ed(1) UNIX System V(Essential Utilities) ed(1)
NAME
ed, red - text editor
SYNOPSIS
ed [-s] [-p string ] [-x] [-C] [file]
red [-s] [-p string ] [-x] [-C] [file]
DESCRIPTION
ed is the standard text editor. If the file argument is given, ed
simulates an e command (see below) on the named file; that is to say, the
file is read into ed's buffer so that it can be edited.
-s Suppresses the printing of character counts by e, r, and w
commands, of diagnostics from e and q commands, and of the !
prompt after a !shell command.
-p Allows the user to specify a prompt string.
-x Encryption option; when used, ed simulates an X command and prompts
the user for a key. This key is used to encrypt and decrypt text
using the algorithm of crypt(1). The X command makes an educated
guess to determine whether text read in is encrypted or not. The
temporary buffer file is encrypted also, using a transformed
version of the key typed in for the -x option. See crypt(1).
Also, see the NOTES section at the end of this manual page.
-C Encryption option; the same as the -x option, except that ed
simulates a C command. The C command is like the X command, except
that all text read in is assumed to have been encrypted.
ed operates on a copy of the file it is editing; changes made to the copy
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.
There is only one buffer.
red is a restricted version of ed. It will only allow editing of files
in the current directory. It prohibits executing shell commands via
!shell command. Attempts to bypass these restrictions result in an error
message (restricted shell).
Both ed and red support the fspec(4) formatting capability. After
including a format specification as the first line of file and invoking
ed with your terminal in stty -tabs or stty tab3 mode [see stty(1)], the
specified tab stops will automatically be used when scanning file. For
example, if the first line of a file contained:
<:t5,10,15 s72:>
tab stops would be set at columns 5, 10, and 15, and a maximum line
length of 72 would be imposed. NOTE: when you are entering text into the
file, this format is not in effect; instead, because of being in
stty -tabs or stty tab3 mode, tabs are expanded to every eighth column.
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ed(1) UNIX System V(Essential Utilities) ed(1)
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 that command. These addresses specify one or more lines in
the buffer. Every command that requires addresses has default addresses,
so that the addresses can very often be omitted.
In general, only one command may appear on a line. Certain commands
allow the input of text. This text is placed in the appropriate place in
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 collected.
Leave input mode by typing a period (.) at the beginning of a line,
followed immediately by a carriage return.
ed supports a limited form of regular expression notation; regular
expressions are used in addresses to specify lines and in some commands
(e.g., s) to specify portions of a line that are to be substituted. A
regular expression (RE) specifies a set of character strings. A member
of this set of strings is said to be matched by the RE. The REs allowed
by ed are constructed as follows:
The following one-character REs match a single character:
1.1 An ordinary character (not one of those discussed in 1.2 below) is
a one-character RE that matches itself.
1.2 A backslash (\) followed by any special character is a one-
character RE that matches the special character itself. The
special characters are:
a. ., *, [, and \ (period, asterisk, left square bracket, and
backslash, respectively), which are always special, except
when they appear within square brackets ([]; see 1.4 below).
b. ^ (caret or circumflex), which is special at the beginning
of an entire RE (see 4.1 and 4.3 below), or when it
immediately follows the left of a pair of square brackets
([]) (see 1.4 below).
c. $ (dollar sign), which is special at the end of an entire RE
(see 4.2 below).
d. The character used to bound (i.e., delimit) an entire RE,
which is special for that RE (for example, see how slash (/)
is used in the g command, below.)
1.3 A period (.) is a one-character RE that matches any character
except new-line.
1.4 A non-empty string of characters enclosed in square brackets ([])
is a one-character RE that matches any one character in that
string. If, however, the first character of the string is a
circumflex (^), the one-character RE matches any character except
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ed(1) UNIX System V(Essential Utilities) ed(1)
new-line and the remaining characters in the string. The ^ has
this special meaning only if it occurs first in the string. The
minus (-) may be used to indicate a range of consecutive
characters; for example, [0-9] is equivalent to [0123456789]. The
- loses this special meaning if it occurs first (after an initial
^, if any) or last in the string. The right square bracket (])
does not terminate such a string when it is the first character
within it (after an initial ^, if any); e.g., []a-f] matches
either a right square bracket (]) or one of the ASCII letters a
through f inclusive. The four characters listed in 1.2.a above
stand for themselves within such a string of characters.
