ED(1) BSD General Commands Manual ED(1)
NAME
ed, red -- text editor
SYNOPSIS
ed [-] [-sx] [-p string] [file]
red [-] [-sx] [-p string] [file]
DESCRIPTION
The ed utility is a line-oriented text editor. It is used to create, display, modify and otherwise
manipulate text files. When invoked as red, the editor runs in "restricted" mode, in which the only
difference is that the editor restricts the use of filenames which start with `!' (interpreted as shell
commands by ed) or contain a `/'. Note that editing outside of the current directory is only prohib-ited prohibited
ited if the user does not have write access to the current directory. If a user has write access to
the current directory, then symbolic links can be created in the current directory, in which case red
will not stop the user from editing the file that the symbolic link points to.
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 replace-ment, replacement,
ment, 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.
OPTIONS
The following options are available:
-s Suppress diagnostics. This should be used if ed's standard input is from a script.
-x Prompt for an encryption key to be used in subsequent reads and writes (see the x command).
-p string
Specify a command prompt. This may be toggled on and off with the P command.
file Specify the name of a file to read. If file is prefixed with a bang (!), then it is inter-preted interpreted
preted 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.
LINE ADDRESSING
An address represents the number of a line in the buffer. The ed utility 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 semicolon-delimited
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:
. The current line (address) in the buffer.
$ The last line in the buffer.
n The nth, line in the buffer where n is a number in the range [0,$].
- or ^ The previous line. This is equivalent to -1 and may be repeated with cumulative effect.
-n or ^n
The nth previous line, where n is a non-negative number.
+ The next line. This is equivalent to +1 and may be repeated with cumulative effect.
+n The nth next line, where n is a non-negative number.
, or % The first through last lines in the buffer. This is equivalent to the address range 1,$.
; The current through last lines in the buffer. This is equivalent to the address range .,$.
/re/ The next line containing the regular expression re. The search wraps to the beginning of the
buffer and continues down to the current line, if necessary. // repeats the last search.
?re? The previous line containing the regular expression re. The search wraps to the end of the
buffer and continues up to the current line, if necessary. ?? repeats the last search.
'lc The line previously marked by a k (mark) command, where lc is a lower case letter.
REGULAR EXPRESSIONS
Regular expressions are patterns used in selecting text. For example, the 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 a 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 pos-sible possible
sible for a regular expression to match several strings in a line, then the left-most longest match is
the one selected.
The following symbols are used in constructing regular expressions:
c Any character c not listed below, including `{', `}', `(', `)', `<' and `>', matches itself.
\c Any backslash-escaped character c, except for `{', `}', `(', `)', `<' and `>', matches itself.
. Match any single character.
[char-class]
Match any single character in char-class. To include a `]' in char-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 literal
expressions can also be used in char-class to specify sets of characters:
[:alnum:] [:cntrl:] [:lower:] [:space:]
[:alpha:] [:digit:] [:print:] [:upper:]
[:blank:] [:graph:] [:punct:] [:xdigit:]
If `-' appears as the first or last character of char-class, then it matches itself. All other
characters in char-class match themselves.
Patterns in char-class of the form:
[.col-elm.] or,
[=col-elm=]
where col-elm is a collating element are interpreted according to the current locale settings
(not currently supported). See regex(3) and re_format(7) for an explanation of these con-structs. constructs.
structs.
[^char-class]
Match any single character, other than newline, not in char-class. Char-class is defined as
above.
^ If ^ is the first character of a regular expression, then it anchors the regular expression to
the beginning of a line. Otherwise, it matches itself.
$ If $ is the last character of a regular expression, it anchors the regular expression to the
end of a line. Otherwise, it matches itself.
\< Anchor the single character regular expression or subexpression immediately following it to the
beginning of a word. (This may not be available)
\> Anchor the single character regular expression or subexpression immediately following it to the
end of a word. (This may not be available)
\(re\) Define a subexpression re. Subexpressions may be nested. A subsequent backreference of the
form \n, where n is a number in the range [1,9], expands to the text matched by the nth subex-pression. subexpression.
pression. For example, the regular expression `\(.*\)\1' matches any string consisting of
identical adjacent substrings. Subexpressions are ordered relative to their left delimiter.
* Match the single character regular expression or subexpression immediately preceding it zero or
more times. If * is the first character of a regular expression or subexpression, then it
matches itself. The * operator sometimes yields unexpected results. For example, the regular
expression `b*' matches the beginning of the string `abbb' (as opposed to the substring `bbb'),
since a null match is the only left-most match.
\{n,m\} or \{n,\} or \{n\}
Match the single character regular expression or subexpression immediately preceding it at
least n and at most m times. If m is omitted, then it matches at least n times. If the comma
is also omitted, then it matches exactly n times.
Additional regular expression operators may be defined depending on the particular regex(3) implementa-tion. implementation.
tion.
COMMANDS
All 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.
The ed utility recognizes the following commands. The commands are shown together with the default
address or address range supplied if none is specified (in parenthesis).
(.)a Append text to the buffer after the addressed line. Text is entered in input mode. The cur-rent current
rent address is set to last line entered.
(.,.)c Change lines in the buffer. The addressed lines are deleted from the buffer, and text is
appended in their place. Text is entered in input mode. The current address is set to last
line entered.
