ED(1) | General Commands Manual | ED(1) |
ed
—
ed |
[- ] [-ESsx ]
[-p string]
[file] |
ed
is a line-oriented text editor. It is used to create,
display, modify, and otherwise manipulate text files. If invoked with a
file argument, then a copy of file
is read into the editor's buffer. Changes are made to this copy and not
directly to file itself. Upon quitting
ed
, any changes not explicitly saved with a
w
command are lost.
Editing is done in two distinct modes: command
and input. When first invoked, ed
is in command mode. In this mode, commands are read from the standard input
and executed to manipulate the contents of the editor buffer.
A typical command might look like:
,s/old/new/g
which replaces all occurrences of the string old with new.
When an input command, such as a
(append),
i
(insert), or c
(change) is
given, ed
enters input mode. This is the primary
means of adding text to a file. In this mode, no commands are available;
instead, the standard input is written directly to the editor buffer. Lines
consist of text up to and including a newline character. Input mode is
terminated by entering a single period
(‘.
’) on a line.
All ed
commands operate on whole lines or
ranges of lines; e.g., the d
command deletes lines;
the m
command moves lines, and so on. It is possible
to modify only a portion of a line by means of replacement, as in the
example above. However, even here, the s
command is
applied to whole lines at a time.
In general, ed
commands consist of zero or
more line addresses, followed by a single character command and possibly
additional parameters; i.e., commands have the structure:
[address [,address]]command[parameters]
The address(es) indicate the line or range of lines to be affected by the command. If fewer addresses are given than the command accepts, then default addresses are supplied.
The options are as follows:
-
-s
option (deprecated).-E
-p
stringP
command.-S
!
command (executing a
subshell). Intended to be used by batch jobs like
patch(1).-s
ed
standard input is from a script.-x
x
command).!
’), then it
is interpreted as a shell command. In this case, what is read is the
standard output of file executed via
sh(1). To read a file whose name
begins with a bang, prefix the name with a backslash
(‘\
’). The default filename is set
to file only if it is not prefixed with a bang.ed
maintains a current address which
is typically supplied to commands as the default address when none is
specified. When a file is first read, the current address is set to the last
line of the file. In general, the current address is set to the last line
affected by a command.
A line address is constructed from one of the bases in the list below, optionally followed by a numeric offset. The offset may include any combination of digits, operators (i.e., ‘+’, ‘-’, and ‘^’), and whitespace. Addresses are read from left to right, and their values are computed relative to the current address.
One exception to the rule that addresses represent line numbers is the address 0 (zero). This means “before the first line”, and is legal wherever it makes sense.
An address range is two addresses separated either by a comma or semi-colon. The value of the first address in a range cannot exceed the value of the second. If only one address is given in a range, then the second address is set to the given address. If an n-tuple of addresses is given where n > 2, then the corresponding range is determined by the last two addresses in the n-tuple. If only one address is expected, then the last address is used.
Each address in a comma-delimited range is interpreted relative to the current address. In a semi-colon-delimited range, the first address is used to set the current address, and the second address is interpreted relative to the first.
The following address symbols are recognized:
k
(mark) command,
where lc is a lower case letter.ed
command
g/string/
prints all lines containing string. Regular
expressions are also used by the s
command for
selecting old text to be replaced with new.
In addition to specifying string literals, regular expressions can represent classes of strings. Strings thus represented are said to be matched by the corresponding regular expression. If it is possible for a regular expression to match several strings in a line, then the leftmost longest match is the one selected.
The following symbols are used in constructing regular expressions:
Additional regular expression operators may be defined depending on the particular regex(3) implementation.
To include a ‘]’ in a character class, it must be the first character. A range of characters may be specified by separating the end characters of the range with a ‘-’, e.g., ‘a-z’ specifies the lower case characters.
The following literals can also be used within character classes as shorthand for particular sets of characters:
Patterns in a character class of the form [.col-elm.] or [=col-elm=] where col-elm is a collating element are interpreted according to the locale (not currently supported). See regex(3) for an explanation of these constructs.
ed
commands are single characters, though some
require additional parameters. If a command's parameters extend over several
lines, then each line except for the last must be terminated with a backslash
(‘\
’).
In general, at most one command is allowed per line. However, most
commands accept a print suffix, which is any of p
(print), l
(list), or n
(enumerate), to print the last line affected by the command.
