edit(1)edit(1)NAMEedit - Edits a file line by line with a simplified command set
SYNOPSISedit [-c subcommand] [-lRv] [-wnumber] [+subcommand] [-] [file...]
edit [-c subcommand] [-lRv] [-t tag] [file...]
edit [-c subcommand] -r[file] [-lRv] [file]
The edit command provides a line editor designed for beginning users.
OPTIONS
Indents appropriately for LISP code, and accepts the (, ), {, }, [, and
] characters (parentheses, braces, and brackets) as text rather than
interpreting them as vi subcommands. The LISP modifier is active in
open or visual modes. Recovers file after an editor or system crash.
If you do not specify file, a list of all saved files is displayed.
Sets the readonly option, preventing you from altering the file. Loads
the file that contains tag and positions the editor at tag. To use
this option, you must first create a database of function names and
locations using the ctags command. Invokes the visual editor. When the
-v option is specified, an enlarged set of subcommands are available,
including screen editing and cursor movement features. See vi. Sets
the default window size to number lines. Suppresses all interactive
user feedback. If you use this option, file input/output errors do not
generate an error message. Begins the edit with the specified editor
search or subcommand. When subcommand is not entered, a + (plus sign)
sets the current line to the bottom of the file. Normally edit sets
the current line to the last line of the file, or to some specified tag
or pattern.
DESCRIPTION
The edit command is part of a family of editors that also includes ed,
ex, and vi. It is a simplified version of the ex editor, which itself
is built on the ed line editor.
To edit the contents of a file, enter: edit file
If file is the name of an existing file, edit copies it to a buffer and
displays the number of lines and characters in it. Then it displays a
: (colon) prompt to show that it is ready to read subcommands from
standard input.
If file does not already exist, edit tells you this. You can give more
than one file, in which case edit copies the first file into its buffer
and stores the remaining filenames in an argument list for later use.
The edit command does not make changes to the file until you use the w
subcommand to write the changes.
Editing Modes
The edit command operates in one of two modes: In command mode, the
edit editor recognizes and executes subcommands. When you start the
editor, it is in command mode. In text input mode, you can add text to
the editing buffer. You enter text input mode by using the a, c, or i
subcommand. To exit text input mode (and return to command mode), you
enter a (dot) alone at the beginning of a line.
Subcommand Syntax
The general format of an edit subcommand is as follows: [address]sub‐
command[argument ...][count]
If you do not specify an address, edit works on the current line. When
you start the edit program, the current line is the last line in the
buffer. As you edit the buffer, the current line changes to the last
line affected by a subcommand. (When edit reads a file into its buffer,
the last line affected by the process of reading is the last line in
the file.) If you add a numeric count to most subcommands, edit works
on the specified number of lines.
The value for address can be a line number or a pattern to be matched
or, in some cases, a range of line numbers or patterns. To specify a
range, separate two line numbers or patterns with a comma or a semi‐
colon (for example, 1,5 or 1;5). In a range, the second address must
refer to a line that follows the first addressed line in the range.
To work with different parts of a file, you must know how to find out
the current line and how to address different lines in a file.
Addressing Lines Within a File
The simplest way to address a line within a file is to use its line
number. But this can be unreliable because line numbers change when
you insert and delete lines. The edit command provides a way to search
through the buffer for strings. Given the following address, edit
searches forward for pattern: /pattern/
If given the following address, edit searches backward for pattern:
?pattern?
If a forward search reaches the end of the buffer without finding pat‐
tern, it continues the search at the beginning of the file until it
reaches the current line. A backward search does just the reverse.
The following characters have special meanings in these search pat‐
terns: Matches the beginning of a line. Matches the end of a line.
Thus, you can use /^pattern/ to search for patterns at the beginning of
a line, and /pattern$/ to search for patterns at the end of the line.
Lines can be addressed by their line numbers; for example, 11 refers to
line 11 of the buffer. In addition, the current line is addressed with
a (dot) and the last line in the buffer is addressed with a $ (dollar
sign). This is useful when working with a range of lines. For exam‐
ple, the following command displays all lines from the current line to
the last line in the buffer: .,$print
Do not confuse the meaning of $ in text patterns, end of line, with its
meaning in addresses, last line. Arithmetic with line references is
also possible, so that $-5 refers to the fifth line from the last and
refers to the line 20 lines past the current line. You can also use
the = (equal sign) command to find out the line number of the current
line or the last line, as follows: .= $=
To view the next line in the buffer, press <Return>. Press <Ctrl-d> to
display the next half-screen of lines.
Using a Family of Editors
As you become more experienced with edit, you might want to try the
advanced features of one of the other editors in the family. Because
edit is part of a family of editors, you can apply your knowledge of
edit to the other editors in the family.
The ex editor is a powerful interactive line editor. The edit subcom‐
mands work the same way in ex, but the editing environment is somewhat
different. For example in edit, only the characters ^ (circumflex), $
(dollar sign), and \ (backslash) have special meanings as pattern-
matching characters; however, several additional characters also have
special meanings in ex.
