This is ed.info, produced by makeinfo version 4.13+ from ed.texi.

INFO-DIR-SECTION Basics
START-INFO-DIR-ENTRY
* Ed: (ed).                     The GNU line editor
END-INFO-DIR-ENTRY

   Copyright (C) 1993, 1994, 2006-2020 Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.


File: ed.info,  Node: Top,  Next: Overview,  Up: (dir)

The GNU ed line editor
**********************

This manual is for GNU ed (version 1.16, 20 February 2020).

* Menu:

* Overview::                        Overview of the 'ed' command
* Introduction to line editing::    Getting started with GNU 'ed'
* Invoking ed::                     Command line interface
* Line addressing::                 Specifying lines/ranges in the buffer
* Regular expressions::             Patterns for selecting text
* Commands::                        Commands recognized by GNU 'ed'
* Limitations::                     Intrinsic limits of GNU 'ed'
* Diagnostics::                     GNU 'ed' error handling
* Problems::                        Reporting bugs
* GNU Free Documentation License::  How you can copy and share this manual


   Copyright (C) 1993, 1994, 2006-2020 Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.


File: ed.info,  Node: Overview,  Next: Introduction to line editing,  Prev: Top,  Up: Top

1 Overview
**********

GNU ed is a line-oriented text editor. It is used to create, display,
modify and otherwise manipulate text files, both interactively and via
shell scripts. A restricted version of ed, red, can only edit files in
the current directory and cannot execute shell commands. Ed is the
'standard' text editor in the sense that it is the original editor for
Unix, and thus widely available. For most purposes, however, it is
superseded by full-screen editors such as GNU Emacs or GNU Moe.

   GNU ed is based on the editor algorithm described in Brian W.
Kernighan and P. J. Plauger's book "Software Tools in Pascal",
Addison-Wesley, 1981.

   If invoked with a FILE argument, then a copy of FILE is read into
the editor's buffer. Changes are made to this 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. A
"line" consists of the 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 possibly additional
parameters; i.e., commands have the structure:

     [ADDRESS[,ADDRESS]]COMMAND[PARAMETERS]

   The ADDRESSes 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 supplied.


File: ed.info,  Node: Introduction to line editing,  Next: Invoking ed,  Prev: Overview,  Up: Top

2 Introduction to line editing
******************************

'ed' was created, along with the Unix operating system, by Ken Thompson
and Dennis Ritchie. It is the refinement of its more complex,
programmable predecessor, 'QED', to which Thompson and Ritchie had
already added pattern matching capabilities (*note Regular
expressions::).

   For the purposes of this tutorial, a working knowledge of the Unix
shell 'sh' and the Unix file system is recommended, since 'ed' is
designed to interact closely with them.  (*Note GNU bash manual:
(bash)Top, for details about bash).

   The principal difference between line editors and display editors is
that display editors provide instant feedback to user commands, whereas
line editors require sometimes lengthy input before any effects are
seen. The advantage of instant feedback, of course, is that if a mistake
is made, it can be corrected immediately, before more damage is done.
Editing in 'ed' requires more strategy and forethought; but if you are
up to the task, it can be quite efficient.

   Much of the 'ed' command syntax is shared with other Unix utilities.

   As with the shell, <RETURN> (the carriage-return key) enters a line
of input. So when we speak of "entering" a command or some text in
'ed', <RETURN> is implied at the end of each line. Prior to typing
<RETURN>, corrections to the line may be made by typing either
<BACKSPACE> to erase characters backwards, or <CONTROL>-u (i.e., hold
the CONTROL key and type u) to erase the whole line.

   When 'ed' first opens, it expects to be told what to do but doesn't
prompt us like the shell. So let's begin by telling 'ed' to do so with
the <P> ("prompt") command:

     $ ed
     P
     *

   By default, 'ed' uses asterisk ('*') as command prompt to avoid
confusion with the shell command prompt ('$').

   We can run Unix shell ('sh') commands from inside 'ed' by prefixing
them with <!> (exclamation mark, aka "bang"). For example:

     *!date
     Mon Jun 26 10:08:41 PDT 2006
     !
     *!for s in hello world; do echo $s; done
     hello
     world
     !
     *

   So far, this is no different from running commands in the Unix shell.
But let's say we want to edit the output of a command, or save it to a
file. First we must capture the command output to a temporary location
called a "buffer" where 'ed' can access it. This is done with 'ed''s
<r> command (mnemonic: "read"):

     *r !cal -m
     137
     *

   Here 'ed' is telling us that it has just read 137 characters into
the editor buffer - i.e., the output of the 'cal' command, which prints
a simple ASCII calendar. To display the buffer contents we issue the
<p> ("print") command (not to be confused with the prompt command,
which is uppercase!). To indicate the range of lines in the buffer that
should be printed, we prefix the command with <,> (comma) which is
shorthand for "the whole buffer":

     *,p
           June 2006
     Mo Tu We Th Fr Sa Su
               1  2  3  4
      5  6  7  8  9 10 11
     12 13 14 15 16 17 18
     19 20 21 22 23 24 25
     26 27 28 29 30

     *

   Now let's write the buffer contents to a file named 'junk' with the
<w> ("write") command:

     *w junk
     137
     *

   Need we say? It's good practice to frequently write the buffer
contents, since unwritten changes to the buffer will be lost when we
exit 'ed'.

   The sample sessions below illustrate some basic concepts of line
editing with 'ed'. We begin by creating a file, 'sonnet', with some
help from Shakespeare. As with the shell, all input to 'ed' must be
followed by a <newline> character. Commands beginning with '#' are
taken as comments and ignored. Input mode lines that begin with '#' are
just more input.

