gdb.info: Readline Bare Essentials

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Readline Bare Essentials

In order to enter characters into the line, simply type them.  The typed
character appears where the cursor was, and then the cursor moves one
space to the right.  If you mistype a character, you can use your erase
character to back up and delete the mistyped character.
   Sometimes you may mistype a character, and not notice the error
until you have typed several other characters.  In that case, you can
type `C-b' to move the cursor to the left, and then correct your
mistake.  Afterwards, you can move the cursor to the right with `C-f'.
   When you add text in the middle of a line, you will notice that
characters to the right of the cursor are `pushed over' to make room
for the text that you have inserted.  Likewise, when you delete text
behind the cursor, characters to the right of the cursor are `pulled
back' to fill in the blank space created by the removal of the text.  A
list of the bare essentials for editing the text of an input line
follows.
`C-b'
     Move back one character.
`C-f'
     Move forward one character.
<DEL> or <Backspace>
     Delete the character to the left of the cursor.
`C-d'
     Delete the character underneath the cursor.
Printing characters
     Insert the character into the line at the cursor.
`C-_' or `C-x C-u'
     Undo the last editing command.  You can undo all the way back to an
     empty line.
(Depending on your configuration, the <Backspace> key be set to delete
the character to the left of the cursor and the <DEL> key set to delete
the character underneath the cursor, like `C-d', rather than the
character to the left of the cursor.)