ed.1

.\"	$MirOS: src/bin/ed/ed.1,v 1.21 2024/01/05 02:08:43 tg Exp $
.\"	$OpenBSD: ed.1,v 1.76 2021/03/08 02:47:26 jsg Exp $
.\"
.\" Copyright (c) 1993 Andrew Moore, Talke Studio.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"-
.\" $miros: contrib/samples/portmdoc,v 1.23 2024/01/04 22:52:50 tg Exp $
.\"-
.\" Copyright © 2008, 2009, 2010, 2016, 2018, 2020, 2023
.\"	mirabilos <m@mirbsd.org>
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.\" Add UCB mdoc compatibility to GNU mdoc
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.\" </MirCVS://contrib/samples/portmdoc>
.\"-
.Dt ED 1
.Os
.Sh NAME
.Nm ed
.Nd the standard text editor
.Sh SYNOPSIS
.Nm ed
.Op Fl
.Op Fl s
.Op Fl p Ar string
.Op Ar file
.Sh DESCRIPTION
.Nm
is a line-oriented text editor.
It is used to create, display, modify and otherwise manipulate text files.
If invoked with a
.Ar file
argument, a copy of
.Ar file
is read into the editor's buffer.
Changes are made to this copy and not directly to
.Ar file
itself.
Upon quitting
.Nm ed ,
any changes not explicitly saved with a
.Ic w
command are lost.
.Pp
Editing is done in two distinct modes:
.Em command
and
.Em input .
When first invoked,
.Nm
is in command mode.
In this mode, commands are read from the standard input and
executed to manipulate the contents of the editor buffer.
.Pp
A typical command might look like:
.Pp
.Dl ,s/old/new/g
.Pp
which replaces all occurrences of the string
.Qq old
with
.Qq new .
.Pp
When an input command, such as
.Ic a
.Pq append ,
.Ic i
.Pq insert ,
or
.Ic c
.Pq change
is given,
.Nm
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
.Pq Ql \&.
on a line.
.Pp
All
.Nm
commands operate on whole lines or ranges of lines; for example, the
.Ic d
command deletes lines, the
.Ic 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
.Ic s
command is applied to whole lines at a time.
.Pp
In general,
.Nm
commands consist of an optional address list followed by a single
character command and possibly additional parameters:
.Pp
.Bd -ragged -offset indent
.Sm off
.Oo Ar address-list Oc Ar command Op Ar parameters
.Ed
.Sm on
.Pp
Some commands do not expect an address list; passing one causes an error.
A number of commands use the right-most address from the list to indicate
the line to be affected by that command; all other commands affect the
range of lines specified by the right-most two addresses.
.Pp
Many
.Nm
commands and line addresses support basic regular expressions
.Pq BREs .
See
.Xr re_format 7
for more information on regular expressions.
.Pp
The options are as follows:
.Bl -tag -width "Xp string"
.It Fl
Same as the
.Fl s
option
.Pq deprecated .
.It Fl p Ar string
Specifies a command prompt.
This may be toggled on and off with the
.Ic P
command.
.It Fl s
Suppress diagnostics.
This should be used if
.Nm
standard input is from a script.
.It Ar file
Specifies the name of a file to read.
If
.Ar file
is prefixed with a
bang
.Pq Ql \&! ,
it is interpreted as a shell command.
In this case, what is read is the standard output of
.Ar file
executed via
.Xr sh 1 .
To read a file whose name begins with a bang, prefix the
name with a backslash
.Pq Ql \e .
The default filename is set to
.Ar file
only if it is not prefixed with a bang.
.El
.Ss LINE ADDRESSING
An address represents the number of a line in the buffer.
The address
.Ad 0
.Pq zero
is an exception to this rule, meaning
.Dq before the first line
and being legal wherever it makes sense.
.Nm
maintains a
.Em 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.
.Pp
A line address is
constructed from one of the bases in the list below, optionally followed
by an offset composed of any combination of operators
.Po
.Ql + ,
.Ql \-
and
.Ql \*(ha
.Pc ,
digits and whitespace.
Addresses are read from left to right, and their values are computed
relative to the current address.