The following rules may be used to construct REs from one-character REs:
2.1 A one-character RE is a RE that matches whatever the one-character
RE matches.
2.2 A one-character RE followed by an asterisk (*) is a RE that
matches zero or more occurrences of the one-character RE. If
there is any choice, the longest leftmost string that permits a
match is chosen.
2.3 A one-character RE followed by \{m\}, \{m,\}, or \{m,n\} is a RE
that matches a range of occurrences of the one-character RE. The
values of m and n must be non-negative integers less than 256;
\{m\} matches exactly m occurrences; \{m,\} matches at least m
occurrences; \{m,n\} matches any number of occurrences between m
and n inclusive. Whenever a choice exists, the RE matches as many
occurrences as possible.
2.4 The concatenation of REs is a RE that matches the concatenation of
the strings matched by each component of the RE.
2.5 A RE enclosed between the character sequences \( and \) is a RE
that matches whatever the unadorned RE matches.
2.6 The expression \n matches the same string of characters as was
matched by an expression enclosed between \( and \) earlier in the
same RE. Here n is a digit; the sub-expression specified is that
beginning with the n-th occurrence of \( counting from the left.
For example, the expression ^\(.*\)\1$ matches a line consisting
of two repeated appearances of the same string.
A RE may be constrained to match words.
3.1 \< constrains a RE to match the beginning of a string or to follow
a character that is not a digit, underscore, or letter. The first
character matching the RE must be a digit, underscore, or letter.
3.2 \> constrains a RE to match the end of a string or to precede a
character that is not a digit, underscore, or letter.
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ed(1) UNIX System V(Essential Utilities) ed(1)
An entire RE may be constrained to match only an initial segment or final
segment of a line (or both).
4.1 A circumflex (^) at the beginning of an entire RE constrains that
RE to match an initial segment of a line.
4.2 A dollar sign ($) at the end of an entire RE constrains that RE to
match a final segment of a line.
4.3 The construction ^entire RE$ constrains the entire RE to match the
entire line.
The null RE (e.g., //) is equivalent to the last RE encountered. See
also the last paragraph before FILES below.
To understand addressing in ed it is necessary to know that at any time
there is a current line. Generally speaking, the current line is the
last line affected by a command; the exact effect on the current line is
discussed under the description of each command. Addresses are
constructed as follows:
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ed(1) UNIX System V(Essential Utilities) ed(1)
1. The character . 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 mark name character x, which
must be an ASCII lower-case letter (a-z). Lines are marked with
the k command described below.
5. A RE enclosed by slashes (/) addresses the first line found by
searching forward from the line following the current line toward
the end of the buffer and stopping at the first line containing a
string matching the RE. If necessary, the search wraps around to
the beginning of the buffer and continues up to and including the
current line, so that the entire buffer is searched. See also the
last paragraph before FILES below.
6. A RE enclosed in question marks (?) addresses the first line found
by searching backward from the line preceding the current line
toward the beginning of the buffer and stopping at the first line
containing a string matching the RE. If necessary, the search
wraps around to the end of the buffer and continues up to and
including the current line. See also the last paragraph before
FILES below.
7. An address followed by a plus sign (+) or a minus sign (-)
followed by a decimal number specifies that address plus
(respectively minus) the indicated number of lines. A shorthand
for .+5 is .5.
8. 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.
9. If an address ends with + or -, then 1 is added to or subtracted
from the address, respectively. As a consequence of this rule and
of Rule 8, immediately above, the address - refers to the line
preceding the current line. (To maintain compatibility with
earlier versions of the editor, the character ^ in addresses is
entirely equivalent to -.) Moreover, trailing + and - characters
have a cumulative effect, so -- refers to the current line less 2.
10. For convenience, a comma (,) stands for the address pair 1,$,
while a semicolon (;) stands for the pair .,$.
Commands may require zero, one, or two addresses. Commands that require
no addresses regard the presence of an address as an error. Commands
that accept one or two addresses assume default addresses when an
insufficient number of addresses is given; if more addresses are given
than such a command requires, the last one(s) are used.
