ex.rm

早期freebsd实现

.\" Copyright (c) 1980, 1993
.\"	The Regents of the University of California.  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.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
.\"
.\"	@(#)ex.rm	8.2 (Berkeley) 4/20/94
.\"
.EH 'USD:12-%''Ex Reference Manual'
.OH 'Ex Reference Manual''USD:12-%'
.de ZP
.nr pd \\n()P
.nr )P 0
.if \\n(.$=0 .IP
.if \\n(.$=1 .IP "\\$1"
.if \\n(.$>=2 .IP "\\$1" "\\$2"
.nr )P \\n(pd
.rm pd
..
.de LC
.br
.sp .1i
.ne 4
.LP
.ta 4.0i
..
.bd S B 3
.\".RP
.TL
Ex Reference Manual
.br
Version 3.7
.AU
William Joy
.AU
Mark Horton
.AI
Computer Science Division
Department of Electrical Engineering and Computer Science
University of California, Berkeley
Berkeley, Ca.  94720
.AB
.I Ex
a line oriented text editor, which supports both command and display
oriented editing.
This reference manual describes the command oriented part of
.I ex;
the display editing features of
.I ex
are described in
.I "An Introduction to Display Editing with Vi."
Other documents about the editor include the introduction
.I "Edit: A tutorial",
the
.I "Ex/edit Command Summary",
and a
.I "Vi Quick Reference"
card.
.AE
.NH 1
Starting ex
.PP
.FS
The financial support of an \s-2IBM\s0 Graduate Fellowship and the National
Science Foundation under grants MCS74-07644-A03 and MCS78-07291 is gratefully
acknowledged.
.FE
Each instance of the editor has a set of options,
which can be set to tailor it to your liking.
The command
.I edit
invokes a version of
.I ex
designed for more casual or beginning
users by changing the default settings of some of these options.
To simplify the description which follows we
assume the default settings of the options.
.PP
When invoked,
.I ex
determines the terminal type from the \s-2TERM\s0 variable in the environment.
It there is a \s-2TERMCAP\s0 variable in the environment, and the type
of the terminal described there matches the \s-2TERM\s0 variable,
then that description
is used.  Also if the \s-2TERMCAP\s0 variable contains a pathname (beginning
with a \fB/\fR) then the editor will seek the description of the terminal
in that file (rather than the default /etc/termcap).
If there is a variable \s-2EXINIT\s0 in the environment, then the editor
will execute the commands in that variable,
otherwise if there is a file
.I \&.exrc
in your \s-2HOME\s0 directory
.I ex
reads commands from that file, simulating a
.I source
command.
Option setting commands placed in
\s-2EXINIT\s0 or
.I \&.exrc
will be executed before each editor session.
.PP
A command to enter
.I ex
has the following prototype:\(dg
.FS
\(dg Brackets `[' `]' surround optional parameters here.
.FE
.DS
\fBex\fP [ \fB\-\fP ] [ \fB\-v\fP ] [ \fB\-t\fP \fItag\fP ] [ \fB\-r\fP ] [ \fB\-l\fP ] [ \fB\-w\fP\fIn\fP ] [ \fB\-x\fP ] [ \fB\-R\fP ] [ \fB+\fP\fIcommand\fP ] name ...
.DE
The most common case edits a single file with no options, i.e.:
.DS
\fBex\fR name
.DE
The
.B \-
command line option
option suppresses all interactive-user feedback
and is useful in processing editor scripts in command files.
The
.B \-v
option is equivalent to using
.I vi
rather than
.I ex.
The
.B \-t
option is equivalent to an initial
.I tag
command, editing the file containing the
.I tag
and positioning the editor at its definition.
The
.B \-r
option is used in recovering after an editor or system crash,
retrieving the last saved version of the named file or,
if no file is specified,
typing a list of saved files.
The
.B \-l
option sets up for editing \s-2LISP\s0, setting the
.I showmatch
and
.I lisp
options.
The
.B \-w
option sets the default window size to
.I n,
and is useful on dialups to start in small windows.
The
.B \-x
option causes
.I ex
to prompt for a
.I key ,
which is used to encrypt and decrypt the contents of the file,
which should already be encrypted using the same key,
see
.I crypt (1).
The
.B \-R
option sets the
.I readonly
option at the start.
.I Name
arguments indicate files to be edited.
An argument of the form
\fB+\fIcommand\fR
indicates that the editor should begin by executing the specified command.
