There are a range of editor commands which operate only on the Echo Area (that is, the buffer where the user types in commands).
Although in many cases the key bindings have a similar effect to the bindings used in ordinary buffers, this is just for the convenience of the user. In fact the commands that are invoked are different.
Many of the commands used in the Editor are long, in the knowledge that the user can use completion commands in the Echo Area, and so rarely has to type a whole command name. Details of these completion commands are given below.
Arguments: None
Key sequence: Tab
Mode: Echo Area
Completes the text in the Echo Area as far as possible, thereby saving the user from having to type in the whole of a long file name or command. Use Tab Tab to produce a popup list of all possible completions.
Arguments: None
Key sequence: Space
Mode: Echo Area
Completes the current part of the text in the Echo Area. So, for a command that involves two or more words, if Complete Field is used when part of the first word has been entered, an attempt is made to complete just that word.
Arguments: None
Key sequence: Return
Mode: Echo Area
Terminates an entry in the Echo Area. The Editor then tries to parse the entry. If Return is typed in the Echo Area when nothing is being parsed, or the entry is erroneous, an error is signaled.
Arguments: None
Key sequence: ? or Help or F1
Mode: Echo Area
Displays a popup list of all possible completions of the text in the echo area.
The Echo Area commands are recorded in a history ring so that they can be easily repeated. Details of these commands are given below.
Arguments: None
Key sequence: Meta+P
Mode: Echo Area
Moves to the previous command in the Echo Area history ring. If the current input is not empty and the contents are different from what is on the top of the ring, then this input is pushed onto the top of the ring before the new input is inserted.
Arguments: None
Key sequence: Meta+N
Mode: Echo Area
Moves to the next most recent command in the Echo Area history ring. If the current input is not empty and the contents are different from what is on the top of the ring, then this input is pushed onto the top of the ring before the new input is inserted.
Find Matching Parse Editor Command
Arguments: match-input-string
Key sequence: Meta+R
Mode: Echo Area
The command Find Matching Parse searches for a previous input containing match-input-string, and replaces the current input with it.
Echo Area Backward Character Editor Command
Arguments: None
Key sequence: Ctrl+B
Mode: Echo Area
Moves the cursor back one position (without moving into the prompt).
Echo Area Backward Word Editor Command
Arguments: None
Key sequence: Meta+B
Mode: Echo Area
Moves the cursor back one word (without moving into the prompt).
Beginning of Parse Editor Command
Arguments: None
Key sequence: Meta+<
Mode: Echo Area
Moves the cursor to the location immediately after the prompt in the Echo Area.
Beginning of Parse or Line Editor Command
Arguments: None
Key sequence: Ctrl+A
Mode: Echo Area
Moves the cursor to the location at the start of the current line in multi-line input, or to the location immediately after the prompt in the Echo Area.
Echo Area Delete Previous Character Editor Command
Arguments: None
Key sequence: Backspace
Mode: Echo Area
Deletes the previous character entered in the Echo Area.
Echo Area Kill Previous Word Editor Command
Arguments: None
Key sequence: Meta+Backspace
Mode: Echo Area
Kills the previous word entered in the Echo Area.
Arguments: None
Key sequence: Ctrl+C Ctrl+U
Mode: Echo Area
Kills the whole of the input so far entered in the Echo Area.
Insert Parse Default Editor Command
Arguments: None
Key sequence: Ctrl+C Ctrl+P
Mode: Echo Area
Inserts the default value for the parse in progress at the location of the cursor. It is thereby possible to edit the default. Simply typing Return selects the default without any editing.
Arguments: None
Key sequence: Ctrl+C Ctrl+R
Mode: Echo Area
Uses the default value for the parse in progress. This is the same as issuing the command Insert Parse Default and then pressing Return immediately.
Insert Selected Text Editor Command
Arguments: None
Key sequence: Ctrl+C Ctrl+C
Mode: Echo Area
Inserts the editor window's selected text in the echo area.
What Cursor Position Editor Command
Arguments: None
Key sequence: Ctrl+X =
Mode: Echo Area
Displays in the echo area the character under the point and the column of the point.
See also: Toggle Showing Cursor Info.
Arguments: None
Key sequence: None
Displays in the echo area the position of the current point in terms of characters in the buffer, as a fraction of current point position over total buffer length.
Toggle Showing Cursor Info Editor Command
Arguments: None
Key sequence: None
The command Toggle Showing Cursor Info switches on or off display of cursor info in the echo area.
When display of cursor info is on, the info is updated whenever the cursor moves.
The info contains the character at the cursor position, its Unicode code point, position in the buffer, and column. It is the same information that is given by What Cursor Position.
Reset Echo Area Editor Command
Arguments: None
Key sequence: Meta+K
Mode: Echo Area
The command Reset Echo Area resets the echo area, which means aborting any prompting ("recursive edit") and moving the focus to the main editor pane.
Editor User Guide (Unix version) - 01 Dec 2021 19:35:18