NAME
editline - command-line editing library with history
SYNOPSIS
char *readline(char *prompt)
DESCRIPTION
Editline is a library that provides an line-editing inter-
face with text recall. It is intended to be compatible with
the readline library provided by the Free Software Founda-
tion, but much smaller. The bulk of this manual page
describes the user interface.
The readline routine returns a line of text with the trail-
ing newline removed. The data is returned in a buffer allo-
cated with malloc(3), so the space should be released with
free(3) when the calling program is done with it. Before
accepting input from the user, the specified prompt is
displayed on the terminal.
Each line returned is copied to the internal history list,
unless it happens to be equal to the previous line.
User Interface
A program that uses this library provides a simple emacs-
like editing interface to its users. A line may be edited
before it is sent to the calling program by typing either
control characters or escape sequences. A control charac-
ter, shown as a caret followed by a letter, is typed by
holding down the ``control'' key while the letter is typed.
For example, ``^A'' is a control-A. An escape sequence is
entered by typing the ``escape'' key followed by one or more
characters. The escape key is abbreviated as ``ESC.'' Note
that unlike control keys, case matters in escape sequences;
``ESC F'' is not the same as ``ESC f''.
An editing command may be typed anywhere on the line, not
just at the beginning. In addition, a return may also be
typed anywhere on the line, not just at the end.
Most editing commands may be given a repeat count, n, where
n is a number. To enter a repeat count, type the escape
key, the number, and then the command to execute. For exam-
ple, ``ESC 4 ^f'' moves forward four characters. If a com-
mand may be given a repeat count then the text ``[n]'' is
given at the end of its description.
The following control characters are accepted:
^A Move to the beginning of the line
^B Move left (backwards) [n]
^D Delete character [n]
^E Move to end of line
^F Move right (forwards) [n]
^G Ring the bell
^H Delete character before cursor (backspace key) [n]
^I Complete filename (tab key); see below
^J Done with line (return key)
^K Kill to end of line (or column [n])
^L Redisplay line
^M Done with line (alternate return key)
^N Get next line from history [n]
^P Get previous line from history [n]
^R Search backward (forward if [n]) through history for text;
must start line if text begins with an uparrow
^T Transpose characters
^V Insert next character, even if it is an edit command
^W Wipe to the mark
^X^X Exchange current location and mark
^Y Yank back last killed text
^[ Start an escape sequence (escape key)
^]c Move forward to next character ``c''
^? Delete character before cursor (delete key) [n]
The following escape sequences are provided.
ESC ^H Delete previous word (backspace key) [n]
ESC DEL Delete previous word (delete key) [n]
ESC SP Set the mark (space key); see ^X^X and ^Y above
ESC . Get the last (or [n]'th) word from previous line
ESC ? Show possible completions; see below
ESC < Move to start of history
ESC > Move to end of history
ESC b Move backward a word [n]
ESC d Delete word under cursor [n]
ESC f Move forward a word [n]
ESC l Make word lowercase [n]
ESC m Toggle if 8bit chars display normally or with ``M-'' prefix
ESC u Make word uppercase [n]
ESC y Yank back last killed text
ESC v Show library version
ESC w Make area up to mark yankable
ESC nn Set repeat count to the number nn
ESC C Read from environment variable ``_C_'', where C is
an uppercase letter
The editline library has a small macro facility. If you
type the escape key followed by an uppercase letter, C, then
the contents of the environment variable _C_ are read in as
if you had typed them at the keyboard. For example, if the
variable _L_ contains the following:
^A^Kecho '^V^[[H^V^[[2J'^M
Then typing ``ESC L'' will move to the beginning of the
line, kill the entire line, enter the echo command needed to
clear the terminal (if your terminal is like a VT-100), and
send the line back to the shell.
The editline library also does filename completion. Suppose
the root directory has the following files in it:
bin vmunix
core vmunix.old
If you type ``rm /v'' and then the tab key. Editline will
then finish off as much of the name as possible by adding
``munix''. Because the name is not unique, it will then
beep. If you type the escape key and a question mark, it
will display the two choices. If you then type a period and
a tab, the library will finish off the filename for you:
rm /v[TAB]munix.TABold
The tab key is shown by ``[TAB]'' and the automatically-
entered text is shown in italics.
BUGS AND LIMITATIONS
Doesn't know how to handle multiple lines.
AUTHORS
Simmule R. Turner <uunet.uu.net!capitol!sysgo!simmy> and
Rich $alz <rsalz@osf.org>. Original manual page by DaviD W.
Sanderson <dws@ssec.wisc.edu>.