ed(1)ed(1)Name
ed, red - text editor
Syntaxed [-] [-pstring] [-x] [file]
red [-] [-x] [file]
Description
The text editor is the standard text editor. If you give the file
argument, simulates an e command (see below) on the named file; that is
to say, the file is read into buffer so that it can be edited. The -
option suppresses the printing of character counts by e, r, and w com‐
mands, of diagnostics from e and q commands, and of the ! prompt after
a !shell command. The -p option allows you to specify a prompt string.
The -x option is available only if the Encryption layered product is
installed. If you supply the -x option, an x command is simulated
first to handle an encrypted file. The text editor operates on a copy
of the file it is editing; changes made to the copy have no effect on
the file until you give a w (write) command. The copy of the text
being edited resides in a temporary file called the buffer. There is
only one buffer.
The text editor is a restricted version of It allows editing of files
only in the current directory, and prohibits executing shell commands
with !shell command. Attempts to bypass these restrictions result in
an error message (restricted shell). When you enter text, tab charac‐
ters are expanded to every eighth column as is the default.
Commands to 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 frequently be omitted.
In general, only one command appears on a line. Certain commands allow
the input of text. This text is placed in the appropriate place in the
buffer. While is accepting text, it is said to be in input mode. In
input mode, no commands are recognized; all input is merely collected.
Input mode is exited by typing a period (.) alone at the beginning of a
line.
The text editor supports a limited form of regular expression notation;
regular expressions are used in addresses to specify lines and in some
commands (for example, 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 are constructed as follows:
The following one-character REs match a single character:
· An ordinary character (not one of those discussed below) is a
one-character RE that matches itself.
· A backslash (\) followed by any special character is a one-char‐
acter 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 ([]).
b. ^ (caret or circumflex), which is special at the beginning
of an entire RE (see below), or when it immediately fol‐
lows the left of a pair of square brackets ([]) (see
below).
c. $ (currency symbol), which is special at the end of an
entire RE (see below).
d. The character used to bound (that is, delimit) an entire
RE, which is special for that RE (for example, see how
slash (/) is used in the g command, below.)
· A period (.) is a one-character RE that matches any character
except new-line.
· 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 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 con‐
secutive ASCII 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). For example, []a-f] matches either a right square bracket
(]) or one of the letters a through f inclusive. The four char‐
acters listed in a above stand for themselves within such a
string of characters.
The following rules may be used to construct REs from one-character
REs:
· A one-character RE is a RE that matches whatever the one-charac‐
ter RE matches.
· 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.
· 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.
· The concatenation of REs is a RE that matches the concatenation
of the strings matched by each component of the RE.
· A RE enclosed between the character sequences \( and \) is a RE
that matches whatever the unadorned RE matches.
· 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.
Finally, an entire RE may be constrained to match only an initial seg‐
ment or final segment of a line (or both):
· A circumflex (^) at the beginning of an entire RE constrains
that RE to match an initial segment of a line.
· A currency symbol ($) at the end of an entire RE constrains that
RE to match a final segment of a line.
The construction ^entire RE$ constrains the entire RE to match the
entire line.
The null RE (for example, //) is equivalent to the last RE encountered.
See also the last paragraph before FILES below.
To understand addressing in 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 con‐
structed as follows:
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 a lower-case letter. 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 con‐
taining 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 para‐
graph before FILES below.
7. An address followed by a plus sign (+) or a minus sign (-) fol‐
lowed by a decimal number specifies that address plus (respec‐
tively minus) the indicated number of lines. The plus sign may
be omitted.
8. If an address begins with + or -, the addition or subtraction is
taken with respect to the current line. For example, -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.
Typically, addresses are separated from each other by a comma (,).
They may also be separated by a semicolon (;). In the latter case, the
current line (.) is set to the first address, and only then is the sec‐
ond address 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 that follows, in the buffer, the line corresponding to the
first address.
In the following list of commands, the default addresses are shown in
parentheses. The parentheses are not part of the address; they show
that the given addresses are the default.
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 com‐
mands.
(.)a
<text>
. The append command reads the given text and appends
it after the addressed line; . is left at the last
inserted line, or, if there were none, at the
addressed line. Address 0 is legal for this com‐
mand: 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,
then accepts input text that replaces these lines;
. is left at the last line input, or, if there were
none, at the first line that was not deleted.
(.,.)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 causes the entire contents of the
buffer to be deleted, and then the named file to be
read in; . is set to the last line of the buffer.
If no file name is given, the currently-remembered
file name, if any, is used (see the f command).
The number of characters read is typed; 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.
Such a shell command is not remembered as the cur‐
rent file name. See also DIAGNOSTICS below.
