# EDITOR: ed

ED(1)                                                       ED(1)

NAME
ed - text editor

SYNOPSIS
ed [-] [-sx] [-p string] [file]

DESCRIPTION
ed  is a line-oriented text editor.  It is used to create,
display, modify and otherwise manipulate text files.

If invoked with a file argument, then a copy  of  file  is
copy and not directly to file itself.  Upon  quitting  ed,
any  changes  not explicitly saved  with a w' command are
lost.

Editing is done in two distinct modes: command and  input.
When  first  invoked, ed is in command mode.  In this mode
commands are read from the standard input and executed  to
manipulate  the  contents of the editor buffer.  A typical
command might look like:

,s/old/new/g

which replaces all occurences of the string old with  new.

When  an input command, such as a' (append), i' (insert)
or c' (change), is given, ed enters input mode.  This  is
the primary means of adding text to a file.  In this mode,
no commands are available; instead, the standard input  is
written  directly  to the editor buffer.  Lines consist of
text up to and including a newline character.  Input  mode
is  terminated by entering a single period  (.) on a line.

All ed commands operate on whole lines or ranges of lines;
e.g., the d' command deletes lines; the m' command moves
lines, and so on.  It is possible to modify only a portion
of  a  line  by  means  of  replacement, as in the example
above.  However even here, the s' command is  applied  to
whole lines at a time.

In  general,  ed  commands  consist  of  zero or more line
addresses, followed by a single character command and pos-
sibly  additional  parameters;  i.e.,  commands  have  the
structure:

The address(es) indicate the line or range of lines to  be
affected  by  the  command.   If fewer addresses are given
than the command accepts, then default addresses are  sup-
plied.

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ED(1)                                                       ED(1)

OPTIONS
-s      Suppresses  diagnostics.  This  should  be used if
ed's standard input is from a script.

-x      Prompts for an encryption key to be used in subse-
quent reads and writes (see the x' command).

-p string
Specifies  a  command prompt.  This may be toggled
on and off with the P' command.

file    Specifies the name of a file to read.  If file  is
prefixed  with  a bang (!), then it is interpreted
as a shell command.  In this case, what is read is
the  standard  output  of file executed via sh(1).
To read a file whose name begins with a bang, pre-
fix  the  name  with a backslash (\).  The default
filename is set to file only if it is not prefixed
with a bang.

An  address represents the number of a line in the buffer.
ed maintains a current address which is typically supplied
to commands as the default address when none is specified.
When a file is first read,  the current address is set  to
the  last  line  of  the  file.   In  general, the current
address is set to the last line affected by a command.

A line address is constructed from one of the bases in the
list  below, optionally followed by a numeric offset.  The
offset may include any combination  of  digits,  operators
from left to right, and their values are computed relative

One  exception  to  the rule that addresses represent line
numbers is the address 0 (zero).  This means  "before  the
first line," and is legal wherever it makes sense.

comma or semi-colon. The value of the first address  in  a
range  cannot exceed the value of the second.  If only one
given where n > 2, then the corresponding range is  deter-
mined  by  the last two addresses in the n-tuple.  If only

Each address in a  comma-delimited  range  is  interpreted
relative   to  the  current  address.   In  a  semi-colon-

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ED(1)                                                       ED(1)

delimited range, the first address is used to set the cur-
tive to the first.

The following address symbols are recognized.

.       The current line (address) in the buffer.

$The last line in the buffer. n The nth, line in the buffer where n is a number in the range [0,$].

- or ^  The  previous  line.  This is equivalent to -1 and
may be repeated with cumulative effect.

-n or ^n
The nth previous line, where n is  a  non-negative
number.

+       The  next  line.  This is equivalent to +1 and may
be repeated with cumulative effect.

+n or whitespacen
The nth next line, where n is a non-negative  num-
ber.   whitespace followed by a number n is inter-
preted as +n.

, or %  The first through last lines in the buffer.   This
is equivalent to the address range 1,$. ; The current through last lines in the buffer. This is equivalent to the address range .,$.

/re/    The next line containing  the  regular  expression
re.   The  search  wraps  to  the beginning of the
buffer and continues down to the current line,  if
necessary.  // repeats the last search.

?re?    The  previous  line containing the regular expres-
sion re.  The search  wraps  to  the  end  of  the
buffer  and  continues  up to the current line, if

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ED(1)                                                       ED(1)

necessary.  ?? repeats the last search.

