The qlmanage tool is a command-line utility in macOS that allows users to interact with the Quick Look framework. Quick Look is a feature in macOS that provides fast, inline previews of various types of files without having to open them in their respective applications. This is particularly useful for developers, system administrators, and power users who need to quickly inspect the contents of files from the Terminal.

Using qlmanage, you can generate previews, test Quick Look plugins, and manage the Quick Look cache. This article will guide you through the essential uses of qlmanage and provide practical examples to help you leverage this tool effectively.

Examples:

1. Generating a Quick Look Preview:
To generate a Quick Look preview of a file, use the following command:

   qlmanage -p /path/to/your/file

For example:

   qlmanage -p ~/Documents/example.pdf

This command will open a Quick Look preview window displaying the contents of example.pdf.

2. Generating a Thumbnail:
You can generate a thumbnail image for a file using the -t option:

   qlmanage -t -s 128 /path/to/your/file

For example:

   qlmanage -t -s 128 ~/Documents/example.pdf

This command will create a thumbnail image of size 128x128 pixels for example.pdf and save it in the current directory.

3. Testing Quick Look Plugins:
If you are developing or testing Quick Look plugins, you can use the -m option to display information about the plugins:

   qlmanage -m

This command lists all the installed Quick Look plugins and their associated file types.

4. Forcing a Quick Look Cache Refresh:
To clear and refresh the Quick Look cache, use the following command:

   qlmanage -r cache

This can be useful if you are experiencing issues with outdated previews or thumbnails.

5. Batch Processing Files:
You can process multiple files at once by specifying a directory:

   qlmanage -p /path/to/your/directory/*

For example:

   qlmanage -p ~/Documents/*

This command will open Quick Look previews for all files in the Documents directory.