     $ ed
     # The 'a' command is for appending text to the editor buffer.
     a
     No more be grieved at that which thou hast done.
     Roses have thorns, and filvers foutians mud.
     Clouds and eclipses stain both moon and sun,
     And loathsome canker lives in sweetest bud.
     .
     # Entering a single period on a line returns 'ed' to command mode.
     # Now write the buffer to the file 'sonnet' and quit:
     w sonnet
     183
     # 'ed' reports the number of characters written.
     q
     $ ls -l
     total 2
     -rw-rw-r--    1 alm           183 Nov 10 01:16 sonnet
     $

   In the next example, some typos are corrected in the file 'sonnet'.

     $ ed sonnet
     183
     # Begin by printing the buffer to the terminal with the 'p' command.
     # The ',' means "all lines".
     ,p
     No more be grieved at that which thou hast done.
     Roses have thorns, and filvers foutians mud.
     Clouds and eclipses stain both moon and sun,
     And loathsome canker lives in sweetest bud.
     # Select line 2 for editing.
     2
     Roses have thorns, and filvers foutians mud.
     # Use the substitute command, 's', to replace 'filvers' with 'silver',
     # and print the result.
     s/filvers/silver/p
     Roses have thorns, and silver foutians mud.
     # And correct the spelling of 'fountains'.
     s/utia/untai/p
     Roses have thorns, and silver fountains mud.
     w sonnet
     183
     q
     $

   Since 'ed' is line-oriented, we have to tell it which line, or range
of lines we want to edit. In the above example, we do this by
specifying the line's number, or sequence in the buffer. Alternatively,
we could have specified a unique string in the line, e.g., '/filvers/',
where the '/'s delimit the string in question.  Subsequent commands
affect only the selected line, a.k.a. the "current" line. Portions of
that line are then replaced with the substitute command, whose syntax
is 's/OLD/NEW/'.

   Although 'ed' accepts only one command per line, the print command
'p' is an exception, and may be appended to the end of most commands.

   In the next example, a title is added to our sonnet.

     $ ed sonnet
     183
     a
      Sonnet #50
     .
     ,p
     No more be grieved at that which thou hast done.
     Roses have thorns, and silver fountains mud.
     Clouds and eclipses stain both moon and sun,
     And loathsome canker lives in sweetest bud.
      Sonnet #50
     # The title got appended to the end; we should have used '0a'
     # to append "before the first line".
     # Move the title to its proper place.
     5m0p
      Sonnet #50
     # The title is now the first line, and the current address has been
     # set to the address of this line as well.
     ,p
      Sonnet #50
     No more be grieved at that which thou hast done.
     Roses have thorns, and silver fountains mud.
     Clouds and eclipses stain both moon and sun,
     And loathsome canker lives in sweetest bud.
     wq sonnet
     195
     $

   When 'ed' opens a file, the current address is initially set to the
address of the last line of that file. Similarly, the move command 'm'
sets the current address to the address of the last line moved.

   Related programs or routines are 'vi (1)', 'sed (1)', 'regex (3)',
'sh (1)'. Relevant documents are:

     Unix User's Manual Supplementary Documents: 12 -- 13

     B. W. Kernighan and P. J. Plauger: "Software Tools in Pascal",
     Addison-Wesley, 1981.


File: ed.info,  Node: Invoking ed,  Next: Line addressing,  Prev: Introduction to line editing,  Up: Top

3 Invoking ed
*************

The format for running 'ed' is:

     ed [OPTIONS] [FILE]
     red [OPTIONS] [FILE]

   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, prefix the name with a
backslash ('\'). The default filename is set to FILE only if it is not
prefixed with a bang.

   'ed' supports the following options:

'-h'
'--help'
     Print an informative help message describing the options and exit.

'-V'
'--version'
     Print the version number of 'ed' on the standard output and exit.
     This version number should be included in all bug reports.

'-G'
'--traditional'
     Forces backwards compatibility. This affects the behavior of the
     'ed' commands 'G', 'V', 'f', 'l', 'm', 't' and '!!'. If the
     default behavior of these commands does not seem familiar, then
     try invoking 'ed' with this switch.

'-l'
'--loose-exit-status'
     Don't exit with bad status if a command happens to "fail" (for
     example if a substitution command finds nothing to replace). This
     can be useful when 'ed' is invoked as the editor for crontab.

'-p STRING'
'--prompt=STRING'
     Specifies a command prompt string and turns prompting on. Showing
     the prompt string may be toggled on and off with the 'P' command.

'-r'
'--restricted'
     Run in restricted mode. This mode disables editing of files out of
     the current directory and execution of shell commands.

'-s'
'--quiet'
'--silent'
     Suppresses diagnostics, the printing of byte counts by 'e', 'E',
     'r' and 'w' commands, and the '!' prompt after a '!' command. This
     option may be useful if 'ed''s standard input is from a script.

'-v'
'--verbose'
     Verbose mode; prints error explanations. This may be toggled on
     and off with the 'H' command.


   Exit status: 0 if no errors occurred; otherwise >0.


File: ed.info,  Node: Line addressing,  Next: Regular expressions,  Prev: Invoking ed,  Up: Top

4 Line addressing
*****************

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 address of the last line of the
file. In general, the current address is set to the address of the last
line affected by a command.

   One exception to the rule that addresses represent line numbers is
the address '0' (zero). This means "at the beginning of the buffer",
and is valid wherever it makes sense.

   An address range is two addresses separated either by a comma (',')
or a semicolon (';'). In a semicolon-delimited range, the current
address ('.') is set to the first address before the second address is
calculated. This feature can be used to set the starting line for
searches if the second address contains a regular expression. The value
of the first address in a range cannot exceed the value of the second.