'lc     The line previously marked by a  k'  (mark)  com-
mand, where lc is a lower case letter.

REGULAR EXPRESSIONS
Regular  expressions  are patterns used in selecting text.
For example, the ed command

g/string/

prints all lines containing string.   Regular  expressions
are also used by the s' command for selecting old text to
be replaced with new.

In addition  to  a  specifying  string  literals,  regular
expressions  can  represent  classes  of strings.  Strings
thus represented are said to be matched by the correspond-
ing  regular  expression.  If it is possible for a regular
expression to match several strings in a  line,  then  the
left-most longest match is the one selected.

The  following  symbols  are  used in constructing regular
expressions:

c       Any character c not listed below,  including  {',
'}', (', )', <' and >', matches itself.

\c      Any backslash-escaped character c, except for {',
'}', (', )', <' and >', matches itself.

Matches any single character.

[char-class]
Matches any single character  in  char-class.   To
include a  ]' in char-class, it must be the first
character.  A range of characters may be specified
by separating the end characters of the range with
a -', e.g., a-z' specifies the lower case  char-
acters.   The  following  literal  expressions can
also be used in  char-class  to  specify  sets  of
characters:

[:alnum:]  [:cntrl:]  [:lower:]  [:space:]
[:alpha:]  [:digit:]  [:print:]  [:upper:]
[:blank:]  [:graph:]  [:punct:]  [:xdigit:]

If  -'  appears as the first or last character of

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ED(1)                                                       ED(1)

char-class, then it  matches  itself.   All  other
characters in char-class match themselves.

Patterns in char-class of the form:

[.col-elm.] or,   [=col-elm=]

where  col-elm  is  a collating element are inter-
preted according to locale(5) (not currently  sup-
ported).  See regex(3) for an explanation of these
constructs.

[^char-class]
Matches any single character, other than  newline,
not  in  char-class.   char-class  is  defined  as
above.

^       If ^' is the first character of a regular expres-
sion,  then  it  anchors the regular expression to
the beginning of a line.   Otherwise,  it  matches
itself.

$If $' is the last character of a regular expres-
sion, it anchors the regular expression to the end
of a line.  Otherwise, it matches itself.

\<      Anchors the single character regular expression or
subexpression  immediately  following  it  to  the
beginning of a word.  (This may not be available)

\>      Anchors the single character regular expression or
subexpression immediately following it to the  end
of a word.  (This may not be available)

$$re$$  Defines a subexpression re.  Subexpressions may be
nested.  A subsequent backreference  of  the  form
\n',  where  n  is  a  number in the range [1,9],
expands to the text matched by the nth  subexpres-
sion.    For   example,   the  regular  expression
$$.*$$\1' matches any string consisting of  iden-
ordered relative to their left delimiter.

*       Matches the single character regular expression or
subexpression  immediately  preceding  it  zero or
more times.  If '*' is the first  character  of  a
regular   expression  or  subexpression,  then  it
matches itself.  The *' operator sometimes yields
unexpected  results.   For  example,  the  regular
expression  b*'  matches  the  beginning  of  the
string abbb' (as opposed to the substring bbb'),
since a null match is the only left-most match.

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ED(1)                                                       ED(1)

\{n,m\} or \{n,\} or \{n\}
Matches the single character regular expression or
subexpression  immediately preceding it at least n
and at most m times.  If m  is  omitted,  then  it
matches  at  least  n times.  If the comma is also
omitted, then it matches exactly n times.

Additional regular expression  operators  may  be  defined
depending on the particular regex(3) implementation.

COMMANDS
All ed commands are single characters, though some require
additonal parameters.  If a  command's  parameters  extend
over  several  lines,  then  each line except for the last
must be terminated with a backslash (\).

In general, at most one command is allowed per line.  How-
ever, most commands accept a print suffix, which is any of
p' (print), l' (list) , or n' (enumerate), to print the
last line affected by the command.

An interrupt (typically ^C) has the effect of aborting the
current command and returning the editor to command  mode.

ed  recognizes  the  following commands.  The commands are
supplied if none is specified (in parenthesis).

(.)a    Appends  text  to  the  buffer after the addressed
line.  Text is entered in input mode.  The current
address is set to last line entered.

(.,.)c  Changes  lines in the buffer.  The addressed lines
are deleted from the buffer, and text is  appended
in  their  place.   Text is entered in input mode.
The current address is set to last line entered.

