gdm-binary

View documentation for the original command

$ tldr gdm

gdm-binary
This executable is typically launched automatically by the system's init process (e.g., systemd) when the graphical target is reached, and is not intended for direct user invocation with command-line options.

gdm-binary is the actual executable daemon that powers the GNOME Display Manager (GDM).
GDM is responsible for providing the graphical login screen (often called the 'greeter'), allowing users to log in, select their preferred desktop environment (such as GNOME, Xfce, or KDE), and manage user sessions.
It typically starts automatically at boot time, primarily managed by systemd or a similar init system, and runs as a background service.
Users rarely, if ever, interact with gdm-binary directly, as its behavior and appearance are configured through specific system-wide configuration files rather than command-line arguments.
As a core component of the graphical environment, gdm-binary manages display servers (like X.Org or Wayland), handles multiple concurrent user sessions, and ensures a smooth transition from the login prompt to the user's desktop.

The gdm-binary executable is not intended for direct user execution.
It is an internal system component typically launched and managed by the system's init process (e.g., systemd).
Attempting to run it manually can lead to conflicts with the active display manager, display issues, or system instability.
Configuration of GDM's behavior and appearance is primarily achieved by editing its dedicated configuration files (e.g., /etc/gdm3/custom.conf), not through command-line parameters to gdm-binary itself.

The behavior and appearance of GDM are controlled by configuration files, most notably:
/etc/gdm3/custom.conf or /etc/gdm/custom.conf: This is the primary user-editable configuration file for customizing GDM's behavior, such as default sessions, automatic login, and Xserver settings.
/usr/share/gdm/gdm.schemas (or similar path): Contains default GDM settings and schemas.
Changes to these files often require a restart of the GDM service (e.g., systemctl restart gdm) for them to take effect.

During the boot process, after the kernel and initial system services have started, the systemd service for GDM (typically gdm.service) is invoked.
This service then launches the gdm-binary executable, which initializes the graphical display, starts the greeter, and waits for user input.
Once a user successfully logs in, gdm-binary takes responsibility for starting their selected desktop environment session.

GDM, and consequently gdm-binary, has served as the default display manager for the GNOME desktop environment since its early versions.
It was developed to replace older display managers like xdm, aiming to offer a more integrated and user-friendly experience for GNOME users.
Over the years, its development has mirrored the evolution of the Linux desktop, adapting from primarily managing X11 sessions to incorporating full support for Wayland, and continually improving its security and session management capabilities.

gdm(8), systemctl(1), Xorg(1), Wayland(7), lightdm(1), sddm(1)