   Addresses can be omitted on either side of the comma or semicolon
separator. If only the first address is given in a range, then the
second address is set to the given address. If only the second address
is given, the resulting address pairs are '1,addr' and '.;addr'
respectively. If a N-tuple of addresses is given where N > 2, then the
corresponding range is determined by the last two addresses in the
N-tuple. If only one address is expected, then the last address is
used. It is an error to give any number of addresses to a command that
requires zero addresses.

   A line address is constructed as follows:

'.'
     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,$'.

'+N'
     The Nth next line, where N is a non-negative number.

'-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.

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

','
     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.

'?RE?'
     The previous line containing the regular expression RE. The search
     wraps to the end of the buffer and continues up to the current
     line, if necessary.

''x'
     The apostrophe-x character pair addresses the line previously
     marked by a 'k' (mark) command, where 'x' is a lower case letter
     from the portable character set '[a-z]'.


   Addresses can be followed by one or more address offsets, optionally
separated by whitespace. Offsets are constructed as follows:

   * '+' or '-' followed by a number adds or subtracts the indicated
     number of lines to or from the address.

   * '+' or '-' not followed by a number adds or subtracts 1 to or from
     the address.

   * A number adds the indicated number of lines to the address.


   It is not an error if an intermediate address value is negative or
greater than the address of the last line in the buffer. It is an error
if the final address value is negative or greater than the address of
the last line in the buffer. It is an error if a search for a RE fails
to find a matching line.


File: ed.info,  Node: Regular expressions,  Next: Commands,  Prev: Line addressing,  Up: Top

5 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 text.

   In addition to specifying string literals, regular expressions can
represent classes of strings. Strings thus represented are said to be
matched by the corresponding regular expression. If it is possible for a
regular expression to match several strings in a line, then the
left-most match is the one selected. If the regular expression permits a
variable number of matching characters, the longest sequence starting at
that point is matched.

   A null RE is equivalent to the last RE encountered.

   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, other than '{', '}', '(', ')',
     '<', '>', 'b', 'B', 'w', 'W', '+' 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 characters. 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 CHAR-CLASS, then
     it matches itself. All other characters in CHAR-CLASS match
     themselves.

     Patterns in CHAR-CLASS of the form:
          [.COL-ELM.]
          [=COL-ELM=]

     where COL-ELM is a "collating element" are interpreted according
     to 'locale (5)'. See 'regex (7)' 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 expression, then it
     anchors the regular expression to the beginning of a line.
     Otherwise, it matches itself.

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

'\(RE\)'
     Defines a (possibly null) 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
     subexpression. For example, the regular expression '\(a.c\)\1'
     matches the string 'abcabc', but not 'abcadc'. Subexpressions are
     ordered relative to their left delimiter.

'*'
     Matches zero or more repetitions of the regular expression
     immediately preceding it. The regular expression can be either a
     single character regular expression or a subexpression. 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.

'\{N,M\}'
'\{N,\}'
'\{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. If any of these forms
     occurs first in a regular expression or subexpression, then it is
     interpreted literally (i.e., the regular expression '\{2\}'
     matches the string '{2}', and so on).

'\<'
'\>'
     Anchors the single character regular expression or subexpression
     immediately following it to the beginning (in the case of '\<') or
     ending (in the case of '\>') of a "word", i.e., in ASCII, a
     maximal string of alphanumeric characters, including the
     underscore (_).


   The following extended regular expression operators are preceded by a
backslash '\' to distinguish them from traditional 'ed' syntax.  They
may be unavailable depending on the particular regex implementation in
your system.

'\`'
'\''
     Unconditionally matches the beginning '\`' or ending '\'' of a
     line.

'\?'
     Optionally matches the single character regular expression or
     subexpression immediately preceding it. For example, the regular
     expression 'a[bd]\?c' matches the strings 'abc', 'adc' and 'ac'.
     If '\?' occurs at the beginning of a regular expressions or
     subexpression, then it matches a literal '?'.

'\+'
     Matches the single character regular expression or subexpression
     immediately preceding it one or more times. So the regular
     expression 'a\+' is shorthand for 'aa*'. If '\+' occurs at the
     beginning of a regular expression or subexpression, then it
     matches a literal '+'.

'\b'
     Matches the beginning or ending (null string) of a word. Thus the
     regular expression '\bhello\b' is equivalent to '\<hello\>'.
     However, '\b\b' is a valid regular expression whereas '\<\>' is
     not.

'\B'
     Matches (a null string) inside a word.

'\w'
     Matches any character in a word.

'\W'
     Matches any character not in a word.



File: ed.info,  Node: Commands,  Next: Limitations,  Prev: Regular expressions,  Up: Top

6 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. However, 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. It is not portable to give more than one print suffix, but
'ed' allows any combination of non-repeated print suffixes and combines
their effects. If any suffix letter is given, it must immediately
follow the command.

   The 'e', 'E', 'f', 'r', and 'w' commands take an optional FILE
parameter, separated from the command letter by one or more whitespace
characters.

   An interrupt (typically <Control-C>) has the effect of aborting the
current command and returning the editor to command mode.

   'ed' recognizes the following commands. The commands are shown
together with the default address or address range supplied if none is
specified (in parenthesis).

'(.)a'
     Appends text to the buffer after the addressed line. The address
     '0' (zero) is valid for this command; it places the entered text at
     the beginning of the buffer. Text is entered in input mode. The
     current address is set to the address of the last line entered or,
     if there were none, to the addressed line.

'(.,.)c'
     Changes lines in the buffer. The addressed lines are deleted from
     the buffer, and text is inserted in their place. Text is entered
     in input mode.  The current address is set to the address of the
     last line entered or, if there were none, to the new address of
     the line after the last line deleted; if the lines deleted were
     originally at the end of the buffer, the current address is set to
     the address of the new last line; if no lines remain in the
     buffer, the current address is set to zero. The lines deleted are
     copied to the cut buffer.