An interrupt (typically ^C) has the effect of aborting the current command and returning the editor to command mode.
ed
recognizes the following commands. The
commands are shown together with the default address or address range
supplied if none is specified (in parentheses), and other possible arguments
on the right.
a
c
d
e
filee
!command!
command below). The
default filename is unchanged. Any lines in the buffer are deleted before
the output of command is read. The current address is
set to the last line read.E
filee
command, except that unwritten changes are
discarded without warning. The current address is set to the last line
read.f
fileg
/re/command-listg
command, the current address is set to the last
line affected by command-list.
Each command in command-list must be on
a separate line, and every line except for the last must be terminated
by a backslash (‘\’). Any commands are allowed, except for
g
, G
,
v
, and V
. A newline
alone in command-list is equivalent to a
p
command.
G
/re/G
command, the current address is set to the last
line affected by (the last) command-list.
The format of command-list is the same
as that of the g
command. A newline alone acts
as a null command list. A single ‘&’ repeats the last
non-null command list.
H
ed
scripts
begin with this command to aid in debugging.h
i
j
k
lcl
ed
waits until the RETURN key is pressed before
displaying the next screen. The current address is set to the last line
printed.m
(.)n
p
P
-p
string, the command prompt is by default turned
off.q
ed
.Q
ed
unconditionally. This is similar to the
q
command, except that unwritten changes are
discarded without warning.r
filer
!command!
command
below). The default filename is unchanged. The current address is set to
the last line read.s
/re/replacement/, (.,.)s
/re/replacement/g, (.,.)s
/re/replacement/nre and replacement
may be delimited by any character other than space and newline (see the
s
command below). If one or two of the last
delimiters is omitted, then the last line affected is printed as though
the print suffix p were specified.
An unescaped ‘&
’ in
replacement is replaced by the currently matched
text. The character sequence \m, where
m is a number in the range [1,9], is replaced by the
mth backreference expression
of the matched text. If replacement consists of a
single ‘%
’, then
replacement from the last substitution is used.
Newlines may be embedded in replacement if they
are escaped with a backslash
(‘\
’).
s
s
command accepts a count suffix n, or any combination of
the characters r, g, and
p. If a count suffix n is given, then
only the nth match is replaced.
The r suffix causes the regular expression of the last
search to be used instead of that of the last substitution. The
g suffix toggles the global suffix of the last
substitution. The p suffix toggles the print suffix of
the last substitution. The current address is set to the last line
affected.t
(.)u
g
,
G
, v
, and
V
are treated as a single command by undo.
u
is its own inverse.v
/re/command-listg
command.V
/re/G
command.w
filewq
fileq
command.w
!command!
command
below). The default filename and current address are unchanged.W
filew
command, except that the
previous contents of file are not clobbered. The current address is
unchanged.x
z
n=
newline
!
command!
, then it is
replaced by text of the previous !command
.
ed
does not process command
for ‘\’ (backslash) escapes. However, an unescaped
‘%’ is replaced by the default filename. When the shell
returns from execution, a ‘!’ is printed to the standard
output. The current line is unchanged.ed
processes file arguments for
backslash escapes, i.e., in a filename, any characters preceded by a backslash
(‘\
’) are interpreted literally.
If a text (non-binary) file is not terminated by a newline
character, then ed
appends one on reading/writing
it. In the case of a binary file, ed
does not append
a newline on reading/writing.
TMPDIR
ed
attempts to write the buffer if the
terminal hangs uped
prints a “?” and
either returns to command mode or exits if its input is from a script. An
explanation of the last error can be printed with the
h
(help) command.
Since the g
(global) command masks any
errors from failed searches and substitutions, it can be used to perform
conditional operations in scripts; e.g.,
g/old/s//new/
replaces any occurrences of old with new.
If the u
(undo) command occurs in a global
command list, then the command list is executed only once.
If diagnostics are not disabled, attempting to quit
ed
or edit another file before writing a modified
buffer results in an error. If the command is entered a second time, it
succeeds, but any changes to the buffer are lost.
USD:09-10
B. W. Kernighan and P. J. Plauger, Software Tools in Pascal, Addison-Wesley, 1981.
ed
command appeared in
Version 1 AT&T UNIX.
April 5, 2018 | NetBSD 9.4 |