ED(1) ED(1)
NAME
ed - text editor
SYNOPSIS
ed [ - ] [ -o ] [ file ]
DESCRIPTION
Ed is a venerable text editor.
If a file argument is given, ed simulates an `e' command
(see below) on that file: it is read into ed's buffer so
that it can be edited. The options are
- Suppress the printing of character counts by `e', `r',
and `w' commands and of the confirming `!' by `!'
commands.
-o (for output piping) Write all output to the standard
error file except writing by `w' commands. If no file
is given, make /fd/1 the remembered file; see the `e'
command below.
Ed operates on a `buffer', a copy of the file it is editing;
changes made in the buffer have no effect on the file until
a `w' (write) command is given. The copy of the text being
edited resides in a temporary file called the buffer.
Commands to ed have a simple and regular structure: zero,
one, or two addresses followed by a single character
command, possibly followed by parameters to the command.
These addresses specify one or more lines in the buffer.
Missing addresses are supplied by default.
In general, only one command may appear on a line. Certain
commands allow the addition of text to the buffer. While ed
is accepting text, it is said to be in input mode. In this
mode, no commands are recognized; all input is merely col-
lected. Input mode is left by typing a period `.' alone at
the beginning of a line.
Ed supports the regular expression notation described in
regexp(6). Regular expressions are used in addresses to
specify lines and in one command (see s below) to specify a
portion of a line which is to be replaced. If it is desired
to use one of the regular expression metacharacters as an
ordinary character, that character may be preceded by `\'.
This also applies to the character bounding the regular
expression (often `/') and to `\' itself.
To understand addressing in ed it is necessary to know that
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at any time there is a current line. Generally, the current
line is the last line affected by a command; however, the
exact effect on the current line is discussed under the
description of each command. Addresses are constructed as
follows.
1. The character `.', customarily called `dot', addresses
the current line.
2. The character `$' addresses the last line of the
buffer.
3. A decimal number n addresses the n-th line of the
buffer.
4. 'x addresses the line marked with the name x, which
must be a lower-case letter. Lines are marked with the
`k' command.
5. A regular expression enclosed in slashes ( `/')
addresses the line found by searching forward from the
current line and stopping at the first line containing
a string that matches the regular expression. If nec-
essary the search wraps around to the beginning of the
buffer.
6. A regular expression enclosed in queries `?' addresses
the line found by searching backward from the current
line and stopping at the first line containing a string
that matches the regular expression. If necessary the
search wraps around to the end of the buffer.
7. An address followed by a plus sign `+' or a minus sign
`-' followed by a decimal number specifies that address
plus (resp. minus) the indicated number of lines. The
plus sign may be omitted.
8. An address followed by `+' (or `-') followed by a regu-
lar expression enclosed in slashes specifies the first
matching line following (or preceding) that address.
The search wraps around if necessary. The `+' may be
omitted, so `0/x/' addresses the first line in the
buffer with an `x'. Enclosing the regular expression
in `?' reverses the search direction.
9. If an address begins with `+' or `-' the addition or
subtraction is taken with respect to the current line;
e.g. `-5' is understood to mean `.-5'.
10. If an address ends with `+' or `-', then 1 is added
(resp. subtracted). As a consequence of this rule and
rule 9, the address `-' refers to the line before the
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current line. Moreover, trailing `+' and `-' charac-
ters have cumulative effect, so `--' refers to the cur-
rent line less 2.
11. To maintain compatibility with earlier versions of the
editor, the character `^' in addresses is equivalent to
`-'.
Commands may require zero, one, or two addresses. Commands
which require no addresses regard the presence of an address
as an error. Commands which accept one or two addresses
assume default addresses when insufficient are given. If
more addresses are given than a command requires, the last
one or two (depending on what is accepted) are used.
Addresses are separated from each other typically by a comma
`,'. They may also be separated by a semicolon `;'. In
this case the current line is set to the previous address
before the next address is interpreted. If no address pre-
cedes a comma or semicolon, line 1 is assumed; if no address
follows, the last line of the buffer is assumed. The second
address of any two-address sequence must correspond to a
line following the line corresponding to the first address.
In the following list of ed commands, the default addresses
are shown in parentheses. The parentheses are not part of
the address, but are used to show that the given addresses
are the default. `Dot' means the current line.
(.)a
<text>
. Read the given text and append it after the addressed
line. Dot is left on the last line input, if there
were any, otherwise at the addressed line. Address `0'
is legal for this command; text is placed at the begin-
ning of the buffer.
(.,.)b[+-][pagesize][pln]
Browse. Print a `page', normally 20 lines. The
optional `+' (default) or `-' specifies whether the
next or previous page is to be printed. The optional
pagesize is the number of lines in a page. The
optional `p', `n', or `l' causes printing in the speci-
fied format, initially `p'. Pagesize and format are
remembered between `b' commands. Dot is left at the
last line displayed.
(.,.)c
<text>
. Change. Delete the addressed lines, then accept input
text to replace these lines. Dot is left at the last
line input; if there were none, it is left at the line
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preceding the deleted lines.
(.,.)d
Delete the addressed lines from the buffer. Dot is set
to the line following the last line deleted, or to the
last line of the buffer if the deleted lines had no
successor.
e filename
Edit. Delete the entire contents of the buffer; then
read the named file into the buffer. Dot is set to the
last line of the buffer. The number of characters read
is typed. The file name is remembered for possible use
in later `e', `r', or `w' commands. If filename is
missing, the remembered name is used.