.Pp
Commands (see below) are either prefixed by an address list, in which
case they take the rightmost one or two (depending on the command)
addresses, or not,
in which case attempting to pass one is an error.

in the latter case
Prefixing an
It is
If not, i
.Pp
Address ranges are comprised of at least one separator
.Pq comma or semicolon
optionally surrounded by addresses.
If the address before the first separator is omitted, it defaults to
1 (if the separator is a comma) or the current address (for semicolon).
If any other address is omitted, it defaults to the one calculated for
the position left of the corresponding separator, except if the range
consists of a sole separator it defaults to the last line.
Address ranges yield two or more addresses, which are calculated left
to right; the semicolon separator updates the current address to the
left-hand result before calculating the right-hand address, whereas
each address in comma-separated ranges is interpreted relative to the
initial current address.
.Pp
Commands (see below) expect to be prefixed by zero, one or two addresses.
Address ranges may only be used in front of commands expecting addresses.
If the range contains more addresses than expected, the correct amount is
taken from the right-most ones in the range; this is useful with the
semicolon separator, updating the current address multiple times.
.Pp
The following address symbols are recognised:
.Bl -tag -width Ds
.It \&.
The current line
.Pq address
in the buffer.
.It $
The last line in the buffer.
.It Ar n
The
.Ar n Ns th
line in the buffer, where
.Ar n
is a number in the range
.Ad [0,$] .
.It \- or \*(ha
The previous line.
This is equivalent to
.Ad \-1
and may be repeated with cumulative effect.
.It Xo
.Pf \- Ar n No or\ \&
.Pf \*(ha Ar n
.Xc
The
.Ar n Ns th
previous line, where
.Ar n
is a non-negative number.
.It +
The next line.
This is equivalent to
.Ad +1
and may be repeated with cumulative effect.
.It + Ns Ar n
The
.Ar n Ns th
next line, where
.Ar n
is a non-negative number.
.It \&, or %
The first through last lines in the buffer.
This is equivalent to the address range
.Ad 1,$ .
.It \&;
The current through last lines in the buffer.
This is equivalent to the address range
.Ad .,$ .
.It / Ns Ar re Ns /
The next line containing the regular expression
.Ar re .
The search wraps to the beginning of the buffer and continues down to the
current line, if necessary.
The second slash can be omitted if it ends a line.
.Qq //
repeats the last search.
.It Pf ? Ar re ?
The previous line containing the regular expression
.Ar re .
The search wraps to the end of the buffer and continues up to the
current line, if necessary.
The second question mark can be omitted if it ends a line.
.Qq ??
repeats the last search.
.It \*(aq Ns Ar lc
The line previously marked by a
.Ic k
.Pq mark
command, where
.Ar lc
is a lower case letter.
.El
.Ss COMMANDS
All
.Nm
commands are single characters, though some require additional parameters.
If a command's parameters extend over several lines,
each line except for the last must be terminated with a backslash
.Pq Ql \e .
.Pp
In general, at most one command is allowed per line.
However, most commands accept a print suffix, which is any of
.Ic p
.Pq print ,
.Ic l
.Pq list ,
or
.Ic n
.Pq enumerate ,
to print the last line affected by the command.
.Pp
.Nm
recognises the following commands.
The commands are shown together with
the default address or address range supplied if none is specified
.Pq in parentheses ,
and other possible arguments on the right.
.Bl -tag -width Dxxs
.It (.) Ns Ic 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.
.It (.,.) Ns Ic 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.
.It (.,.) Ns Ic d
Deletes the addressed lines from the buffer.
If there is a line after the deleted range, the current address is set
to this line; otherwise, it is set to the line before the deleted range.
.It Ic e Ar file
Edits
.Ar file
and sets the default filename.
If
.Ar file
is not specified, the default filename is used.
Any lines in the buffer are deleted before the new file is read.
The current address is set to the last line read.
.It Ic e No \&! Ns Ar command
Edits the standard output of
.No \&! Ns Ar command ,
(see
.Ic \&! Ns Ar command
below).
The default filename is unchanged.
Any lines in the buffer are deleted before the output of
.Ar command
is read.
The current address is set to the last line read.