(.,.)d  Deletes the addressed lines from the  buffer.   If
there  is a line after the deleted range, then the
current address is set to this line. Otherwise the
current  address  is  set  to  the line before the
deleted range.

e file  Edits file, and sets  the  default  filename.   If
file  is not specified, then the  default filename
is used.  Any lines  in  the  buffer  are  deleted
is set to the last line read.

e !command
Edits the  standard  output  of  !command',  (see
!command   below).    The   default   filename  is
unchanged.  Any lines in the  buffer  are  deleted
before the output of command is read.  The current

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ED(1)                                                       ED(1)

E file  Edits file unconditionally.  This  is  similar  to
the  e  command, except that unwritten changes are
set to the last line read.

f file  Sets the default filename to file.  If file is not
specified, then the default unescaped filename  is
printed.

(1,$)g/re/command-list Applies command-list to each of the addressed lines matching a regular expression re. The cur- rent address is set to the line currently matched before command-list is executed. At the end of the g' command, the current address is set to the last line affected by command-list. Each command in command-list must be on a separate line, and every line except for the last must be terminated by a backslash (\). Any commands are allowed, except for g', G', v', and V'. A newline alone in command-list is equivalent to a p' command. (1,$)G/re/
Interactively edits the addressed lines matching a
regular expression re.  For  each  matching  line,
the  line  is printed, the current address is set,
and the user is prompted to enter a  command-list.
At the end of the G' command, the current address
is set to the last line  affected  by  (the  last)
command-list.

The  format of command-list is the same as that of
the g' command.  A newline alone acts as  a  null
command  list.  A single &' repeats the last non-
null command list.

H       Toggles the printing of  error  explanations.   By
default, explanations are not printed.  It is rec-
ommended that ed scripts begin with  this  command
to aid in debugging.

h       Prints an explanation of the last error.

(.)i    Inserts  text  in  the  buffer  before the current
line.  Text is entered in input mode.  The current
address is set to the last line entered.

(.,.+1)j
are deleted from the  buffer  and  replaced  by  a

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ED(1)                                                       ED(1)

single  line  containing  their  joined text.  The
current address is set to the resultant line.

(.)klc  Marks a line with a lower  case  letter  lc.   The
line  can then be addressed as 'lc (i.e., a single
quote followed by lc  )  in  subsequent  commands.
The  mark is not cleared until the line is deleted
or otherwise modified.

(.,.)l  Prints the addressed lines  unambiguously.   If  a
single line fills for than one screen (as might be
the  case  when  viewing  a   binary   file,   for
instance),  a  --More--' prompt is printed on the
last line.  ed  waits  until  the  RETURN  key  is
pressed  before  displaying  the next screen.  The
current address is set to the last line printed.

(.,.)m(.)
Moves lines in the buffer.   The  addressed  lines
are  moved  to  after  the  right-hand destination
current address is set to the last line moved.

(.,.)n  Prints  the  addressed lines along with their line
numbers.  The current address is set to  the  last
line printed.

set to the last line printed.

P       Toggles the command prompt on and off.   Unless  a
prompt  was  specified by with command-line option
-p string, the command prompt is by default turned
off.

q       Quits ed.

Q       Quits  ed unconditionally.  This is similar to the
q command, except that unwritten changes are  dis-
carded without warning.

($)r file Reads file to after the addressed line. If file is not specified, then the default filename is used. If there was no default filename prior to the command, then the default filename is set to file. Otherwise, the default filename is unchanged. The current address is set to the last line read. ($)r !command
output of !command', (see  the  !command  below).
The  default  filename  is unchanged.  The current

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ED(1)                                                       ED(1)

(.,.)s/re/replacement/
(.,.)s/re/replacement/g
(.,.)s/re/replacement/n
Replaces text in the addressed  lines  matching  a
regular   expression   re  with  replacement.   By
default, only the first  match  in  each  line  is
replaced.   If  the  g' (global) suffix is given,
then every match to be replaced.  The n'  suffix,
where  n  is a postive number, causes only the nth
match to be replaced.  It is an error if  no  sub-
stitutions  are  performed on any of the addressed
lines.  The current address is set the  last  line
affected.

re and replacement may be delimited by any charac-
ter other than space and newline (see the s' com-
mand below).  If one or two of the last delimiters
is omitted, then the last line affected is printed
as though the print suffix p' were specified.

