The qlmanage command is a powerful utility on macOS used to interact with the QuickLook server. It allows developers and users to generate previews, manage thumbnails, and control the QuickLook generation process directly from the command line.

Display QuickLook Previews

You can use qlmanage to display QuickLook previews for one or multiple files. This is useful for quickly inspecting file content without opening the associated application.

# Display QuickLook for one or multiple files:
qlmanage -p filename filename2

Generate Thumbnails

qlmanage can compute thumbnails for various file types. This command is particularly handy for batch processing images or other media files to create preview images.

# Compute 300px wide PNG thumbnails of all JPEGs in the current directory
# and put them in a directory:
qlmanage *.jpg -t -s 300 path/to/directory

Reset QuickLook Server

If the QuickLook generation process encounters issues or you need to refresh its state, you can reset the QuickLook server using the -r flag.

# Reset Quicklook:
qlmanage -r

Understanding qlmanage Options

The qlmanage command offers several options to customize its behavior. The -p flag is used for previewing, -t for generating thumbnails, -s to specify thumbnail size, and -r to reset the server. Understanding these options allows for efficient management of QuickLook previews on macOS.

External Resources

• Apple QuickLook Framework Documentation
• Stack Exchange: qlmanage Questions