.It Ic E Ar file
Edits
.Ar file
unconditionally.
This is similar to the
.Ic e
command, except that unwritten changes are discarded without warning.
The current address is set to the last line read.
.It Ic f Ar file
Sets the default filename to
.Ar file .
If
.Ar file
is not specified, the default unescaped filename is printed.
.Sm off
.It Xo
.Pf (1,$) Ic g No /
.Ar re No / Ar command-list
.Xc
.Sm on
Mark each addressed line matching the regular expression
.Ar re
for modification.
The current address is set to each marked line in turn, and then the
.Ar command-list
is executed each time.
The command-list can change the current line number,
and it is not changed back after the command-list ended.
When a marked line is changed, it is unmarked
and the command-list won't be executed for it any more.
If no lines were matched,
the current line number remains unchanged.
.Pp
Each command in
.Ar command-list
must be on a separate line,
and every line except for the last must be terminated by a backslash
.Pq Sq \e .
Any commands are allowed, except for
.Ic g ,
.Ic G ,
.Ic v
and
.Ic V .
An empty
.Ar command-list
is equivalent to a
.Ic p
command\*(EMunlike for the
.Cm G
command, where an empty command-list does nothing, and unlike an empty
command, which is equivalent to the command
.Cm +p .
If the
.Ar command-list
is empty, the trailing slash can be omitted.
.Sm off
.It (1,$) Ic G No / Ar re No /
.Sm on
Interactively edits the addressed lines matching a regular expression
.Ar re .
The trailing slash after
.Ar re
can be omitted.
For each matching line, the line is printed, the current address is set,
and the user is prompted to enter a
.Ar command-list .
At the end of the
.Ic G
command, the current address is set to the last line affected by
.Pq the last
command-list.
If no lines were matched,
the current line number remains unchanged.
.Pp
The format of
.Ar command-list
is the same as that of the
.Ic g
command, but an empty command list does nothing.
A single
.Sq &
repeats the last non-empty command list.
.It Ic H
Toggles the printing of error explanations.
By default, explanations are not printed.
It is recommended that
.Nm
scripts begin with this command to aid in debugging.
.It Ic h
Prints an explanation of the last error.
.It (.) Ns Ic 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.
.It (.,+) Ns Ic j
Joins the addressed lines.
The addressed lines are deleted from the buffer and replaced by a single
line containing their joined text.
The current address is set to the resultant line.
.It (.) Ns Ic k Ns Ar lc
Marks a line with a lower case letter
.Ar lc .
The line can then be addressed as
.Ic \*(aq Ns Ar lc
(i.e., a single quote followed by
.Ar lc )
in subsequent commands.
The mark is not cleared until the line is deleted or otherwise modified.
.It (.,.) Ns Ic l
Prints the addressed lines unambiguously.
The current address is set to the last line printed.
.It (.,.) Ns Ic m Ns (.)
Moves lines in the buffer.
The addressed lines are moved to after the
right-hand destination address, which may be the address
.Ad 0
.Pq zero .
The current address is set to the last line moved.
.It (.,.) Ns Ic n
Prints the addressed lines along with their line numbers.
The current address is set to the last line printed.
.It (.,.) Ns Ic p
Prints the addressed lines.
The current address is set to the last line printed.
.It Ic P
Toggles the command prompt on and off.
Unless a prompt was specified with the command-line option
.Fl p Ar string ,
the command prompt is by default turned off.
.It Ic q
Quits
.Nm ed .
.It Ic Q
Quits
.Nm
unconditionally.
This is similar to the
.Ic q
command, except that unwritten changes are discarded without warning.
.It ($) Ns Ic r Ar file
Reads
.Ar file
to after the addressed line.
If
.Ar file
is not specified, the default filename is used.
If no default filename was set prior to the command,
the default filename is set to
.Ar file ;
otherwise, it is unchanged.
The current address is set to the last line read.
.It ($) Ns Ic r No \&! Ns Ar command
Reads to after the addressed line the standard output of
.No \&! Ns Ar command ,
(see
.Ic \&! Ns Ar command
below).
The default filename is unchanged.
The current address is set to the last line read.