(.,.)d Delete the addressed lines from the buffer. If there is a line after the deleted range, then
the current address is set to this line. Otherwise the current address is set to the line
before the deleted range.
e file Edit file, and sets the default filename. If file is not specified, then the default filename
is used. Any lines in the buffer are deleted before the new file is read. The current address
is set to the last line read.
e !command
Edit the standard output of !command, (see !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 file Edit file unconditionally. This is similar to the e command, except that unwritten changes are
discarded without warning. The current address is set to the last line read.
f file Set the default filename to file. If file is not specified, then the default unescaped file-name filename
name is printed.
(1,$)g/re/command-list
Apply command-list to each of the addressed lines matching a regular expression re. The cur-rent current
rent address is set to the line currently matched before command-list is executed. At the end
of the g 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.
(1,$)G/re/
Interactively edit the addressed lines matching a regular expression re. For each matching
line, the line is printed, the current address is set, and the user is prompted to enter a
command-list. At the end of the 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 Toggle the printing of error explanations. By default, explanations are not printed. It is
recommended that ed scripts begin with this command to aid in debugging.
h Print an explanation of the last error.
(.)i Insert text in the buffer before the current line. Text is entered in input mode. The current
address is set to the last line entered.
(.,.+1)j
Join the addressed lines. The addressed lines are deleted from the buffer and replaced by a
single line containing their joined text. The current address is set to the resultant line.
(.)klc Mark a line with a lower case letter lc. The line can then be addressed as '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.
(.,.)l Print the addressed lines unambiguously. If a single line fills for than one screen (as might
be the case when viewing a binary file, for instance), a ``--More--'' prompt is printed on the
last line. The ed utility waits until the RETURN key is pressed before displaying the next
screen. The current address is set to the last line printed.
(.,.)m(.)
Move lines in the buffer. The addressed lines are moved to after the right-hand destination
address, which may be the address 0 (zero). The current address is set to the last line moved.
(.,.)n Print the addressed lines along with their line numbers. The current address is set to the
last line printed.
(.,.)p Print the addressed lines. The current address is set to the last line printed.
P Toggle the command prompt on and off. Unless a prompt was specified by with command-line
option -p string, the command prompt is by default turned off.
q Quit ed.
Q Quit ed unconditionally. This is similar to the q command, except that unwritten changes are
discarded without warning.
($)r file
Read file to after the addressed line. If file is not specified, then the default filename is
used. If there was no default filename prior to the command, then the default filename is set
to file. Otherwise, the default filename is unchanged. The current address is set to the last
line read.
($)r !command
Read to after the addressed line the standard output of !command, (see the !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/n
Replace text in the addressed lines matching a regular expression re with replacement. By
default, only the first match in each line is replaced. If the g (global) suffix is given,
then every match to be 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 `&' 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 m th 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 Repeat the last substitution. This form of the s command accepts a count suffix n, or any com-bination combination
bination 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 the that of the last substitution. The g suffix toggles the global suffix of the last sub-stitution. substitution.
stitution. The p suffix toggles the print suffix of the last substitution The current address
is set to the last line affected.
(.,.)t(.)
Copy (i.e., transfer) the addressed lines to after the right-hand destination address, which
may be the address 0 (zero). The current address is set to the last line copied.
u Undo the last command and restores the current address to what it was before the command. The
global commands g, G, v, and V. are treated as a single command by undo. u is its own
inverse.
(1,$)v/re/command-list
Apply command-list to each of the addressed lines not matching a regular expression re. This
is similar to the g command.
(1,$)V/re/
Interactively edit the addressed lines not matching a regular expression re. This is similar
to the G command.
(1,$)w file
Write the addressed lines to file. Any previous contents of file is lost without warning. If
there is no default filename, then the default filename is set to file, otherwise it is
unchanged. If no filename is specified, then the default filename is used. The current
address is unchanged.
(1,$)wq file
Write the addressed lines to file, and then executes a q command.
(1,$)w !command
Write the addressed lines to the standard input of !command, (see the !command below). The
default filename and current address are unchanged.
(1,$)W file
Append the addressed lines to the end of file. This is similar to the w command, expect that
the previous contents of file is not clobbered. The current address is unchanged.
x Prompt for an encryption key which is used in subsequent reads and writes. If a newline alone
is entered as the key, then encryption is turned off. Otherwise, echoing is disabled while a
key is read. Encryption/decryption is done using the bdes(1) algorithm.
(.+1)zn
Scroll n lines at a time starting at addressed line. If n is not specified, then the current
window size is used. The current address is set to the last line printed.
!command
Execute command via sh(1). If the first character of command is `!', then it is replaced by
text of the previous !command. The ed utility 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.
($)= Print the line number of the addressed line.
(.+1)newline
Print the addressed line, and sets the current address to that line.
FILES
/tmp/ed.* buffer file
ed.hup the file to which ed attempts to write the buffer if the terminal hangs up
DIAGNOSTICS
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.
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.
SEE ALSO
bdes(1), sed(1), sh(1), vi(1), regex(3), compat(5)
USD:12-13
B. W. Kernighan and P. J. Plauger, Software Tools in Pascal, 1981, Addison-Wesley.
LIMITATIONS
The ed utility processes file arguments for backslash escapes, i.e., in a filename, any characters pre-ceded preceded
ceded by a backslash (\) are interpreted literally.
If a text (non-binary) file is not terminated by a newline character, then ed appends one on read-ing/writing reading/writing
ing/writing it. In the case of a binary file, ed does not append a newline on reading/writing.
per line overhead: 4 ints
HISTORY
An ed command appeared in Version 1 AT&T UNIX.
BUGS
The ed utility does not recognize multibyte characters.
BSD July 3, 2004 BSD
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