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ed(1) UNIX System V(Essential Utilities) ed(1)
Typically, addresses are separated from each other by a comma (,). They
may also be separated by a semicolon (;). In the latter case, the first
address is calculated, the current line (.) is set to that value, and
then the second address is calculated. This feature can be used to
determine the starting line for forward and backward searches (see Rules
5 and 6, above). The second address of any two-address sequence must
correspond to a line in the buffer that follows the line corresponding to
the first address.
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ed(1) UNIX System V(Essential Utilities) ed(1)
In the following list of ed commands, the parentheses shown prior to the
command are not part of the address; rather they show the default
address(es) for the command.
It is generally illegal for more than one command to appear on a line.
However, any command (except e, f, r, or w) may be suffixed by l, n, or p
in which case the current line is either listed, numbered or printed,
respectively, as discussed below under the l, n, and p commands.
(.)a
<text>
.
The append command accepts zero or more lines of text and appends
it after the addressed line in the buffer. The current line (.) is
left at the last inserted line, or, if there were none, at the
addressed line. Address 0 is legal for this command: it causes the
``appended'' text to be placed at the beginning of the buffer. The
maximum number of characters that may be entered from a terminal is
256 per line (including the new-line character).
(.)c
<text>
.
The change command deletes the addressed lines from the buffer,
then accepts zero or more lines of text that replaces these lines
in the buffer. The current line (.) is left at the last line
input, or, if there were none, at the first line that was not
deleted.
C
Same as the X command, described later, except that ed assumes all
text read in for the e and r commands is encrypted unless a null
key is typed in.
(.,.)d
The delete command deletes the addressed lines from the buffer.
The line after the last line deleted becomes the current line; if
the lines deleted were originally at the end of the buffer, the new
last line becomes the current line.
e file
The edit command deletes the entire contents of the buffer and then
reads the contents of file into the buffer. The current line (.)
is set to the last line of the buffer. If file is not given, the
currently remembered file name, if any, is used (see the f
command). The number of characters read in is printed; file is
remembered for possible use as a default file name in subsequent e,
r, and w commands. If file is replaced by !, the rest of the line
is taken to be a shell [sh(1)] command whose output is to be read
in. Such a shell command is not remembered as the current file
name. See also DIAGNOSTICS below.
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ed(1) UNIX System V(Essential Utilities) ed(1)
E file
The Edit command is like e, except that the editor does not check
to see if any changes have been made to the buffer since the last w
command.
f file
If file is given, the file-name command changes the currently
remembered file name to file; otherwise, it prints the currently
remembered file name.
(1,$)g/RE/command list
In the global command, the first step is to mark every line that
matches the given RE. Then, for every such line, the given command
list is executed with the current line (.) initially set to that
line. A single command or the first of a list of commands appears
on the same line as the global command. All lines of a multi-line
list except the last line must be ended with a \; a, i, and c
commands and associated input are permitted. The . terminating
input mode may be omitted if it would be the last line of the
command list. An empty command list is equivalent to the p
command. The g, G, v, and V commands are not permitted in the
command list. See also the NOTES and the last paragraph before
FILES below.
(1,$)G/RE/
In the interactive Global command, the first step is to mark every
line that matches the given RE. Then, for every such line, that
line is printed, the current line (.) is changed to that line, and
any one command (other than one of the a, c, i, g, G, v, and V
commands) may be input and is executed. After the execution of
that command, the next marked line is printed, and so on; a new-
line acts as a null command; an & causes the re-execution of the
most recent command executed within the current invocation of G.
Note that the commands input as part of the execution of the G
command may address and affect any lines in the buffer. The G
command can be terminated by an interrupt signal (ASCII DEL or
BREAK).
h
The help command gives a short error message that explains the
reason for the most recent ? diagnostic.
H
The Help command causes ed to enter a mode in which error messages
are printed for all subsequent ? diagnostics. It will also explain
the previous ? if there was one. The H command alternately turns
this mode on and off; it is initially off.
(.)i
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ed(1) UNIX System V(Essential Utilities) ed(1)
<text>
.
The insert command accepts zero or more lines of text and inserts
it before the addressed line in the buffer. The current line (.)
is left at the last inserted line, or, if there were none, at the
addressed line. This command differs from the a command only in
the placement of the input text. Address 0 is not legal for this
command. The maximum number of characters that may be entered from
a terminal is 256 per line (including the new-line character).
