reset

Reinitialize the current terminal

$ reset

$ reset -q

reset [-IQKP]

-I
    Re-initializes the terminal. This is equivalent to invoking 'tput init', which sends the terminal's initialization strings from the terminfo database.

-Q
    Causes 'reset' to output both the 'init' string (initialization) and the 'reset' string from the terminfo database. Useful for a more comprehensive reset.

-K
    Resets the terminal's keypad. This sends the 'keypad_normal' (kcrmn) string from the terminfo database, restoring the keypad to its normal (non-application) mode.

-P
    Resets the terminal's programmable function keys. This sends the 'keypad_xmit' (kf) string, which often sets function keys to their default behaviors.

The `reset` command is a utility designed to restore a terminal's state to a known, default configuration. It is invaluable when a terminal session becomes garbled, unresponsive, or exhibits strange behavior due to misconfigured programs, incorrect control sequences, or the accidental display of binary files.

Essentially, `reset` sends a series of initialization and reset sequences from the `terminfo` database, specific to the terminal type defined by the `TERM` environment variable. These sequences typically clear the screen, reset tab stops, disable special character mappings (like raw mode), re-enable echoing of characters, and restore standard cursor and display attributes.

While often appearing as a standalone command, `reset` is commonly a hard link to or an alias for `tput reset` or `tput init`, leveraging the capabilities of the `ncurses` library to interact with the terminal's control sequences. It's a quick fix to get your terminal back to a usable state without needing to close and reopen the session.

• `reset` relies on the correct `TERM` environment variable being set. If `TERM` is incorrect, `reset` might send inappropriate sequences, potentially worsening the terminal state or having no effect.
• While `reset` aims to restore a sane state, some extremely malformed terminal states might not be fully recoverable without closing and reopening the terminal session.
• It typically clears the entire screen, which can wipe out previous command output or scrollback history in some terminal emulators.

The `reset` command is most frequently used in situations where your terminal display becomes unreadable or unresponsive. This often happens after:
• Accidentally displaying a binary file: Using `cat` on an executable or image file can print non-printable characters that alter terminal settings.
• A program crashes or exits improperly: Some applications may leave the terminal in a raw input mode, or change character sets, making further interaction difficult.
• Incorrect terminal settings applied: Sometimes, a script or misconfiguration can apply incorrect escape sequences.

The effectiveness of `reset` heavily depends on the `TERM` environment variable. This variable tells the system what type of terminal you are using (e.g., `xterm`, `linux`, `vt100`). `reset` (via `tput`) consults the `terminfo` database for the initialization and reset sequences specific to the `TERM` type. If `TERM` is unset or set incorrectly, `reset` may fail to properly restore the terminal.

The `reset` command is an integral part of the `ncurses` (new curses) library, which provides a powerful and portable way to write text-based user interfaces. Its origins are tied to the need for robust terminal control in Unix-like systems. Historically, `reset` often existed as a standalone executable, frequently implemented as a hard link to `tput`. This approach allows `reset` to leverage `tput`'s ability to query and apply terminal capabilities defined in the `terminfo` database, ensuring compatibility across a vast array of terminal types and emulators. Its continued relevance highlights the persistent challenge of managing diverse terminal control sequences in modern computing environments.

tput(1), stty(1), clear(1), setterm(1), terminfo(5)