'(.,.)d'
     Deletes the addressed lines from the buffer. The current address
     is set to the new address of the line after the last line deleted;
     if the lines deleted were originally at the end of the buffer, the
     current address is set to the address of the new last line; if no
     lines remain in the buffer, the current address is set to zero.
     The lines deleted are copied to the cut buffer.

'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 before the new file is read. The current
     address is set to the address of the last line in the buffer.

     If FILE is prefixed with a bang (!), then it is interpreted as a
     shell command whose output is to be read, (*note shell escape
     command:: '!' below). In this case the default filename is
     unchanged.

     A warning is printed if any changes have been made in the buffer
     since the last 'w' command that wrote the entire buffer to a file.

'E FILE'
     Edits FILE unconditionally. This is similar to the 'e' command,
     except that unwritten changes are discarded without warning.

'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'
     Global command. The global command makes two passes over the file.
     On the first pass, all the addressed lines matching a regular
     expression RE are marked. Then, going sequentially from the
     beginning of the file to the end of the file, the given
     COMMAND-LIST is executed for each marked line, with the current
     address set to the address of that line. Any line modified by the
     COMMAND-LIST is unmarked. The final value of the current address
     is the value assigned by the last command in the last COMMAND-LIST
     executed. If there were no matching lines, the current address is
     unchanged.

     The first command of COMMAND-LIST must appear on the same line as
     the 'g' command. The other commands of COMMAND-LIST must appear on
     separate lines. All lines of a multi-line COMMAND-LIST except the
     last line must be terminated with a backslash ('\'). Any commands
     are allowed, except for 'g', 'G', 'v', and 'V'. The '.'
     terminating the input mode of commands 'a', 'c', and 'i' can be
     omitted if it would be the last line of COMMAND-LIST. By default, a
     newline alone in COMMAND-LIST is equivalent to a 'p' command. If
     'ed' is invoked with the command-line option '-G', then a newline
     in COMMAND-LIST is equivalent to a '.+1p' command.

'(1,$)G/RE/'
     Interactive global command. 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. The final value of the current address is
     the value assigned by the last command executed. If there were no
     matching lines, the current address is unchanged.

     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'
     Help. Prints an explanation of the last error.

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

'(.)i'
     Inserts text in the buffer before the addressed line. The address
     '0' (zero) is valid for this command; it places the entered text at
     the beginning of the buffer. Text is entered in input mode. The
     current address is set to the address of the last line entered or,
     if there were none, to the addressed line.

'(.,.+1)j'
     Joins the addressed lines, replacing them by a single line
     containing their joined text. If only one address is given, this
     command does nothing. If lines are joined, the lines replaced are
     copied to the cut buffer and the current address is set to the
     address of the joined line. Else, the current address is unchanged.

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

'(.,.)l'
     List command. Prints the addressed lines unambiguously. The end of
     each line is marked with a '$', and every '$' character within the
     text is printed with a preceding backslash. Special characters are
     printed as escape sequences. The current address is set to the
     address of the last line printed.

'(.,.)m(.)'
     Moves lines in the buffer. The addressed lines are moved to after
     the right-hand destination address. The destination address '0'
     (zero) is valid for this command; it moves the addressed lines to
     the beginning of the buffer. It is an error if the destination
     address falls within the range of lines to be moved. The current
     address is set to the new address of the last line moved.

'(.,.)n'
     Number command. Prints the addressed lines, preceding each line by
     its line number and a <tab>. The current address is set to the
     address of the last line printed.

'(.,.)p'
     Prints the addressed lines. The current address is set to the
     address of the last line printed.

'P'
     Toggles the command prompt on and off. Unless a prompt string is
     specified with the command-line option '-p', the command prompt is
     by default turned off. The default prompt string is an asterisk
     ('*').

'q'
     Quits 'ed'. A warning is printed if any changes have been made in
     the buffer since the last 'w' command that wrote the entire buffer
     to a file.

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

'($)r FILE'
     Reads FILE and appends it after the addressed line. If FILE is not
     specified, then the default filename is used. If there is no
     default filename prior to the command, then the default filename
     is set to FILE. Otherwise, the default filename is unchanged. The
     address '0' (zero) is valid for this command; it reads the file at
     the beginning of the buffer. The current address is set to the
     address of the last line read or, if there were none, to the
     addressed line.

     If FILE is prefixed with a bang (!), then it is interpreted as a
     shell command whose output is to be read, (*note shell escape
     command:: '!' below). In this case the default filename is
     unchanged.

'(.,.)s/RE/REPLACEMENT/'
     Substitute command. Replaces text in the addressed lines matching
     a regular expression RE with REPLACEMENT. By default, only the
     first match in each line is replaced. The 's' command accepts any
     combination of the suffixes 'g', 'COUNT', 'l', 'n', and 'p'.  If
     the 'g' (global) suffix is given, then every match is replaced. The
     'COUNT' suffix, where COUNT is a positive number, causes only the
     COUNTth match to be replaced. 'g' and 'COUNT' can't be specified
     in the same command. 'l', 'n', and 'p' are the usual print
     suffixes. It is an error if no substitutions are performed on any
     of the addressed lines. The current address is set to the address
     of the last line on which a substitution occurred. If a line is
     split, a substitution is considered to have occurred on each of
     the new lines. If no substitution is performed, the current
     address is unchanged. The last line modified is copied to the cut
     buffer.

     RE and REPLACEMENT may be delimited by any character other than
     <space>, <newline> and the characters used by the form of the 's'
     command shown below. If the last delimiter is omitted, then the
     last line affected is printed as if the print suffix 'p' were
     specified. The last delimiter can't be omitted if the 's' command
     is part of a 'g' or 'v' COMMAND-LIST and is not the last command
     in the list, because the meaning of the following escaped newline
     would become ambiguous.