.Sm off
.It Xo
.Pf (.,.) Ic s No / Ar re
.No / Ar replacement No /\ \&
.Pf (.,.) Ic s No / Ar re
.No / Ar replacement No / Ic g\ \&
.No (.,.) Ic s No / Ar re
.No / Ar replacement No / Ar n
.Xc
.Sm on
Replaces text in the addressed lines matching a regular expression
.Ar re
with
.Ar replacement .
By default, only the first match in each line is replaced.
If the
.Ic g
.Pq global
suffix is given, every match is replaced.
The
.Ar n
suffix, where
.Ar n
is a positive number, causes only the
.Ar n Ns th
match to be replaced.
It is an error if no substitutions are performed on any of the addressed
lines.
The current address is set the last line affected.
.Pp
.Ar re
and
.Ar replacement
may be delimited by any character other than space and newline
(see the
.Ic s
command below).
If one or two of the last delimiters are omitted, the last line
affected is printed as though the print suffix
.Ic p
were specified.
.Pp
An unescaped
.Ql &
in
.Ar replacement
will substitute the currently matched text.
The character sequence
.Pf \e Ar m ,
where
.Ar m
is a number in the range [1,9], is replaced by the
.Ar m Ns th
backreference expression of the matched text.
If the entire
.Ar replacement
consists of a single
.Ql % ,
the
.Ar replacement
from the last substitution is used.
Newlines may be embedded in
.Ar replacement
if they are escaped with a backslash
.Pq Ql \e .
.It (.,.) Ns Ic s
Repeats the last substitution.
This form of the
.Ic s
command accepts a count suffix
.Ar n ,
or any combination of the characters
.Ic r ,
.Ic g
and
.Ic p .
If a count suffix
.Ar n
is given, only the
.Ar n Ns th
match is replaced.
The
.Ic r
suffix causes the regular expression of the last search to be used
instead of that of the last substitution.
The
.Ic g
suffix toggles the global suffix of the last substitution.
The
.Ic p
suffix toggles the print suffix of the last substitution.
The current address is set to the last line affected.
.It (.,.) Ns Ic t Ns (.)
Copies
.Pq i.e., transfers
the addressed lines to after the right-hand destination address,
which may be the address
.Ad 0
.Pq zero .
The current address is set to the last line copied.
.It Ic u
Undoes the last command and restores the current address
to what it was before the command.
The global commands
.Ic g ,
.Ic G ,
.Ic v
and
.Ic V
are treated as a single command by undo.
.Ic u
is its own inverse.
.Sm off
.It Xo
.Pf (1,$) Ic v No / Ar re
.Pf / Ar command-list
.Xc
.Sm on
The same as the
.Ic g
command, except that it applies
.Ar command-list
to each of the addressed lines not matching the regular expression
.Ar re .
.Sm off
.It Xo
.Pf (1,$) Ic V No /
.Ar re No /
.Xc
.Sm on
The same as the
.Ic G
command, except that it interactively edits the addressed lines
not matching the regular expression
.Ar re .
.It (1,$) Ns Ic w Ar file
Writes the addressed lines to
.Ar file .
Any previous contents of
.Ar file
are lost without warning.
The default filename will be set to
.Ar file
iff it was not set before.
If
.Ar file
was not specified, the default filename is used.
The current address is unchanged.
.It (1,$) Ns Ic wq Ar file
Writes the addressed lines to
.Ar file ,
then executes a
.Ic q
command.
.It (1,$) Ns Ic w No \&! Ns Ar command
Writes the addressed lines to the standard input of
.No \&! Ns Ar command ,
(see
.Ic \&! Ns Ar command
below).
The default filename and current address are unchanged.
.It (1,$) Ns Ic W Ar file
Appends the addressed lines to the end of
.Ar file .
This is similar to the
.Ic w
command, except that the previous contents of file are not clobbered.
The current address is unchanged.
.It (+) Ns Ic z Ns Ar n
Scrolls
.Ar n
lines at a time starting at addressed line.
If
.Ar n
is not specified, the current window size is used.
The current address is set to the last line printed.
.It ($) Ns Ic =
Prints the line number of the addressed line.