If
.I command
is omitted, then it defaults to ``$'', positioning the editor at the last
line of the first file initially.  Other useful commands here are scanning
patterns of the form ``/pat'' or line numbers, e.g. ``+100'' starting
at line 100.
.NH 1
File manipulation
.NH 2
Current file
.PP
.I Ex
is normally editing the contents of a single file,
whose name is recorded in the
.I current
file name.
.I Ex
performs all editing actions in a buffer
(actually a temporary file)
into which the text of the file is initially read.
Changes made to the buffer have no effect on the file being
edited unless and until the buffer contents are written out to the
file with a
.I write
command.
After the buffer contents are written,
the previous contents of the written file are no longer accessible.
When a file is edited,
its name becomes the current file name,
and its contents are read into the buffer.
.PP
The current file is almost always considered to be
.I edited.
This means that the contents of the buffer are logically
connected with the current file name,
so that writing the current buffer contents onto that file,
even if it exists,
is a reasonable action.
If the current file is not 
.I edited
then
.I ex
will not normally write on it if it already exists.*
.FS
* The
.I file
command will say ``[Not edited]'' if the current file is not considered
edited.
.FE
.NH 2
Alternate file
.PP
Each time a new value is given to the current file name,
the previous current file name is saved as the
.I alternate
file name.
Similarly if a file is mentioned but does not become the current file,
it is saved as the alternate file name.
.NH 2
Filename expansion
.PP
Filenames within the editor may be specified using the normal
shell expansion conventions.
In addition,
the character `%' in filenames is replaced by the
.I current
file name and the character
`#' by the
.I alternate
file name.\(dg
.FS
\(dg This makes it easy to deal alternately with
two files and eliminates the need for retyping the
name supplied on an
.I edit
command after a 
.I "No write since last change"
diagnostic is received.
.FE
.NH 2
Multiple files and named buffers
.PP
If more than one file is given on the command line,
then the first file is edited as described above.
The remaining arguments are placed with the first file in the
.I "argument list."
The current argument list may be displayed with the
.I args
command.
The next file in the argument list may be edited with the
.I next
command.
The argument list may also be respecified by specifying
a list of names to the
.I next
command.
These names are expanded,
the resulting list of names becomes the new argument list,
and
.I ex
edits the first file on the list.
.PP
For saving blocks of text while editing, and especially when editing
more than one file,
.I ex
has a group of named buffers.
These are similar to the normal buffer, except that only a limited number
of operations are available on them.
The buffers have names
.I a
through
.I z.\(dd
.FS
\(dd It is also possible to refer to
.I A
through
.I Z;
the upper case buffers are the same as the lower but commands
append to named buffers rather than replacing
if upper case names are used.
.FE
.NH 2
Read only
.PP
It is possible to use
.I ex
in
.I "read only"
mode to look at files that you have no intention of modifying.
This mode protects you from accidently overwriting the file.
Read only mode is on when the
.I readonly
option is set.
It can be turned on with the
.B \-R
command line option,
by the
.I view
command line invocation,
or by setting the
.I readonly
option.
It can be cleared by setting
.I noreadonly .
It is possible to write, even while in read only mode, by indicating
that you really know what you are doing.
You can write to a different file, or can use the ! form of write,
even while in read only mode.
.NH 1
Exceptional Conditions
.NH 2
Errors and interrupts
.PP
When errors occur
.I ex
(optionally) rings the terminal bell and, in any case, prints an error
diagnostic.  If the primary input is from a file, editor processing
will terminate.  If an interrupt signal is received,
.I ex
prints ``Interrupt'' and returns to its command level.  If the primary
input is a file, then
.I ex
will exit when this occurs.
.NH 2
Recovering from hangups and crashes
.PP
If a hangup signal is received and the buffer has been modified since
it was last written out, or if the system crashes, either the editor
(in the first case) or the system (after it reboots in the second) will
attempt to preserve the buffer.  The next time you log in you should be
able to recover the work you were doing, losing at most a few lines of
changes from the last point before the hangup or editor crash.  To
recover a file you can use the
.B \-r
option.  If you were editing the file
.I resume,
then you should change
to the directory where you were when the crash occurred, giving the command
.DS
\fBex \-r\fP\fI resume\fP
.DE
After checking that the retrieved file is indeed ok, you can
.I write
it over the previous contents of that file.
.PP
You will normally get mail from the system telling you when a file has
been saved after a crash.  The command
.DS
\fBex\fP \-\fBr\fP
.DE
will print a list of the files which have been saved for you.