     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 the corresponding backreference expression
     does not match, then the character sequence '\M' is replaced by
     the empty string. If REPLACEMENT consists of a single '%', then
     REPLACEMENT from the last substitution is used.

     A line can be split by including a newline escaped with a backslash
     ('\') in REPLACEMENT. Each backslash in REPLACEMENT removes the
     special meaning (if any) of the following character.

'(.,.)s'
     Repeats the last substitution. This form of the 's' command accepts
     the 'g' and 'COUNT' suffixes described above, and any combination
     of the suffixes 'p' and 'r'. The 'g' suffix toggles the global
     suffix of the last substitution and resets COUNT to 1. The 'p'
     suffix toggles the print suffixes of the last substitution. The
     'r' suffix causes the RE of the last search to be used instead of
     the RE of the last substitution (if the search happened after the
     substitution).

'(.,.)t(.)'
     Copies (i.e., transfers) the addressed lines to after the
     right-hand destination address. If the destination address is '0'
     (zero), the lines are copied at the beginning of the buffer. The
     current address is set to the address of the last line copied.

'u'
     Undoes the effect of the last command that modified anything in
     the buffer and restores the current address to what it was before
     the command. The global commands 'g', 'G', 'v', and 'V' are
     treated as a single command by undo. 'u' is its own inverse; it
     can undo only the last command.

'(1,$)v/RE/COMMAND-LIST'
     This is similar to the 'g' command except that it applies
     COMMAND-LIST to each of the addressed lines not matching the
     regular expression RE.

'(1,$)V/RE/'
     This is similar to the 'G' command except that it interactively
     edits the addressed lines not matching the regular expression RE.

'(1,$)w FILE'
     Writes the addressed lines to FILE. Any previous contents of FILE
     are 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.

     If FILE is prefixed with a bang (!), then it is interpreted as a
     shell command and the addressed lines are written to its standard
     input, (*note shell escape command:: '!' below). In this case the
     default filename is unchanged. Writing the buffer to a shell
     command does not prevent the warning to the user if an attempt is
     made to overwrite or discard the buffer via the 'e' or 'q'
     commands.

'(1,$)wq FILE'
     Writes the addressed lines to FILE, and then executes a 'q'
     command.

'(1,$)W FILE'
     Appends the addressed lines to the end of FILE. This is similar to
     the 'w' command, except that the previous contents of FILE are not
     clobbered. The current address is unchanged.

'(.)x'
     Copies (puts) the contents of the cut buffer to after the addressed
     line. The current address is set to the address of the last line
     copied.

'(.,.)y'
     Copies (yanks) the addressed lines to the cut buffer. The cut
     buffer is overwritten by subsequent 'c', 'd', 'j', 's', or 'y'
     commands. The current address is unchanged.

'(.+1)zN'
     Scroll. Prints N lines at a time starting at addressed line, and
     sets window size to N. If N is not specified, then the current
     window size is used. Window size defaults to screen size minus two
     lines, or to 22 if screen size can't be determined. The current
     address is set to the address of the last line printed.

'!COMMAND'
     Shell escape command. Executes COMMAND via 'sh (1)'. If the first
     character of COMMAND is '!', then it is replaced by the text of
     the previous '!COMMAND'. Thus, '!!' repeats the previous
     '!COMMAND'. 'ed' does not process 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 address is unchanged.

'(.,.)#'
     Begins a comment; the rest of the line, up to a newline, is
     ignored. If a line address followed by a semicolon is given, then
     the current address is set to that address. Otherwise, the current
     address is unchanged.

'($)='
     Prints the line number of the addressed line. The current address
     is unchanged.

'(.+1)<newline>'
     Null command. An address alone prints the addressed line. A
     <newline> alone is equivalent to '+1p'. The current address is set
     to the address of the printed line.



File: ed.info,  Node: Limitations,  Next: Diagnostics,  Prev: Commands,  Up: Top

7 Limitations
*************

If the terminal hangs up, 'ed' attempts to write the buffer to the file
'ed.hup' or, if this fails, to '$HOME/ed.hup'.

   'ed' processes FILE arguments for backslash escapes, i.e., in a
filename, any character preceded by a backslash ('\') is interpreted
literally. For example, 'ed 'hello\tworld'' will edit the file
'hellotworld'.

   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 reading/writing. A
binary file is one containing at least one ASCII NUL character. If the
last line has been modified, reading an empty file, for example
/dev/null, prior to writing prevents appending a newline to a binary
file.

   In order to keep track of the text lines in the buffer, 'ed' uses a
doubly linked list of structures containing the position and size of
each line. This results in a per line overhead of 2 'pointer's, 1 'long
int', and 1 'int'.


File: ed.info,  Node: Diagnostics,  Next: Problems,  Prev: Limitations,  Up: Top

8 Diagnostics
*************

When an error occurs, if 'ed''s input is from a regular file or here
document, then it exits, otherwise it prints a '?' and returns to
command mode. An explanation of the last error can be printed with the
'h' (help) command.

   If the 'u' (undo) command occurs in a global command list, then the
command list is executed only once.

   Attempting to quit 'ed' 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.


File: ed.info,  Node: Problems,  Next: GNU Free Documentation License,  Prev: Diagnostics,  Up: Top

9 Reporting bugs
****************

There are probably bugs in 'ed'. There are certainly errors and
omissions in this manual. If you report them, they will get fixed. If
you don't, no one will ever know about them and they will remain unfixed
for all eternity, if not longer.

   If you find a bug in 'ed', please send electronic mail to
<bug-ed@gnu.org>. Include the version number, which you can find by
running 'ed --version'.


