ed.1

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)ed.1	8.2	12/3/90
.if t .ds ^ \^\s+4\v@.3m@^\v@-.3m@\s-4\^
.if n .ds ^ ^
.TH ed 1
.SH Name
ed, red \- text editor
.SH Syntax 
.B ed
[\fB\-\fR] [\fB\-p\fIstring\fR] [\fB\-x\fR] [\|\fIfile\fR\|]
.PP
.B red
[\fB\-\fR] [\fB\-x\fR] [\|\fIfile\fR\|]
.SH Description
.NXR "editors" "ed"
.NXR "editors" "red"
.NXR "ed line editor"
.NXR "red line editor"
The
.PN ed
text editor 
is the standard text editor.
If you give the
.I file\^
argument,
.PN ed
simulates an
.B e
command (see below) on the named file; that is to say,
the file is read into
.PN ed 's
buffer so that it can be edited.
The 
.B \-
option suppresses the printing
of character counts by
.IR e ,
.IR r ,
and
.B w
commands,
of diagnostics from
.B e
and
.B q
commands,
and of the
.B !
prompt after a
\fB!\fP\fIshell\ command\^\fP.
The \fB\-p\fR option allows you to specify a prompt string.
.NT
The 
.B \-x
option is available only if the Encryption 
layered product is installed.
.NE
If you supply the 
.B \-x
option, an
.B x
command is simulated first to handle an encrypted file.
The 
.PN ed
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
.B w
(write)
command.
The copy of the text being edited resides
in a temporary file called the
.IR buffer .
There is only
one buffer.
.PP
The
.PN red
text editor
is a restricted version of
.PN ed .
It allows editing of files only in the current directory,
and prohibits executing shell commands with
\fB!\fP\fIshell\ command\^\fP.
Attempts to bypass these restrictions result
in an error message \fI(restricted shell)\fP.
.NT
When you enter
text, tab characters are expanded to every eighth column as is the
default.
.NE
.PP
Commands to
.PN ed
have a simple and regular structure: zero, one, or two
.I 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.
.PP
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
.PN ed
is accepting text, it is said
to be in
.IR "input mode" .
In input mode,
no commands are recognized;
all input is merely collected.
Input mode is exited by typing a period (\^\fB.\fP\^) alone at the
beginning of a line.
.PP
The
.PN ed
text editor supports a limited form of
.I "regular expression\^"
notation;
regular expressions are used in addresses to specify
lines and in some commands
(for example,
.IR s )
to specify portions of a line that are to be substituted.
A regular expression (\s-1RE\s+1) specifies
a set of character strings.
A member of this set of strings is said to be
.I matched\^
by the \s-1RE\s+1.
The \s-1RE\s+1s allowed by
.PN ed
are constructed as follows:
.NXR "ed line editor" "constructing regular expressions"
.PP
The following
.I one-character\^
.IR \s-1RE\s+1 s
match a
.I single\^
character:
.IP \(bu
An ordinary character
(\c
.I not\^
one of those discussed below)
is a
one-character \s-1RE\s+1
that matches itself.
.IP \(bu
A backslash (\fB\^\e\fP) followed by any special character is a
one-character \s-1RE\s+1
that matches the special character itself.
The special characters are:
.RS
.TP "\w'a.\ \ \ \ 'u"
a.
\&\fB.\fP,
\fB\(**\fP,
\fB[\fP,
and
\fB\^\e\fP (period, asterisk, left square bracket,
and backslash, respectively), which are always special,
.I except\^
when they appear within square brackets (\^\fB[\|]\fP\^).
.TP
b.
\*^ (caret or circumflex), which is special at the
.I beginning\^
of an
.I entire\^
\s-1RE\s+1
(see below),
or when it immediately follows the left of a pair of square
brackets (\^\fB[\|]\fP\^) (see below).
.TP
c.
\fB$\fP (currency symbol), which is special at the
.I end\^
of an
entire \s-1RE\s+1
(see below).
.TP
d.
The character used to bound
(that is, delimit)
an entire \s-1RE\s+1, which is special for that RE (for example,
see how slash (\^\fB/\fP\^) is used in the
.B g
command, below.)
.RE
.IP \(bu
A period (\^\fB.\fP\^) is a
one-character \s-1RE\s+1
that matches any character except new-line.
.IP \(bu
A non-empty string of characters enclosed in square brackets (\^\fB[\|]\fP\^) is a
one-character \s-1RE\s+1
that matches
.I "any one\^"
character in that string.