(.,.+1)j
The join command joins contiguous lines by removing the appropriate
new-line characters. If exactly one address is given, this command
does nothing.
(.)kx
The mark command marks the addressed line with name x, which must
be an ASCII lower-case letter (a-z). The address 'x then addresses
this line; the current line (.) is unchanged.
(.,.)l
The list command prints the addressed lines in an unambiguous way:
a few non-printing characters (e.g., tab, backspace) are
represented by visually mnemonic overstrikes. All other non-
printing characters are printed in octal, and long lines are
folded. An l command may be appended to any command other than e,
f, r, or w.
(.,.)ma
The move command repositions the addressed line(s) after the line
addressed by a. Address 0 is legal for a and causes the addressed
line(s) to be moved to the beginning of the file. It is an error
if address a falls within the range of moved lines; the current
line (.) is left at the last line moved.
(.,.)n
The number command prints the addressed lines, preceding each line
by its line number and a tab character; the current line (.) is
left at the last line printed. The n command may be appended to
any command other than e, f, r, or w.
(.,.)p
The print command prints the addressed lines; the current line (.)
is left at the last line printed. The p command may be appended to
any command other than e, f, r, or w. For example, dp deletes the
current line and prints the new current line.
P
The editor will prompt with a * for all subsequent commands. The P
command alternately turns this mode on and off; it is initially
off.
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ed(1) UNIX System V(Essential Utilities) ed(1)
q
The quit command causes ed to exit. No automatic write of a file
is done; however, see DIAGNOSTICS , below.
Q
The editor exits without checking if changes have been made in the
buffer since the last w command.
($)r file
The read command reads the contents of file into the buffer. If
file is not given, the currently remembered file name, if any, is
used (see the e and f commands). The currently remembered file
name is not changed unless file is the very first file name
mentioned since ed was invoked. Address 0 is legal for r and
causes the file to be read in at the beginning of the buffer. If
the read is successful, the number of characters read in is
printed; the current line (.) is set to the last line read in. If
file is replaced by !, the rest of the line is taken to be a shell
[see sh(1)] command whose output is to be read in. For example, $r
!ls appends current directory to the end of the file being edited.
Such a shell command is not remembered as the current file name.
(.,.)s/RE/replacement/ or
(.,.)s/RE/replacement/g or
(.,.)s/RE/replacement/n n = 1-512
The substitute command searches each addressed line for an
occurrence of the specified RE. In each line in which a match is
found, all (non-overlapped) matched strings are replaced by the
replacement if the global replacement indicator g appears after the
command. If the global indicator does not appear, only the first
occurrence of the matched string is replaced. If a number n,
appears after the command, only the n-th occurrence of the matched
string on each addressed line is replaced. It is an error if the
substitution fails on all addressed lines. Any character other
than space or new-line may be used instead of / to delimit the RE
and the replacement; the current line (.) is left at the last line
on which a substitution occurred. See also the last paragraph
before FILES below.
An ampersand (&) appearing in the replacement is replaced by the
string matching the RE on the current line. The special meaning of
& in this context may be suppressed by preceding it by \. As a
more general feature, the characters \n, where n is a digit, are
replaced by the text matched by the n-th regular subexpression of
the specified RE enclosed between \( and \). When nested
parenthesized subexpressions are present, n is determined by
counting occurrences of \( starting from the left. When the
character % is the only character in the replacement, the
replacement used in the most recent substitute command is used as
the replacement in the current substitute command. The % loses its
special meaning when it is in a replacement string of more than one
character or is preceded by a \.
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ed(1) UNIX System V(Essential Utilities) ed(1)
A line may be split by substituting a new-line character into it.
The new-line in the replacement must be escaped by preceding it by
\. Such substitution cannot be done as part of a g or v command
list.
(.,.)ta
This command acts just like the m command, except that a copy of
the addressed lines is placed after address a (which may be 0); the
current line (.) is left at the last line copied.
u
The undo command nullifies the effect of the most recent command
that modified anything in the buffer, namely the most recent a, c,
d, g, i, j, m, r, s, t, v, G, or V command.
(1,$)v/RE/command list
This command is the same as the global command g, except that the
lines marked during the first step are those that do not match the
RE.
(1,$)V/RE/
This command is the same as the interactive global command G,
except that the lines that are marked during the first step are
those that do not match the RE.