.It (+)
An address without a command prints the addressed line
and sets the current address to that line.
If the address is also omitted, it defaults to the next line (+).
.It Ic \&! Ns Ar command
Executes
.Ar command
via
.Xr sh 1 .
If the first character of
.Ar command
is
.Sq \&! ,
it is replaced by text of the previous
.Ic \&! Ns Ar command .
.Nm
does not process
.Ar command
for
.Sq \e
.Pq backslash
escapes.
However, an unescaped
.Sq %
is replaced by the default filename.
When the shell returns from execution, a
.Sq \&!
is printed to the standard output.
The current line is unchanged.
.El
.Sh ASYNCHRONOUS EVENTS
.Bl -tag -width XtmpXedXX
.It Dv SIGHUP
If the current buffer has changed since it was last written,
.Nm
attempts to write the buffer to the file
.Pa ed.hup .
Nothing is written to the currently remembered file, and
.Nm
exits.
.It Dv SIGINT
When an interrupt occurs,
.Nm
prints
.Sq \&?
and a newline, then returns to command mode.
If interrupted during text input,
the text already input is written to the current buffer,
as if text input had been normally terminated.
.It Dv SIGQUIT
This signal is ignored.
.It Dv SIGWINCH
The screen is resized.
.El
.Sh ENVIRONMENT
.Bl -tag -width XtmpXedXX -compact
.It Ev TMPDIR
location to use for temporary files
.El
.Sh FILES
.Bl -tag -width XtmpXedXX -compact
.It Pa /tmp/ed.*
buffer file
.Pq actually in Ev $TMPDIR No if set
.It Pa ed.hup
where
.Nm
attempts to write the buffer if the terminal hangs up
.El
.Sh EXIT STATUS
.Ex -std ed
.Sh DIAGNOSTICS
When an error occurs,
.Nm
prints a
.Sq \&?
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
.Ic h
.Pq help
command.
.Pp
Since the
.Ic g
.Pq global
command masks any errors from failed searches and substitutions,
it can be used to perform conditional operations in scripts; e.g.,
.Pp
.Dl g/old/s//new/
.Pp
replaces any occurrences of
.Qq old
with
.Qq new .
.Pp
If the
.Ic u
.Pq undo
command occurs in a global command list,
the command list is executed only once.
.Pp
If diagnostics are not disabled, attempting to quit
.Nm
or 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.
.Sh SEE ALSO
.Xr sed 1 ,
.Xr sh 1 ,
.Xr vi 1 ,
.Xr re_format 7
.Rs
.\" 4.4BSD USD:9
.%A "B. W. Kernighan"
.%T "A Tutorial Introduction to the UNIX Text Editor"
.%O "09.edtut(USD)"
.Re
.Rs
.\" 4.4BSD USD:10
.%A "B. W. Kernighan"
.%T "Advanced Editing on UNIX"
.%O "10.edadv(USD)"
.Re
.Pp
.Pa http://www.gnu.org/fun/jokes/ed.html
.Pq other implementations, humorous
.Pp
.Pa http://www.gnu.org/fun/jokes/ed\-msg.html
.Pq mandatory read before learning
.Rs
.%A B. W. Kernighan
.%A P. J. Plauger
.%B Software Tools in Pascal
.%O Addison-Wesley
.%D 1981
.Re
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification.
.Pp
The commands
.Cm s
(to repeat the last substitution),
.Cm W ,
.Cm wq
and
.Cm z
as well as the address specifier
.Sq %
are extensions to that specification.
.Pp
The
.St -p1003.1-2008
specification says the
.Sq \*(ha
address specifier is neither required nor prohibited;
additionally, it says behaviour for the
.Fl
option is
.Dq unspecified .
.Sh HISTORY
An
.Nm
command appeared in
.At v1 .
.Sh CAVEATS
.Nm
processes
.Ar file
arguments for backslash escapes, i.e., in a filename,
any characters preceded by a backslash
.Pq Ql \e
are interpreted literally.
.Pp
If a text
.Pq non-binary
file is not terminated by a newline character,
.Nm
appends one on reading/writing it.
In the case of a binary file,
.Nm
does not append a newline on reading/writing.