If, however, the first character of the string is a circumflex
(\*^), the
one-character \s-1RE\s+1
matches any character
.I except\^
new-line and the remaining characters in the string.
The \*^ has this special meaning
.I only\^
if it
occurs first in the string.
The minus (\fB\-\fP) may be used to indicate a range of consecutive
ASCII characters;
for example, \fB[0\-9]\fP is equivalent to \fB[0123456789]\fP.
The \fB\-\fP loses this special meaning if it occurs first (after
an initial \*^, if any)
or last in the string.
The right square bracket (\^\fB]\fP\^)
does not terminate such a string when it
is the first character within it (after an initial \*^, if any).
For example,
\fB[\|]a\-f]\fP matches either a right square
bracket (\^\fB]\fP\^) or one of
the letters \fBa\fP through \fBf\fP inclusive.
The four characters listed in a above stand for themselves
within such a string of characters.
.PP
The following rules may be used to construct
.IR \s-1RE\s+1 s
from one-character
\s-1RE\s+1s:
.IP \(bu
A one-character \s-1RE\s+1
is a
\s-1RE\s+1
that matches whatever the
one-character \s-1RE\s+1 matches.
.IP \(bu
A
one-character \s-1RE\s+1
followed by an asterisk (\fB\(**\fP) is a
\s-1RE\s+1
that matches
.I zero\^
or more occurrences of the
one-character \s-1RE\s+1.
If there is any choice,
the longest leftmost string that permits a match is chosen.
.IP \(bu
A
one-character \s-1RE\s+1
followed by \fB\^\e{\fP\^\fIm\fP\^\fB\e}\fP,
\fB\^\e{\fP\^\fIm,\fP\^\fB\e}\fP,
or
\fB\^\e{\fP\^\fIm,n\fP\^\fB\e}\fP is a
\s-1RE\s+1
that matches a
.I range\^
of occurrences of the
one-character \s-1RE\s+1.
The values of
.I m\^
and
.I n\^
must be non-negative integers less than 256;
\fB\^\e{\fP\^\fIm\fP\^\fB\e}\fP
matches
.I exactly\^
.I m\^
occurrences;
\fB\^\e{\fP\^\fIm,\fP\^\fB\e}\fP
matches
.I "at least\^"
.I m\^
occurrences;
\fB\^\e{\fP\^\fIm,n\fP\^\fB\e}\fP
matches
.I "any number\^"
of occurrences
.I between\^
.I m\^
and
.I n\^
inclusive.
Whenever a choice exists,
the
\s-1RE\s+1
matches as many occurrences as possible.
.IP \(bu
The concatenation of
\s-1RE\s+1s
is a
\s-1RE\s+1
that matches the concatenation of the strings matched by each component of the
\s-1RE\s+1.
.IP \(bu
A
\s-1RE\s+1
enclosed between the character sequences
\fB\^\e(\fP and \fB\^\e)\fP
is a
\s-1RE\s+1
that matches whatever the unadorned
\s-1RE\s+1
matches.
.IP \(bu
The expression \fB\^\e\fP\fIn\fP\^ matches the same string of characters
as was
matched by an expression enclosed between \fB\^\e(\fP and \fB\^\e)\fP
.I earlier\^
in the same \s-1RE\s+1.
Here
.I n\^
is a digit;
the sub-expression specified is that beginning with the
.IR n \-th
occurrence of \fB\^\e(\fP counting from the left.
For example, the expression \*^\fB\e(.\(**\e)\e1$\fP matches a line
consisting of two repeated appearances of the same string.
.PP
Finally, an
.I entire\^
.I \s-1RE\s+1\^
may be constrained to match only an initial segment or final segment
of a line (or both):
.IP \(bu
A circumflex (\*^) at the beginning of an
entire \s-1RE\s+1
constrains that \s-1RE\s+1 to match an
.I initial\^
segment of a line.
.IP \(bu
A currency symbol (\^\fB$\fP\^)
at the end of an
entire \s-1RE\s+1
constrains that
\s-1RE\s+1
to match a
.I final\^
segment of a line.
.PP
The construction
\%\*^\fIentire \s-1RE\s+1\fP\|\fB$\fP
constrains the
entire \s-1RE\s+1
to match the entire line.
.PP
The null \s-1RE\s+1 (for example, \fB//\fP)
is equivalent to the last \s-1RE\s+1 encountered.
See also the last paragraph before
FILES
below.
.PP
To understand addressing in
.PN ed
it is necessary to know that at any time there is a
.IR "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.
.I Addresses\^
are constructed as follows:
.NXR "ed line editor" "constructing addresses"
.TP "\w'1.1\ \ \ \ 'u"
\01.
