|ED(1)||General Commands Manual||ED(1)|
ed — text
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.
ed, any changes not explicitly saved
w command are lost.
Editing is done in two distinct modes:
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:
which replaces all occurrences of the string "old" with "new".
When an input command, such as
i (insert), or
c (change) is
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.
ed commands operate on whole lines or
ranges of lines; e.g., the
d command deletes lines;
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.
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:
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.
ed commands and line addresses
support basic regular expressions (BREs). See
re_format(7) for more
information on regular expressions.
The options are as follows:
edstandard input is from a script.
!’), 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.
An address represents the number of a line in the buffer.
ed maintains a
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 (e.g.,
^’), and whitespace. Addresses are
read from left to right, and their values are computed relative to the
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 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
l (list), or
(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.
!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.
ecommand, except that unwritten changes are discarded without warning. The current address is set to the last line read.
gcommand, the current address is set to the last line affected by command-list. If no lines were matched, the current line number remains unchanged.
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
V. A newline
alone in command-list is equivalent to a
Gcommand, the current address is set to the last line affected by (the last) command-list. If no lines were matched, the current line number remains unchanged.
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.
edscripts begin with this command to aid in debugging.
'lc (i.e., a single quote followed by lc) in subsequent commands. The mark is not cleared until the line is deleted or otherwise modified.
edwaits until the RETURN key is pressed before displaying the next screen. The current address is set to the last line printed.
-pstring, the command prompt is by default turned off.
edunconditionally. This is similar to the
qcommand, except that unwritten changes are discarded without warning.
!command below). The default filename is unchanged. The current address is set to the last line read.
g(global) suffix is given, then every match is replaced. The n suffix, where n is a positive number, causes only the nth match to be replaced. It is an error if no substitutions are performed on any of the addressed lines. The current address is set the last line affected.
re 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 ‘
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
replacement from the last substitution is used.
Newlines may be embedded in replacement if they
are escaped with a backslash
scommand accepts a count suffix n, or any combination of the characters
p. If a count suffix n is given, then only the nth match is replaced. The
rsuffix causes the regular expression of the last search to be used instead of that of the last substitution. The
gsuffix toggles the global suffix of the last substitution. The
psuffix toggles the print suffix of the last substitution. The current address is set to the last line affected.
Vare treated as a single command by undo.
uis its own inverse.
!command below). The default filename and current address are unchanged.
wcommand, except that the previous contents of file are not clobbered. The current address is unchanged.
eddoes 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.
edattempts to write the buffer if the terminal hangs up
ed utility exits 0 on success,
and >0 if an error occurs.
When an error occurs,
ed 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.
g (global) command masks any
errors from failed searches and substitutions, it can be used to perform
conditional operations in scripts; e.g.,
replaces any occurrences of "old" with "new".
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.
B. W. Kernighan and P. J. Plauger, Software Tools in Pascal, 1981, Addison-Wesley.
ed utility is compliant with the
IEEE Std 1003.1-2008 (“POSIX.1”)
The flag [
-x] as well as the commands
z are extensions to that specification.
ed command appeared in
Version 1 AT&T UNIX.
ed processes file
arguments for backslash escapes, i.e., in a filename, any characters
preceded by a backslash (‘
If a text (non-binary) file is not terminated by a newline
ed appends one on reading/writing
it. In the case of a binary file,
ed does not append
a newline on reading/writing.
|September 3, 2010||OpenBSD-5.1|