File: ed.info,  Node: GNU Free Documentation License,  Prev: Problems,  Up: Top

10 GNU Free Documentation License
*********************************

                     Version 1.3, 3 November 2008

     Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     'http://fsf.org/'

     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

  0. PREAMBLE

     The purpose of this License is to make a manual, textbook, or other
     functional and useful document "free" in the sense of freedom: to
     assure everyone the effective freedom to copy and redistribute it,
     with or without modifying it, either commercially or
     noncommercially.  Secondarily, this License preserves for the
     author and publisher a way to get credit for their work, while not
     being considered responsible for modifications made by others.

     This License is a kind of "copyleft", which means that derivative
     works of the document must themselves be free in the same sense.
     It complements the GNU General Public License, which is a copyleft
     license designed for free software.

     We have designed this License in order to use it for manuals for
     free software, because free software needs free documentation: a
     free program should come with manuals providing the same freedoms
     that the software does.  But this License is not limited to
     software manuals; it can be used for any textual work, regardless
     of subject matter or whether it is published as a printed book.
     We recommend this License principally for works whose purpose is
     instruction or reference.

  1. APPLICABILITY AND DEFINITIONS

     This License applies to any manual or other work, in any medium,
     that contains a notice placed by the copyright holder saying it
     can be distributed under the terms of this License.  Such a notice
     grants a world-wide, royalty-free license, unlimited in duration,
     to use that work under the conditions stated herein.  The
     "Document", below, refers to any such manual or work.  Any member
     of the public is a licensee, and is addressed as "you".  You
     accept the license if you copy, modify or distribute the work in a
     way requiring permission under copyright law.

     A "Modified Version" of the Document means any work containing the
     Document or a portion of it, either copied verbatim, or with
     modifications and/or translated into another language.

     A "Secondary Section" is a named appendix or a front-matter section
     of the Document that deals exclusively with the relationship of the
     publishers or authors of the Document to the Document's overall
     subject (or to related matters) and contains nothing that could
     fall directly within that overall subject.  (Thus, if the Document
     is in part a textbook of mathematics, a Secondary Section may not
     explain any mathematics.)  The relationship could be a matter of
     historical connection with the subject or with related matters, or
     of legal, commercial, philosophical, ethical or political position
     regarding them.

     The "Invariant Sections" are certain Secondary Sections whose
     titles are designated, as being those of Invariant Sections, in
     the notice that says that the Document is released under this
     License.  If a section does not fit the above definition of
     Secondary then it is not allowed to be designated as Invariant.
     The Document may contain zero Invariant Sections.  If the Document
     does not identify any Invariant Sections then there are none.

     The "Cover Texts" are certain short passages of text that are
     listed, as Front-Cover Texts or Back-Cover Texts, in the notice
     that says that the Document is released under this License.  A
     Front-Cover Text may be at most 5 words, and a Back-Cover Text may
     be at most 25 words.

     A "Transparent" copy of the Document means a machine-readable copy,
     represented in a format whose specification is available to the
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     straightforwardly with generic text editors or (for images
     composed of pixels) generic paint programs or (for drawings) some
     widely available drawing editor, and that is suitable for input to
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     formats suitable for input to text formatters.  A copy made in an
     otherwise Transparent file format whose markup, or absence of
     markup, has been arranged to thwart or discourage subsequent
     modification by readers is not Transparent.  An image format is
     not Transparent if used for any substantial amount of text.  A
     copy that is not "Transparent" is called "Opaque".

     Examples of suitable formats for Transparent copies include plain
     ASCII without markup, Texinfo input format, LaTeX input format,
     SGML or XML using a publicly available DTD, and
     standard-conforming simple HTML, PostScript or PDF designed for
     human modification.  Examples of transparent image formats include
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     can be read and edited only by proprietary word processors, SGML or
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     available, and the machine-generated HTML, PostScript or PDF
     produced by some word processors for output purposes only.

     The "Title Page" means, for a printed book, the title page itself,
     plus such following pages as are needed to hold, legibly, the
     material this License requires to appear in the title page.  For
     works in formats which do not have any title page as such, "Title
     Page" means the text near the most prominent appearance of the
     work's title, preceding the beginning of the body of the text.

     The "publisher" means any person or entity that distributes copies
     of the Document to the public.

     A section "Entitled XYZ" means a named subunit of the Document
     whose title either is precisely XYZ or contains XYZ in parentheses
     following text that translates XYZ in another language.  (Here XYZ
     stands for a specific section name mentioned below, such as
     "Acknowledgements", "Dedications", "Endorsements", or "History".)
     To "Preserve the Title" of such a section when you modify the
     Document means that it remains a section "Entitled XYZ" according
     to this definition.

     The Document may include Warranty Disclaimers next to the notice
     which states that this License applies to the Document.  These
     Warranty Disclaimers are considered to be included by reference in
     this License, but only as regards disclaiming warranties: any other
     implication that these Warranty Disclaimers may have is void and
     has no effect on the meaning of this License.

  2. VERBATIM COPYING

     You may copy and distribute the Document in any medium, either
     commercially or noncommercially, provided that this License, the
     copyright notices, and the license notice saying this License
     applies to the Document are reproduced in all copies, and that you
     add no other conditions whatsoever to those of this License.  You
     may not use technical measures to obstruct or control the reading
     or further copying of the copies you make or distribute.  However,
     you may accept compensation in exchange for copies.  If you
     distribute a large enough number of copies you must also follow
     the conditions in section 3.

     You may also lend copies, under the same conditions stated above,
     and you may publicly display copies.

  3. COPYING IN QUANTITY

     If you publish printed copies (or copies in media that commonly
     have printed covers) of the Document, numbering more than 100, and
     the Document's license notice requires Cover Texts, you must
     enclose the copies in covers that carry, clearly and legibly, all
     these Cover Texts: Front-Cover Texts on the front cover, and
     Back-Cover Texts on the back cover.  Both covers must also clearly
     and legibly identify you as the publisher of these copies.  The
     front cover must present the full title with all words of the
     title equally prominent and visible.  You may add other material
     on the covers in addition.  Copying with changes limited to the
     covers, as long as they preserve the title of the Document and
     satisfy these conditions, can be treated as verbatim copying in
     other respects.