The character \fB.\fP addresses the current line.
.TP
\02.
The character \fB$\fP addresses the last line of the buffer.
.TP
\03.
A decimal number
.I n\^
addresses the
.IR n \-th
line of the buffer.
.TP
\04.
\fI\(fmx\fP\^ addresses the line marked with the
mark name character
.IR x ,
which must be a lower-case letter.
Lines are marked with the
.B k
command described below.
.TP
\05.
A \s-1RE\s+1 enclosed by slashes (\^\fB/\fP\^) addresses
the first line found by searching
.I forward\^
from the line
.I following\^
the current line
toward the end of the
buffer and stopping at the first line containing a
string matching the \s-1RE\s+1.
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.
.TP
\06.
A \s-1RE\s+1 enclosed in question marks (\^\fB?\fP\^) addresses
the first line found by searching
.I backward\^
from the line
.I preceding\^
the current line
toward the beginning of
the buffer and stopping at the first line containing
a string matching the \s-1RE\s+1.
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.
.TP
\07.
An address followed by a plus sign (\^\fB+\fP\^)
or a minus sign (\fB\-\fP) followed by a decimal number specifies that address plus
(respectively minus) the indicated number of lines.
The plus sign may be omitted.
.TP
\08.
If an address begins with \fB+\fP or \fB\-\fP,
the addition or subtraction is taken with respect to the current line.
For example, \fB\-5\fP is understood to mean \fB.\-5\fP.
.TP
\09.
If an address ends with \fB+\fP or \fB\-\fP,
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 \fB\-\fP 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 \fB\-\fP.)
Moreover,
trailing
\fB+\fP and \fB\-\fP characters
have a cumulative effect, so \fB\-\-\fP refers to the current
line less 2.
.TP
10.
For convenience, a comma (\^\fB,\fP\^) stands for the
address pair \fB1,\^$\fP,
while a semicolon (\^\fB;\fP\^) stands for the
pair \fB.\^,\^$\fP.
.br
.if \n()s .bp
.PP
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.
.PP
Typically, addresses are separated from each other by a comma
(\^\fB,\fP\^).
They may also be separated by a semicolon
(\^\fB;\fP\^).
In the latter case, the current line (\^\fB.\fP\^) 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 correspond to a line that follows, in the buffer, the line corresponding to the first address.
.PP
In the following list of
.PN ed
commands, the default addresses
are shown in parentheses.
.NXR "ed line editor" "command list"
The parentheses are
.I not\^
part of
the address; they show that the given addresses are
the default.
.PP
It is generally illegal for more than one
command to appear on a line.
However, any command
(except
.B e,
.B f,
.B r,
or
.B w)
may be suffixed by \fBl\fP, \fBn\fP
or \fBp\fP, in which case
the current line is either
listed, numbered or printed, respectively,
as discussed below under the
.B l,
.B n
and
.B p
commands.
.TP 20
.B (\|.\|)a
.ns
.TP
<text>
.ns
.TP
\&\fB.\fP
The append
command reads the given text
and appends it after the addressed line;
\&\fB.\fP 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).
.HP
.B (\|.\|)c
.br
.ns
.HP
<text>
.br
.ns
.HP
.if t .rs
.if t .sp -.5v
\&\fB.\fP
.br
The change
command deletes the addressed lines, then accepts input
text that replaces these lines;
\&\fB.\fP is left at the last line input, or, if there were none,
at the first line that was not deleted.
.HP
.B (\|.\|,\|.\|)d
.br
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.
.HP
.BI e " file\^"
.br
The edit
command causes the entire contents of the buffer to be deleted,
and then the named file to be read in;
\&\fB.\fP 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
.B f
command).
The number of characters read is typed;
.I file\^
is remembered for possible use as a default file name
in subsequent
.B e,
.B r,
and
.B w "commands."
If
.I file\^
is replaced by \fB!\fP, 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
.B not
remembered as the current file name.
See also
DIAGNOSTICS
below.
.HP
.BI E " file\^"
.br
The 
.PN edit
command is like
.B e,
except that the editor does not check to see
if any changes have been made to the buffer since
the last
.B w
command.
.HP
.BI f " file\^"
.br
If
.I file\^
is given,
the file-name
command changes
the currently-remembered file name to
.IR file ;
otherwise, it prints the currently-remembered file name.
.HP
.BI (\|1\|,\|$\|)g/ \s-1RE\s+1 / "command list\^"
.br
In the global
command, the first step is to mark every line that matches
the given
\s-1RE\s+1.
Then, for every such line, the