(In the case of a hangup,
the file will not appear in the list,
although it can be recovered.)
.NH 1
Editing modes
.PP
.I Ex
has five distinct modes.  The primary mode is
.I command
mode.  Commands are entered in command mode when a `:' prompt is
present, and are executed each time a complete line is sent.  In
.I "text input"
mode
.I ex
gathers input lines and places them in the file.  The
.I append,
.I insert,
and
.I change
commands use text input mode.
No prompt is printed when you are in text input mode.
This mode is left by typing a `.' alone at the beginning of a line, and
.I command
mode resumes.
.PP
The last three modes are
.I open
and
.I visual
modes, entered by the commands of the same name, and, within open and
visual modes
.I "text insertion"
mode.
.I Open
and
.I visual
modes allow local editing operations to be performed on the text in the
file.  The
.I open
command displays one line at a time on any terminal while
.I visual
works on \s-2CRT\s0 terminals with random positioning cursors, using the
screen as a (single) window for file editing changes.
These modes are described (only) in
.I "An Introduction to Display Editing with Vi."
.NH 
Command structure
.PP
Most command names are English words,
and initial prefixes of the words are acceptable abbreviations.
The ambiguity of abbreviations is resolved in favor of the more commonly
used commands.*
.FS
* As an example, the command 
.I substitute
can be abbreviated `s'
while the shortest available abbreviation for the 
.I set
command is `se'.
.FE
.NH 2
Command parameters
.PP
Most commands accept prefix addresses specifying the lines in the file
upon which they are to have effect.
The forms of these addresses will be discussed below.
A number of commands also may take a trailing
.I count
specifying the number of lines to be involved in the command.\(dg
.FS
\(dg Counts are rounded down if necessary.
.FE
Thus the command ``10p'' will print the tenth line in the buffer while
``delete 5'' will delete five lines from the buffer,
starting with the current line.
.PP
Some commands take other information or parameters,
this information always being given after the command name.\(dd
.FS
\(dd Examples would be option names in a
.I set
command i.e. ``set number'',
a file name in an
.I edit
command,
a regular expression in a
.I substitute
command,
or a target address for a
.I copy
command, i.e. ``1,5 copy 25''.
.FE
.NH 2
Command variants
.PP
A number of commands have two distinct variants.
The variant form of the command is invoked by placing an
`!' immediately after the command name.
Some of the default variants may be controlled by options;
in this case, the `!' serves to toggle the default.
.NH 2
Flags after commands
.PP
The characters `#', `p' and `l' may be placed after many commands.**
.FS
**
A `p' or `l' must be preceded by a blank or tab
except in the single special case `dp'.
.FE
In this case, the command abbreviated by these characters
is executed after the command completes.
Since
.I ex
normally prints the new current line after each change, `p' is rarely necessary.
Any number of `+' or `\-' characters may also be given with these flags.
If they appear, the specified offset is applied to the current line
value before the printing command is executed.
.NH 2
Comments
.PP
It is possible to give editor commands which are ignored.
This is useful when making complex editor scripts
for which comments are desired.
The comment character is the double quote: ".
Any command line beginning with " is ignored.
Comments beginning with " may also be placed at the ends
of commands, except in cases where they could be confused as part
of text (shell escapes and the substitute and map commands).
.NH 2
Multiple commands per line
.PP
More than one command may be placed on a line by separating each pair
of commands by a `|' character.
However the
.I global
commands,
comments,
and the shell escape `!'
must be the last command on a line, as they are not terminated by a `|'.
.NH 2
Reporting large changes
.PP
Most commands which change the contents of the editor buffer give
feedback if the scope of the change exceeds a threshold given by the
.I report
option.
This feedback helps to detect undesirably large changes so that they may
be quickly and easily reversed with an
.I undo.
After commands with more global effect such as
.I global
or
.I visual,
you will be informed if the net change in the number of lines
in the buffer during this command exceeds this threshold.
.NH 1
Command addressing
.NH 2
Addressing primitives
.IP \fB.\fR 20
The current line.
Most commands leave the current line as the last line which they affect.
The default address for most commands is the current line,
thus `\fB.\fR' is rarely used alone as an address.
.IP \fIn\fR 20
The \fIn\fRth line in the editor's buffer, lines being numbered
sequentially from 1.
.IP \fB$\fR 20
The last line in the buffer.
.IP \fB%\fR 20
An abbreviation for ``1,$'', the entire buffer.
.IP \fI+n\fR\ \fI\-n\fR 20