---
name: "tkwait"
section: "n"
platform: "macos"
package: "tcl"
version: "152"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/tkwait/n"
---

# tkwait(n)

Wait for variable to change or window to be destroyed

## NAME

tkwait - Wait for variable to change or window to be destroyed

## SYNOPSIS

**tkwait variable** *name*

**tkwait visibility** *name*

**tkwait window** *name*

## DESCRIPTION

The **tkwait** command waits for one of several things to happen, then it returns without taking any other actions. The return value is always an empty string. If the first argument is **variable** (or any abbreviation of it) then the second argument is the name of a global variable and the command waits for that variable to be modified. If the first argument is **visibility** (or any abbreviation of it) then the second argument is the name of a window and the **tkwait** command waits for a change in its visibility state (as indicated by the arrival of a VisibilityNotify event).  This form is typically used to wait for a newly-created window to appear on the screen before taking some action. If the first argument is **window** (or any abbreviation of it) then the second argument is the name of a window and the **tkwait** command waits for that window to be destroyed. This form is typically used to wait for a user to finish interacting with a dialog box before using the result of that interaction.

While the **tkwait** command is waiting it processes events in the normal fashion, so the application will continue to respond to user interactions. If an event handler invokes **tkwait** again, the nested call to **tkwait** must complete before the outer call can complete.

## KEYWORDS

variable, visibility, wait, window