SUBCOMMANDS
Unless otherwise noted, all subcommands work by default on the current
line; address is optional. You can use the full subcommand or its
abbreviation. Subcommand abbreviations appear after the command in the
sections that follow.
You can use the 1,$p subcommand to display the entire contents of the
buffer.
The edit program recognizes and interprets the following subcommands
when it displays the colon prompt.
Adding Text
Appends the text you type after the current line, if you do not specify
an address. If you specify an address, the a subcommand appends text
after the addressed line. If you specify address 0 (zero), the a sub‐
command places the text at the beginning of the buffer. As you type
your text, press <Return> at the end of each line. When you have
entered all your text, enter a (dot) alone at the start of a line.
This ends text input mode and returns to command mode. Places the
given text before the specified line. Enter a (dot) to return to com‐
mand mode. The last line input becomes the current line.
Changing Text
Replaces the current line or addressed line or lines with the input
text. Enter a (dot) to return to command mode. If any lines are input,
the last input line becomes the new current line.
Deleting Text
Removes the specified line or lines from the editing buffer. The line
following the last deleted line becomes the current line. If you spec‐
ify a buffer by giving a letter from a to z, edit saves the specified
lines in that buffer or, if the letter is uppercase, appends the lines
to that buffer.
Displaying Text and Determining the Current Line
Displays the current filename along with the following information:
Whether it was modified since the last write. What the current line
is. How many lines are in the buffer. What percentage of the way
through the buffer the current line is.
Also, sets the current filename if file is specified. Displays
each specified line or lines preceded by its buffer line number.
The last line displayed becomes the current line. Displays the
specified line or lines. The last line displayed becomes the
current line. Displays the line number of the addressed line.
If you do not specify an address, displays the line number of
the last line. Displays a screen of text, beginning with the
current or specified line. Displays a screen of text, with the
specified (or current) line at the bottom of the screen. Dis‐
plays a screen of text, with the specified (or current) line in
the middle of the screen.
Editing Another File
Begins an editing session on a new file. The editor first checks to
see if the buffer was modified since the last write subcommand. If it
has, edit issues a warning and cancels the edit subcommand. Otherwise,
it deletes the complete contents of the editor buffer, makes the named
file the current file, and displays the new filename. After ensuring
that this file can be edited, it reads the file into its buffer. If
edit reads the file without error, it displays the number of lines and
characters that it read. The last line read becomes the new current
line. Copies the next file in the command line argument list to the
buffer for editing.
You can edit a sequence or group of files. You can use the next
subcommand to edit each file on the command line in turn, or to
specify a list of filenames to edit (using the shell pattern
matching syntax) instead. The wildcard character % represents
the name of the current edit file and can be used to form file‐
names. If file is specified, the command line argument list is
replaced, and an edit command is performed on the first file.
Making Global Changes
Marks each of the specified lines that matches the pattern, then car‐
ries out the specified subcommands (commands) on each marked line.
A single command or the first command in a subcommand list
appears on the same line as global. The remaining commands must
appear on separate lines, where each line (except the last) ends
with a \ (backslash). The default subcommand is print.
The subcommand list can include the append, insert, and change
subcommands and their associated input. In this case, if the
ending period comes on the last line of the command list, you
can omit it. The undo subcommand and the global subcommand
itself, however, cannot appear in the command list. See also
Substituting Text.
Moving or Copying Text
Repositions the specified line or lines to follow address3. The first
of the moved lines becomes the current line. address1 and address2 are
optional; you must specify address3. Places the specified line or
lines in buffer (identified by a single alpha character name a to z).
Retrieves the contents of the specified buffer and places it after
address. If you do not specify a buffer, edit restores the last
deleted or yanked text. Thus, you can use this subcommand together
with delete to move lines or with yank to duplicate lines between
files.
Quitting an Editing Session
Ends the editing session. The quit command does not write the editor
buffer to a file; if you have modified the contents of the buffer since
the last write, edit displays a warning message and does not end the
session. In this case, either use the quit! subcommand to discard the
buffer or write the buffer and then quit.
Saving Text
Writes the contents of the specified line or lines to file. The
default range is all lines in the buffer. edit displays the number of
lines and characters that it writes. If you do not specify a file,
edit uses the current filename. If file does not exist, edit creates
it. Saves the current editor buffer as though the system had just
crashed. Use this command when a write subcommand has resulted in an
error, and you do not know how to save your work. Recovers file from
the system save area. Use this after a system crash, or a preserve sub‐
command.
Substituting Text
Replaces on each specified line the first instance of pattern with the
replacement pattern replacement. If you add the global indicator g, it
replaces all instances of pattern on each specified line.
Undoing a Change
Reverses the changes made in the buffer by the last buffer editing sub‐
command. Note that global subcommands are considered a single subcom‐
mand to an undo. You cannot undo a write or an edit subcommand.
SEE ALSO
Commands: ed(1), ex(1), vi(1)edit(1)
