirely in Perl, it quickly gained popularity due to its comprehensive support for various metadata formats, cross-platform compatibility, and robust feature set. Over the years, it has become a de-facto standard for metadata manipulation, continuously updated to support new cameras, file formats, and metadata standards.

identify(1) (from ImageMagick) - A tool to describe the format and characteristics of one or more image files., file(1) - Determine file type., mediainfo(1) - Display technical and tag data for audio/video files., exiv2(1) - A C++ library and command-line utility to manage Exif, IPTC, and XMP metadata., jhead(1) - A command line program to manipulate EXIF data in JPEG files., ffprobe(1) (from FFmpeg) - Multimedia stream analyzer, useful for video/audio metadata.