Triggers

A trigger is an action that is performed when text matching some regular expression is received in a terminal session.

How to Create a Trigger

To create a trigger, open the Preferences panel. Select the Profiles tab. Choose the profile to which you wish to add a trigger. Then select the Advanced tab. Click the Edit button in the Triggers section. A panel opens that displays any existing triggers. You can click the + button to add a new trigger.

Triggers have a regular expression, an action, an optional parameter, and may be marked as Instant.

Regular Expression

Regular expressions conform to the ICU regular expressions rules. Text that is written to the screen including the BEL control code are sent to the regex matcher for evaluation. Only one line at a time is matched. By default, matching is performed when a newline or cursor-moving escape code is processed. If a line is very long, then only the last three wrapped lines are used (that is, the last three lines as seen on the display). This is done for performance reasons. You can change this limit in Advanced Preferences > Number of screen lines to match against trigger regular expressions.

Actions

The following actions are available:

• Annotate: Attaches text to the matched region as an annotation.
• Bounce Dock Icon: Makes the dock icon bounce until the iTerm2 window becomes key.
• Capture Output: Save the line to the Captured Output toolbelt tool. See Captured Output. The parameter is text to send (as though it had been typed) when you double-click on an entry in the Captured Output tool.
• Highlight Text: The text matching the regex in the trigger will change color. The parameter sets the color.
• Invoke Script Function: Runs a script function. The parameter is always an interpolated string. See Scripting Fundamentals for details.
• Make Hyperlink: Converts the matched text into a hyperlink with the provided URL as its target.
• Open Password Manager: Opens the password manager. You can specify which account to select by default.
• Post Notification: Posts a notification with Notification Center.
• Prompt Detected: Informs iTerm2 that the shell prompt begins at the start of the match. Used to emulate Shell Integration features. If the prompt is one line long then use Instant.
• Report Directory: Tells iTerm2 what your current directory is. You can use this to enable Shell Integration features without installing the scripts. The parameter is your current directory.
• Report User & Host: Tells iTerm2 what your user or host name is. You can use this to enable Shell Integration features without installing the scripts. To specify just a user name, say user@. For just a host, say @host. For both, say user@host.
• Ring Bell: Plays the standard system bell sound once.
• Run Command: Runs a user-defined command.
• Run Coprocess: Runs a Coprocess.
• Run Silent Coprocess: Runs a silent Coprocess. This differs from a coprocess in that output goes only to the coprocess and does not get displayed while it is running.
• Send Text: Sends user-defined text back to the terminal as though the user had typed it.
• Set Mark: Sets a mark. You can specify whether you'd like the display to stop scrolling after the trigger fires.
• Set Title: Sets the session's title.
• Show Alert: Shows an alert box with user-defined text.
• Stop Processing Triggers: When this action is invoked no triggers further down the list will be invoked for the current text.

Tricks

If you'd like to match more text than you highlight with the Highlight Text trigger, you can use look-behind and look-ahead assertions. Suppose you want to highlight the word "ipsum" only when it occurs in the phrase "lorem ipsum dolor". Then you would use this regex:

(?<=lorem )ipsum(?= dolor)

Parameter?

Various actions (Run Command, Run Coprocess, Post Notification, Send Text, and Show Alert) require additional information. This is specified in the "Parameters" field. When the paramter is a text field with freeform entry, some special values are defined. The interpretation of the parameter depends on whether Use interpolated strings for parameters (at the bottom of the Triggers window) is enabled.

When Use interpolated strings for parameters is off:

Regardless of the Use interpolated strings for parameters setting:

When Use interpolated for parameters is on, a local variable named matches is declared. It is an array. Its first value (matches[0]) gives the entire matched text. Subsequent values of matches[1], matches[2], etc., give capture groups. For example, the following parameter expands to the first capture group:

\(matches[1])

Instant

When Instant is set, the trigger will fire once per line as soon as the match occurs, without waiting for a newline. This was added for the benefit of the Open Password Manager trigger, since password prompts usually are not followed by a newline. This may cause certain regular expressions (for example, .*) to match less than they otherwise might. Instant triggers only fire once per line, except for the Highlight action.

Use interpolated strings for parameters

Prior to version 3.3 of iTerm2, parameters could use backreferences like \1 to refer to a capture group in the regular expression. This remains the default for triggers for backward compatibility. As of version 3.3, interpolated strings became the standard way to handle strings with embedded references. By enabling the Use interpolated strings for parameters settings you can use the more powerful interpolated string syntax for your triggers' parameters. See the Scripting Fundamentals document for more details on interpolated strings.

Example

The iTerm2-zmodem project demonstrates hooking up iTerm2 to zmodem upload and download.