xmessage

xmessage is a small utility for the X Window System that displays a simple graphical message box. It is used in scripts to alert the user or solicit a basic response without requiring a full GUI application. The program opens a transient window containing a message and one or more buttons, and it waits for the user to click a button.

The message can be supplied on the command line or read from a file using the -file option. The set of buttons can be customized with the -buttons option, where each label can be associated with a numeric return code. The exit status of xmessage corresponds to the return code of the pressed button, enabling scripts to branch on user choice. The -default option can specify which button is activated if the user presses Enter. Other common options include -geometry to position or size the window and -display to select the X server; some versions may also support -timeout to close the dialog after a period of inactivity.

xmessage is part of the X.Org X11 client utilities, typically provided by packages such as xbase-clients or xorg-apps on Linux distributions. It is widely available on systems that run the X Window System, but not on headless environments or Wayland-only configurations unless an X server is present.

See also: zenity, kdialog, xdialog.