Opening files and pages

The open command views a file or web page in a new tab:

open diagram.png              image, in an image tab
open notes.md                 Markdown, rendered in a markdown tab
open https://example.com      web page, embedded in a page tab
open page example.com         same, for a bare address

Full form: open [external] [page] <target>. Relative paths resolve against the tab's working directory. What kind of tab you get depends on the file type — see Image viewer, Markdown preview, and Embedded web pages. Every tab it opens joins the current tab's group and can be closed from the strip with its × button.

Targets with an http:// or https:// scheme are treated as web addresses; the page keyword forces web interpretation and assumes https:// for a bare address like example.com. Anything else is a file path. Only http and https pages can be opened — other schemes are rejected as invalid.

Opening outside the app: open external

open external <target> hands the target to the operating system instead of opening a tab:

open external photo.jpg           the OS image viewer (Preview on macOS)
open external https://example.com the OS default browser

Wildcards

A path with shell wildcard characters opens every matching file, up to 10 at a time:

open shots/*.png

The pattern expands exactly as your shell would expand it. Past 10 matches, the first 10 open and a note reports how many matched in total. A pattern matching nothing reports that too. Wildcards only apply to file paths, never web addresses.

Errors

Mistakes are reported in the current tab before anything opens:

• A malformed invocation prints the usage line: open [external] [page] <target>.
• A file that doesn't exist gets a not-found message.
• A file type with no viewer is reported as unsupported.
• A malformed or non-http(s) address is reported as invalid.