     If the required texts for either cover are too voluminous to fit
     legibly, you should put the first ones listed (as many as fit
     reasonably) on the actual cover, and continue the rest onto
     adjacent pages.

     If you publish or distribute Opaque copies of the Document
     numbering more than 100, you must either include a
     machine-readable Transparent copy along with each Opaque copy, or
     state in or with each Opaque copy a computer-network location from
     which the general network-using public has access to download
     using public-standard network protocols a complete Transparent
     copy of the Document, free of added material.  If you use the
     latter option, you must take reasonably prudent steps, when you
     begin distribution of Opaque copies in quantity, to ensure that
     this Transparent copy will remain thus accessible at the stated
     location until at least one year after the last time you
     distribute an Opaque copy (directly or through your agents or
     retailers) of that edition to the public.

     It is requested, but not required, that you contact the authors of
     the Document well before redistributing any large number of
     copies, to give them a chance to provide you with an updated
     version of the Document.

  4. MODIFICATIONS

     You may copy and distribute a Modified Version of the Document
     under the conditions of sections 2 and 3 above, provided that you
     release the Modified Version under precisely this License, with
     the Modified Version filling the role of the Document, thus
     licensing distribution and modification of the Modified Version to
     whoever possesses a copy of it.  In addition, you must do these
     things in the Modified Version:

       A. Use in the Title Page (and on the covers, if any) a title
          distinct from that of the Document, and from those of
          previous versions (which should, if there were any, be listed
          in the History section of the Document).  You may use the
          same title as a previous version if the original publisher of
          that version gives permission.

       B. List on the Title Page, as authors, one or more persons or
          entities responsible for authorship of the modifications in
          the Modified Version, together with at least five of the
          principal authors of the Document (all of its principal
          authors, if it has fewer than five), unless they release you
          from this requirement.

       C. State on the Title page the name of the publisher of the
          Modified Version, as the publisher.

       D. Preserve all the copyright notices of the Document.

       E. Add an appropriate copyright notice for your modifications
          adjacent to the other copyright notices.

       F. Include, immediately after the copyright notices, a license
          notice giving the public permission to use the Modified
          Version under the terms of this License, in the form shown in
          the Addendum below.

       G. Preserve in that license notice the full lists of Invariant
          Sections and required Cover Texts given in the Document's
          license notice.

       H. Include an unaltered copy of this License.

       I. Preserve the section Entitled "History", Preserve its Title,
          and add to it an item stating at least the title, year, new
          authors, and publisher of the Modified Version as given on
          the Title Page.  If there is no section Entitled "History" in
          the Document, create one stating the title, year, authors,
          and publisher of the Document as given on its Title Page,
          then add an item describing the Modified Version as stated in
          the previous sentence.

       J. Preserve the network location, if any, given in the Document
          for public access to a Transparent copy of the Document, and
          likewise the network locations given in the Document for
          previous versions it was based on.  These may be placed in
          the "History" section.  You may omit a network location for a
          work that was published at least four years before the
          Document itself, or if the original publisher of the version
          it refers to gives permission.

       K. For any section Entitled "Acknowledgements" or "Dedications",
          Preserve the Title of the section, and preserve in the
          section all the substance and tone of each of the contributor
          acknowledgements and/or dedications given therein.

       L. Preserve all the Invariant Sections of the Document,
          unaltered in their text and in their titles.  Section numbers
          or the equivalent are not considered part of the section
          titles.

       M. Delete any section Entitled "Endorsements".  Such a section
          may not be included in the Modified Version.

       N. Do not retitle any existing section to be Entitled
          "Endorsements" or to conflict in title with any Invariant
          Section.

       O. Preserve any Warranty Disclaimers.

     If the Modified Version includes new front-matter sections or
     appendices that qualify as Secondary Sections and contain no
     material copied from the Document, you may at your option
     designate some or all of these sections as invariant.  To do this,
     add their titles to the list of Invariant Sections in the Modified
     Version's license notice.  These titles must be distinct from any
     other section titles.

     You may add a section Entitled "Endorsements", provided it contains
     nothing but endorsements of your Modified Version by various
     parties--for example, statements of peer review or that the text
     has been approved by an organization as the authoritative
     definition of a standard.

     You may add a passage of up to five words as a Front-Cover Text,
     and a passage of up to 25 words as a Back-Cover Text, to the end
     of the list of Cover Texts in the Modified Version.  Only one
     passage of Front-Cover Text and one of Back-Cover Text may be
     added by (or through arrangements made by) any one entity.  If the
     Document already includes a cover text for the same cover,
     previously added by you or by arrangement made by the same entity
     you are acting on behalf of, you may not add another; but you may
     replace the old one, on explicit permission from the previous
     publisher that added the old one.

     The author(s) and publisher(s) of the Document do not by this
     License give permission to use their names for publicity for or to
     assert or imply endorsement of any Modified Version.

  5. COMBINING DOCUMENTS

     You may combine the Document with other documents released under
     this License, under the terms defined in section 4 above for
     modified versions, provided that you include in the combination
     all of the Invariant Sections of all of the original documents,
     unmodified, and list them all as Invariant Sections of your
     combined work in its license notice, and that you preserve all
     their Warranty Disclaimers.

     The combined work need only contain one copy of this License, and
     multiple identical Invariant Sections may be replaced with a single
     copy.  If there are multiple Invariant Sections with the same name
     but different contents, make the title of each such section unique
     by adding at the end of it, in parentheses, the name of the
     original author or publisher of that section if known, or else a
     unique number.  Make the same adjustment to the section titles in
     the list of Invariant Sections in the license notice of the
     combined work.