E filename
Unconditional `e'; see ``q'' below.
f filename
Print the currently remembered file name. If filename
is given, the currently remembered file name is first
changed to filename.
(1,$)g/regular expression/command list
(1,$)g/regular expression/
(1,$)g/regular expression
Global. First mark every line which matches the given
regular expression. Then for every such line, execute
the command list with dot initially set to that line.
A single command or the first of multiple commands
appears on the same line with the global command. All
lines of a multi-line list except the last line must
end with `\'. The `.' terminating input mode for an
`a', `i', `c' command may be omitted if it would be on
the last line of the command list. The commands `g'
and `v' are not permitted in the command list. Any
character other than space or newline may be used
instead of `/' to delimit the regular expression. The
second and third forms mean g/regular expression/p.
(.)i
<text>
. Insert the given text before the addressed line. Dot
is left at the last line input, or, if there were none,
at the line before the addressed line. This command
differs from the a command only in the placement of the
text.
(.,.+1)j
Join the addressed lines into a single line; intermedi-
ate newlines are deleted. Dot is left at the resulting
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line.
(.)kx
Mark the addressed line with name x, which must be a
lower-case letter. The address form 'x then addresses
this line.
(.,.)l
List. Print the addressed lines in an unambiguous way:
a tab is printed as `\t', a backspace as `\b', back-
slashes as `\\', and non-printing characters as a back-
slash, an `x', and four hexadecimal digits. Long lines
are folded, with the second and subsequent sub-lines
indented one tab stop. If the last character in the
line is a blank, it is followed by `\n'. An `l' may be
appended, like `p', to any non-I/O command.
(.,.)ma
Move. Reposition the addressed lines after the line
addressed by a. Dot is left at the last moved line.
(.,.)n
Number. Perform `p', prefixing each line with its line
number and a tab. An `n' may be appended, like `p', to
any non-I/O command.
(.,.)p
Print the addressed lines. Dot is left at the last
line printed. A `p' appended to any non-I/O command
causes the then current line to be printed after the
command is executed.
(.,.)P
This command is a synonym for `p'.
q Quit the editor. No automatic write of a file is done.
A `q' or `e' command is considered to be in error if
the buffer has been modified since the last `w', `q',
or `e' command.
Q Quit unconditionally.
($)r filename
Read in the given file after the addressed line. If no
filename is given, the remembered file name is used.
The file name is remembered if there were no remembered
file name already. If the read is successful, the num-
ber of characters read is printed. Dot is left at the
last line read from the file.
(.,.)sn/regular expression/replacement/
(.,.)sn/regular expression/replacement/g
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(.,.)sn/regular expression/replacement
Substitute. Search each addressed line for an occur-
rence of the specified regular expression. On each
line in which n matches are found (n defaults to 1 if
missing), the nth matched string is replaced by the
replacement specified. If the global replacement indi-
cator `g' appears after the command, all subsequent
matches on the line are also replaced. It is an error
for the substitution to fail on all addressed lines.
Any character other than space or newline may be used
instead of `/' to delimit the regular expression and
the replacement. Dot is left at the last line substi-
tuted. The third form means
sn/regular expression/replacement/p. The second `/'
may be omitted if the replacement is empty.
An ampersand `&' appearing in the replacement is
replaced by the string matching the regular expression.
The characters \n, where n is a digit, are replaced by
the text matched by the n-th regular subexpression
enclosed between `(' and `)'. When nested parenthe-
sized subexpressions are present, n is determined by
counting occurrences of `(' starting from the left.
A literal `&', `/', `\' or newline may be included in a
replacement by prefixing it with `\'.
(.,.)ta
Transfer. Copy the addressed lines after the line
addressed by a. Dot is left at the last line of the
copy.
(.,.)u
Undo. Restore the preceding contents of the first
addressed line (sic), which must be the last line in
which a substitution was made (double sic).
(1,$)v/regular expression/command list
This command is the same as the global command `g'
except that the command list is executed with dot ini-
tially set to every line except those matching the reg-
ular expression.
(1,$)w filename
Write the addressed lines to the given file. If the
file does not exist, it is created with mode 666 (read-
able and writable by everyone). If no filename is
given, the remembered file name, if any, is used. The
file name is remembered if there were no remembered
file name already. Dot is unchanged. If the write is
successful, the number of characters written is
printed.
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(1,$)W filename
Perform `w', but append to, instead of overwriting, any
existing file contents.
($)= Print the line number of the addressed line. Dot is
unchanged.
!shell command
Send the remainder of the line after the `!' to rc(1)
to be interpreted as a command. Dot is unchanged.
(.+1)<newline>
An address without a command is taken as a `p' command.
A terminal `/' may be omitted from the address. A
blank line alone is equivalent to `.+1p'; it is useful
for stepping through text.
If an interrupt signal (DEL) is sent, ed prints a `?' and
returns to its command level.
When reading a file, ed discards NUL characters and all
characters after the last newline.
FILES
/tmp/e*
ed.hup work is saved here if terminal hangs up
SOURCE
/sys/src/cmd/ed.c
SEE ALSO
sam(1), sed(1), regexp(6)
DIAGNOSTICS
?name for inaccessible file; `?TMP' for temporary file over-
flow; `?' for errors in commands or other overflows.
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