ed(1) General Commands Manual ed(1)
Name
ed, red - text editor
Syntax
ed [-] [-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
commands, 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 sim-
ulated 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 char-
acters 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 col-
lected. 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:
o An ordinary character (not one of those discussed below) is a one-character RE that matches itself.
o 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 ([]).
b. ^ (caret or circumflex), which is special at the beginning of an entire RE (see below), or when it immediately follows 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.)
o A period (.) is a one-character RE that matches any character except new-line.
o 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 consecutive 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 characters 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:
o A one-character RE is a RE that matches whatever the one-character RE matches.
o 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.
o 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 occur-
rences; {m,n} matches any number of occurrences between m and n inclusive. Whenever a choice exists, the RE matches as many
occurrences as possible.
o The concatenation of REs is a RE that matches the concatenation of the strings matched by each component of the RE.
o A RE enclosed between the character sequences ( and ) is a RE that matches whatever the unadorned RE matches.
o The expression
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 segment or final segment of a line (or both):
o A circumflex (^) at the beginning of an entire RE constrains that RE to match an initial segment of a line.
o 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
constructed 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 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. 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 under-
stood 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. Com-
mands 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 second 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 corre-
spond 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 commands.
(.)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 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, 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 cur-
rent 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 current 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,$)g/RE/command list
In the global command, the first step is to mark every line that matches the given RE. Then, for every such line, the
given command list is executed with . initially set to that line. A single command or the first of a list of commands
appears on the same line as the global command. All lines of a multi-line list except the last line must be ended with
a ; a, i, and c commands and associated input are permitted; the . terminating input mode may be omitted if it would
be the last line of the command list. An empty command list is equivalent to the p command. The g, G, v, and V com-
mands are not permitted in the command list. See also RESTRICTIONS and the last paragraph before FILES below.
(1,$)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 ? diagnostic.
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 (hopefully) 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, preceding each line by its line number and a tab character; . 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.
($)r file
The read command reads in the given file after the addressed line. If no file name is given, the currently-remembered
file name, if any, is used (see e and f commands). The currently-remembered file name is not changed unless file is
the very first file name mentioned since was invoked. Address 0 is legal for r and causes the file to be read at the
beginning of the buffer. If the read is successful, the number of characters read is typed; . is set to the last line
read in. If file is replaced by !, the rest of the line is taken to be a shell (sh(1)) command whose output is to be
read. For example, "$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-overlapped) matched strings are replaced by the replacement if the global replacement indica-
tor 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 current line. The spe-
cial meaning of & in this context may be suppressed by preceding it by . As a more general feature, the characters
, 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 .
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); . 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 buffer, namely the most
recent a, c, d, g, i, j, m, r, s, t, v, G, or V command.
(1,$)v/RE/command list
This command is the same as the global command g except that the command list is executed with . initially set to every
line that does not match the RE.
(1,$)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,$)w file
The write command writes the addressed lines into the named file. If the file does not exist, it is created with mode
666 (readable and writable by everyone), unless your umask setting (see sh(1)) dictates otherwise. The currently-
remembered file name is not changed unless file is the very first file name mentioned since was invoked. If no file
name is given, the currently-remembered file name, if any, is used (see e and f commands); . is unchanged. If the com-
mand is successful, the number of characters written is typed. If file is replaced by !, the rest of the line is taken
to be a shell (sh(1)) command whose standard input is the addressed lines. Such a shell command is not remembered as
the current file name.
($)=
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 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; . 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 use-
ful 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
characters 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 example, /) 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?
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
further information, see
The sequence
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 Also
grep(1), sed(1), sh(1), stty(1)
ed(1)