An unescaped &' in replacement is replaced by the
currently matched text.   The  character  sequence
\m',  where  m is a number in the range [1,9], is
replaced by the mth  backreference  expression  of
the  matched  text.   If replacement consists of a
single %', then replacement from the last substi-
tution  is  used.   Newlines  may  be  embedded in
replacement if they are escaped with  a  backslash
(\).

(.,.)s  Repeats  the  last substitution.  This form of the
s' command accepts a count  suffix  n',  or  any
combination  of  the characters r', g', and p'.
If a count suffix n' is given, then only the  nth
match is replaced.  The r' suffix causes the reg-
ular expression of the  last  search  to  be  used
instead of the that of the last substitution.  The
g' suffix toggles the global suffix of  the  last
substitution.   The  p'  suffix toggles the print
suffix  of  the  last  substitution  The   current
address is set to the last line affected.

(.,.)t(.)
Copies  (i.e.,  transfers)  the addressed lines to
after the right-hand  destination  address,  which
is set to the last line copied.

u       Undoes the last command and restores  the  current
address  to  what  it was before the command.  The
global commands  g',  G',  v',  and  V'.   are

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ED(1)                                                       ED(1)

treated  as  a single command by undo.  u' is its
own inverse.

(1,$)v/pat/command-list Applies command-list to each of the addressed lines not matching a regular expression re. This is similar to the g' command. (1,$)V/re/
Interactively edits the addressed lines not match-
ing  a  regular expression re.  This is similar to
the G' command.

(1,$)w file Writes the addressed lines to file. Any previous contents of file is lost without warning. If there is no default filename, then the default filename is set to file, otherwise it is unchanged. If no filename is specified, then the default filename is used. The current address is unchanged. (1,$)wq file
Writes the addressed lines to file, and then  exe-
cutes a q' command.

(1,$)w !command Writes the addressed lines to the standard input of !command', (see the !command below). The default filename and current address are unchanged. (1,$)W file
Appends the addressed lines to the  end  of  file.
This  is  similar  to the w' command, expect that
the previous contents of file  is  not  clobbered.

x       Prompts  for  an  encryption  key which is used in
subsequent reads and writes.  If a  newline  alone
is  entered  as the key, then encryption is turned
off.  Otherwise, echoing is disabled while  a  key
is  read.  Encryption/decryption is done using the
bdes(1) algorithm.

(.+1)zn Scrolls n lines at a time  starting  at  addressed
line.   If  n  is  not specified, then the current
window size is used.  The current address  is  set
to the last line printed.

!command
Executes  command via sh(1).  If the first charac-
ter of command is !', then it is replaced by text
of  the  previous !command'.  ed does not process

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ED(1)                                                       ED(1)

command for backslash (\)  escapes.   However,  an
unescaped %' is replaced by the default filename.
When the shell returns from execution, a  !'   is
printed  to the standard output.  The current line
is unchanged.

(\$)=    Prints the line number of the addressed line.

(.+1)newline
Prints the addressed line, and  sets  the  current

FILES
/tmp/ed.*           Buffer file
ed.hup              The file to which ed attempts to write
the  buffer if the terminal hangs  up.

vi(1), sed(1), regex(3), bdes(1), sh(1).

USD:12-13

B.  W. Kernighan and P. J. Plauger, Software Tools in Pas-

LIMITATIONS
ed processes file arguments for backslash  escapes,  i.e.,
in  a filename, any characters preceded by a backslash (\)
are interpreted literally.

If a text (non-binary) file is not terminated by a newline
character,  then ed appends one on reading/writing it.  In
the case of a binary file, ed does not append a newline on

DIAGNOSTICS
When  an  error occurs, ed prints a ?' and either returns
to command mode or exits if its input is  from  a  script.
An  explanation  of the last error can be printed with the
h' (help) command.

Since the g' (global)  command   masks  any  errors  from
failed  searches and substitutions, it can be used to per-
form conditional operations in scripts; e.g.,

g/old/s//new/

replaces any occurrences of old  with  new.   If  the  u'
(undo)  command  occurs in a global command list, then the
command list is executed only once.

If diagnostics are not disabled, attempting to quit ed  or

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ED(1)                                                       ED(1)

edit another file before writing a modified buffer results
in an error.  If the command is entered a second time,  it
succeeds, but any changes to the buffer are lost.

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