E file
The 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,$)g/RE/command list
In the global command, the first step is to mark
every line that matches the given RE. Then, for
every such line, the given command list is executed
with . initially set to that line. A single com‐
mand or the first of a list of commands appears on
the same line as the global command. All lines of
a multi-line list except the last line must be
ended with a \; a, i, and c commands and associated
input are permitted; the . terminating input mode
may be omitted if it would be the last line of the
command list. An empty command list is equivalent
to the p command. The g, G, v, and V commands are
not permitted in the command list. See also
RESTRICTIONS and the last paragraph before FILES
below.
(1,$)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, .
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 ? diagnos‐
tic.
H
The help command causes 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
<text>
.
The insert command inserts the given text before
the addressed 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 a lower-case letter. The address
′x then addresses this line; . is unchanged.
(.,.)l
The list command prints the addressed lines in an
unambiguous way: a few non-printing characters (for
example, tab, backspace) are represented by (hope‐
fully) mnemonic overstrikes, all other non-printing
characters are printed in octal, and long lines are
folded. An l command may be appended to any other
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; .
is left at the last line moved.
(.,.)n
The number command prints the addressed lines, pre‐
ceding each line by its line number and a tab char‐
acter; . is left at the last line printed. The n
command may be appended to any other command other
than e, f, r, or w.
(.,.)p
The print command prints the addressed lines; . is
left at the last line printed. The p command may
be appended to any other 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.
q
The quit command causes to exit. No automatic
write of a file is done (but see DIAGNOSTICS
below).
Q
The editor exits without checking if changes have
been made in the buffer since the last w command.
($)r file
The read command reads in the given file after the
addressed line. If no file name is given, the cur‐
rently-remembered file name, if any, is used (see e
and f commands). The currently-remembered file
name is not changed unless file is the very first
file name mentioned since was invoked. Address 0
is legal for r and causes the file to be read at
the beginning of the buffer. If the read is suc‐
cessful, the number of characters read is typed; .
is set to the last line read in. If file is
replaced by !, the rest of the line is taken to be
a shell (sh(1)) command whose output is to be read.
For example, "$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
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-over‐
lapped) 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. It is an error for the
substitution to fail on all addressed lines. Any
character other than space or new-line may be used
instead of / to delimit the RE and the replacement;
. 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 cur‐
rent line. The special meaning of & in this con‐
text 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 parenthe‐
sized 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 \.
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 substi‐
tution 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); . is left at the last
line of the copy.
u
The undo command nullifies the effect of the most
recent command that modified anything in the buf‐
fer, namely the most recent a, c, d, g, i, j, m, r,
s, t, v, G, or V command.
(1,$)v/RE/command list
This command is the same as the global command g
except that the command list is executed with .
initially set to every line that does not match the
RE.
(1,$)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,$)w file
The write command writes the addressed lines into
the named file. If the file does not exist, it is
created with mode 666 (readable and writable by
everyone), unless your umask setting (see sh(1))
dictates otherwise. The currently-remembered file
name is not changed unless file is the very first
file name mentioned since was invoked. If no file
name is given, the currently-remembered file name,
if any, is used (see e and f commands); . is
unchanged. If the command is successful, the num‐
ber of characters written is typed. If file is
replaced by !, the rest of the line is taken to be
a shell (sh(1)) command whose standard input is the
addressed lines. Such a shell command is not
remembered as the current file name.
($)=
The line number of the addressed line is typed; .
is unchanged by this command.
!shell command
The remainder of the line after the ! is sent to
the UNIX System shell (sh(1)) to be interpreted as
a command. Within the text of that command, the
unescaped character % is replaced with the remem‐
bered file name; if a ! appears as the first char‐
acter 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; . 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, prints a ? and
returns to its command level.
Some size limitations: 512 characters per line, 256 characters per
global command list, 64 characters per file name, and 128K characters
in the buffer. The limit on the number of lines depends on the amount
of user memory: each line takes 1 word.
When reading a file, discards ASCII NUL characters and all characters
after the last new-line. Files (for example, a.out) that contain char‐
acters not in the ASCII set (bit 8 on) cannot be edited by
If the closing delimiter of a RE or of a replacement string (for exam‐
ple, /) would be the last character before a new-line, that delimiter
may be omitted, in which case the addressed line is printed. The fol‐
lowing pairs of commands are equivalent:
s/s1/s2 s/s1/s2/p
g/s1 g/s1/p
?s1 ?s1?
Restrictions
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 the editor is invoked from a restricted shell. For fur‐
ther information, see
The sequence \n in a RE does not match a new-line character.
The l command mishandles DEL.
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, warns the user if an attempt is made to
destroy 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 - command-line option inhibits this feature.
Files
/tmp/e# temporary; # is the process number.
ed.hup work is saved here if the terminal is hung up.
See Alsogrep(1), sed(1), sh(1), stty(1)ed(1)