Editing Terminal emulator (section)

===Line-at-a-time mode/Local editing===
{{main|Computer terminal#Modes}}

Terminal emulators may implement local editing, also known as "line-at-a-time mode". This is also mistakenly referred to as "[[half-duplex]]".{{citation needed|date=December 2017}} In this mode, the terminal emulator only sends complete lines of input to the host system. The user enters and edits a line, but it is held locally within the terminal emulator as it is being edited. It is not transmitted until the user signals its completion, usually with the {{keypress|Enter}} key on the keyboard or a "send" button of some sort in the user interface. At that point, the entire line is transmitted. Line-at-a-time mode implies local echo, since otherwise the user will not be able to see the line as it is being edited and constructed.{{sfn|Daintith|2004|p=171}}{{sfn|Bangia|2010|p=324}} However, line-at-a-time mode is independent of echo mode and does not ''require'' local echo. When entering a password, for example, line-at-a-time entry with local editing is possible, but local echo is turned off (otherwise the password would be displayed).{{sfn|Stevens|Wright|1994|p=413}}

The complexities of line-at-a-time mode are exemplified by the line-at-a-time mode option in the telnet protocol. To implement it correctly, the ''Network Virtual Terminal'' implementation provided by the terminal emulator program must be capable of recognizing and properly dealing with "interrupt" and "abort" events that arrive in the middle of locally editing a line.{{sfn|Miller|2009|p=590, 591}}