ED(1) BSD ED(1)
NAME
ed, red - text editor
SYNOPSIS
ed [ -s ] [ -p string ] [file]
red [ -s ] [ -p string ] [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, the file
is read into ed's buffer so that it can be edited.
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 only allows editing of files in
the current directory. It prohibits executing shell commands using the
!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)),
specified tab stops are automatically 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: while inputing text, tab
characters when typed are expanded to every eighth column as is the
default.
OPTIONS
-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. Also, see the WARNING section
at the end of this manual page.
-p Allows you to specify a prompt string. 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.
| -x Simulate an x command first to handle an encrypted
| file.
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. Input mode is
left by typing a period (.) alone 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
(s, for example) 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.
REGULAR EXPRESSIONS
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:
- ., *, [, and \ (period, asterisk, left square bracket, and
backslash, respectively), which are always special, except when
they appear within square brackets.
- ^ (caret or circumflex), which is special at the beginning of an
entire RE, or immediately follows the left of a pair of square
brackets.
- $ (dollar sign), which is special at the end of an entire RE.
- 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.)
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); e.g.,
[]a-f] matches either a right square bracket (]) or one of the 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:
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 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.
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 \n matches the same string of characters as was matched
by an expression enclosed between \( and \) 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 dollar sign ($) at the end of an entire RE constrains that RE to
match a final segment of a line.
The construction ^entire RE$ constrains the entire RE to match the entire
line.
The null RE (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:
- The character . addresses the current line.
- The character $ addresses the last line of the buffer.
- A decimal number n addresses the n-th line of the buffer.
- '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.
- 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.
- 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.
- 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.
- 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.
- If an address ends with + or -, then 1 is added to or subtracted
from the address, respectively. As a consequence of this rule and
the rule 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.
- For convenience, a comma (,) stands for the address pair 1,$,
while a semicolon (;) stands for the pair .,$.
COMMANDS
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 second
address calculated. This feature can be used to
determine the starting line for forward and backward searches. 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 ed 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 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 current file name. See also DIAGNOSTICS
below.
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,$)g/RE/command list
In the global command, the first step is to mark every line that
matches the given RE. Then, for every such line, the given command
list is executed with . initially set to that line. A single
command or the first of a list of commands appears on the same line
as the global command. All lines of a multi-line list except the
last line must be ended with a \; a, i, and c commands and
associated input are permitted. The . terminating input mode may be
omitted if it would be the last line of the command list. An empty
command list is equivalent to the p command. The g, G, v, and V
commands are not permitted in the command list. See also BUGS and
the last paragraph before FILES below.
(1,$)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 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
<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 (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 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 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.
($)r file
The read command reads in the given file after the addressed line.
If no file name is given, the currently-remembered file name, if
any, is used (see e and f commands). The currently-remembered file
name is not changed unless file is the very first file name
mentioned since ed was invoked. Address 0 is legal for r and causes
the file to be read at the beginning of the buffer. If the read is
successful, the number of characters read is typed; . is set to the
last line read in. If file is replaced by !, the rest of the line
is taken to be a shell (sh(1)) command whose output is to be read.
For example, "$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 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 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 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 \.
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,$)w file
The write command writes the addressed lines into the named file.
If the file does not exist, it is created with mode 666 (readable
and writable by everyone), unless your umask setting (see umask(1))
dictates otherwise. The currently-remembered file name is not
changed unless file is the very first file name mentioned since ed
was invoked. If no file name is given, the currently-remembered
file name, if any, is used (see e and f commands); . is unchanged.
If the command is successful, the number of c haracters written is
typed. If file is replaced by !, the rest of the line is taken to
be a shell (sh(1)) command whose standard input is the addressed
lines. Such a shellcommand is not remembered as the current file
name.
($)=
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 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 per line, 256 characters per
global command list, and 64 characters per file name. 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. Files (e.g.,
a.out) that contain characters not in the ASCII set (bit 8 on) cannot be
edited by ed.
If a file is not terminated by a new-line character, ed adds one and
outputs 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
/usr/tmp Default directory for temporary work file.
$TMPDIR If this environmental variable is not null, its value is used
in place of /usr/tmp as the directory name for the temporary
work file.
ed.hup Work is saved here if the terminal is hung up.
/lib/chrclass/*
DIAGNOSTICS
? Command error.
? file An inaccessible file.
(use the help command 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.
NOTE
ed has user-settable character classes. See chrtbl(1M), ctype(3C), and
environ(5).
WARNINGS
The - option, although supported in this release for upward
compatibility, will no longer be supported in the next major release of
the system. Convert shell scripts that use the - option to use the -s
option, instead.
BUGS
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.
Characters are masked to 7 bits on input.
If the editor input is coming from a command file (e.g., ed file < ed-
cmd-file), the editor will exit at the first failure.
SEE ALSO
edit(1), ex(1), grep(1), sed(1), sh(1), stty(1), umask(1), vi(1), crypt(1).
chrtbl(1M).
ctype(3C).
fspec(4).
environ(5), regexp(5) in the SysV Programmer's Reference.
Updated 1/94