(1,$)w file
The write command writes the addressed lines into file. If file
does not exist, it is created with mode 666 (readable and writable
by everyone), unless your file creation mask dictates otherwise;
see the description of the umask special command on sh(1). The
currently remembered file name is not changed unless file is the
very first file name mentioned since ed was invoked. If no file
name is given, the currently remembered file name, if any, is used
(see the e and f commands); the current line (.) is unchanged. If
the command is successful, the number of characters written is
printed. If file is replaced by !, the rest of the line is taken
to be a shell [see sh(1)] command whose standard input is the
addressed lines. Such a shell command is not remembered as the
current file name.
(1,$)W file
This command is the same as the write command above, except that it
appends the addressed lines to the end of file if it exists. If
file does not exist, it is created as described above for the w
command.
X
A key is prompted for, and it is used in subsequent e, r, and w
commands to decrypt and encrypt text using the crypt(1) algorithm.
An educated guess is made to determine whether text read in for the
e and r commands is encrypted. A null key turns off encryption.
Subsequent e, r, and w commands will use this key to encrypt or
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ed(1) UNIX System V(Essential Utilities) ed(1)
decrypt the text [see crypt(1)]. An explicitly empty key turns off
encryption. Also, see the -x option of ed.
($)=
The line number of the addressed line is typed; the current line
(.) is unchanged by this command.
!shell command
The remainder of the line after the ! is sent to the UNIX system
shell [see sh(1)] to be interpreted as a command. Within the text
of that command, the unescaped character % is replaced with the
remembered file name; if a ! appears as the first character of the
shell command, it is replaced with the text of the previous shell
command. Thus, !! will repeat the last shell command. If any
expansion is performed, the expanded line is echoed; the current
line (.) is unchanged.
(.+1)<new-line>
An address alone on a line causes the addressed line to be printed.
A new-line alone is equivalent to .+1p; it is useful for stepping
forward through the buffer.
If an interrupt signal (ASCII DEL or BREAK) is sent, ed prints a ? and
returns to its command level.
Some size limitations: 512 characters in a line, 256 characters in a
global command list, and 64 characters in the pathname of a file
(counting slashes). The limit on the number of lines depends on the
amount of user memory: each line takes 1 word.
When reading a file, ed discards ASCII NUL characters.
If a file is not terminated by a new-line character, ed adds one and puts
out a message explaining what it did.
If the closing delimiter of a RE or of a replacement string (e.g., /)
would be the last character before a new-line, that delimiter may be
omitted, in which case the addressed line is printed. The following
pairs of commands are equivalent:
s/s1/s2 s/s1/s2/p
g/s1 g/s1/p
?s1 ?s1?
FILES
$TMPDIR if this environmental variable is not null, its value is used
in place of /var/tmp as the directory name for the temporary
work file.
/var/tmp if /var/tmp exists, it is used as the directory name for the
temporary work file.
/tmp if the environmental variable TMPDIR does not exist or is
null, and if /var/tmp does not exist, then /tmp is used as
the directory name for the temporary work file.
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ed(1) UNIX System V(Essential Utilities) ed(1)
ed.hup work is saved here if the terminal is hung up.
SEE ALSO
edit(1), ex(1), grep(1), sed(1), sh(1), stty(1), umask(1), vi(1).
fspec(4), regexp(5) in the System Administrator's Reference Manual.
DIAGNOSTICS
? for command errors.
?file for an inaccessible file.
(use the help and Help commands for detailed explanations).
If changes have been made in the buffer since the last w command that
wrote the entire buffer, ed warns the user if an attempt is made to
destroy ed's buffer via the e or q commands. It prints ? and allows one
to continue editing. A second e or q command at this point will take
effect. The -s command-line option inhibits this feature.
NOTES
The - option, although it continues to be supported, has been replaced in
the documentation by the -s option that follows the Command Syntax
Standard [see intro(1)].
The encryption options and commands are provided with the Security
Administration Utilities package, which is available only in the United
States.
A ! command cannot be subject to a g or a v command.
The ! command and the ! escape from the e, r, and w commands cannot be
used if the editor is invoked from a restricted shell [see sh(1)].
The sequence \n in a RE does not match a new-line character.
If the editor input is coming from a command file (e.g., ed file <
ed_cmd_file), the editor exits at the first failure.
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