     In the combination, you must combine any sections Entitled
     "History" in the various original documents, forming one section
     Entitled "History"; likewise combine any sections Entitled
     "Acknowledgements", and any sections Entitled "Dedications".  You
     must delete all sections Entitled "Endorsements."

  6. COLLECTIONS OF DOCUMENTS

     You may make a collection consisting of the Document and other
     documents released under this License, and replace the individual
     copies of this License in the various documents with a single copy
     that is included in the collection, provided that you follow the
     rules of this License for verbatim copying of each of the
     documents in all other respects.

     You may extract a single document from such a collection, and
     distribute it individually under this License, provided you insert
     a copy of this License into the extracted document, and follow
     this License in all other respects regarding verbatim copying of
     that document.

  7. AGGREGATION WITH INDEPENDENT WORKS

     A compilation of the Document or its derivatives with other
     separate and independent documents or works, in or on a volume of
     a storage or distribution medium, is called an "aggregate" if the
     copyright resulting from the compilation is not used to limit the
     legal rights of the compilation's users beyond what the individual
     works permit.  When the Document is included in an aggregate, this
     License does not apply to the other works in the aggregate which
     are not themselves derivative works of the Document.

     If the Cover Text requirement of section 3 is applicable to these
     copies of the Document, then if the Document is less than one half
     of the entire aggregate, the Document's Cover Texts may be placed
     on covers that bracket the Document within the aggregate, or the
     electronic equivalent of covers if the Document is in electronic
     form.  Otherwise they must appear on printed covers that bracket
     the whole aggregate.

  8. TRANSLATION

     Translation is considered a kind of modification, so you may
     distribute translations of the Document under the terms of section
     4.  Replacing Invariant Sections with translations requires special
     permission from their copyright holders, but you may include
     translations of some or all Invariant Sections in addition to the
     original versions of these Invariant Sections.  You may include a
     translation of this License, and all the license notices in the
     Document, and any Warranty Disclaimers, provided that you also
     include the original English version of this License and the
     original versions of those notices and disclaimers.  In case of a
     disagreement between the translation and the original version of
     this License or a notice or disclaimer, the original version will
     prevail.

     If a section in the Document is Entitled "Acknowledgements",
     "Dedications", or "History", the requirement (section 4) to
     Preserve its Title (section 1) will typically require changing the
     actual title.

  9. TERMINATION

     You may not copy, modify, sublicense, or distribute the Document
     except as expressly provided under this License.  Any attempt
     otherwise to copy, modify, sublicense, or distribute it is void,
     and will automatically terminate your rights under this License.

     However, if you cease all violation of this License, then your
     license from a particular copyright holder is reinstated (a)
     provisionally, unless and until the copyright holder explicitly
     and finally terminates your license, and (b) permanently, if the
     copyright holder fails to notify you of the violation by some
     reasonable means prior to 60 days after the cessation.

     Moreover, your license from a particular copyright holder is
     reinstated permanently if the copyright holder notifies you of the
     violation by some reasonable means, this is the first time you have
     received notice of violation of this License (for any work) from
     that copyright holder, and you cure the violation prior to 30 days
     after your receipt of the notice.

     Termination of your rights under this section does not terminate
     the licenses of parties who have received copies or rights from
     you under this License.  If your rights have been terminated and
     not permanently reinstated, receipt of a copy of some or all of
     the same material does not give you any rights to use it.

 10. FUTURE REVISIONS OF THIS LICENSE

     The Free Software Foundation may publish new, revised versions of
     the GNU Free Documentation License from time to time.  Such new
     versions will be similar in spirit to the present version, but may
     differ in detail to address new problems or concerns.  See
     'http://www.gnu.org/copyleft/'.

     Each version of the License is given a distinguishing version
     number.  If the Document specifies that a particular numbered
     version of this License "or any later version" applies to it, you
     have the option of following the terms and conditions either of
     that specified version or of any later version that has been
     published (not as a draft) by the Free Software Foundation.  If
     the Document does not specify a version number of this License,
     you may choose any version ever published (not as a draft) by the
     Free Software Foundation.  If the Document specifies that a proxy
     can decide which future versions of this License can be used, that
     proxy's public statement of acceptance of a version permanently
     authorizes you to choose that version for the Document.

 11. RELICENSING

     "Massive Multiauthor Collaboration Site" (or "MMC Site") means any
     World Wide Web server that publishes copyrightable works and also
     provides prominent facilities for anybody to edit those works.  A
     public wiki that anybody can edit is an example of such a server.
     A "Massive Multiauthor Collaboration" (or "MMC") contained in the
     site means any set of copyrightable works thus published on the MMC
     site.

     "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
     license published by Creative Commons Corporation, a not-for-profit
     corporation with a principal place of business in San Francisco,
     California, as well as future copyleft versions of that license
     published by that same organization.

     "Incorporate" means to publish or republish a Document, in whole or
     in part, as part of another Document.

     An MMC is "eligible for relicensing" if it is licensed under this
     License, and if all works that were first published under this
     License somewhere other than this MMC, and subsequently
     incorporated in whole or in part into the MMC, (1) had no cover
     texts or invariant sections, and (2) were thus incorporated prior
     to November 1, 2008.

     The operator of an MMC Site may republish an MMC contained in the
     site under CC-BY-SA on the same site at any time before August 1,
     2009, provided the MMC is eligible for relicensing.


ADDENDUM: How to use this License for your documents
====================================================

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and license
notices just after the title page:

       Copyright (C)  YEAR  YOUR NAME.
       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version 1.3
       or any later version published by the Free Software Foundation;
       with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
       Texts.  A copy of the license is included in the section entitled ``GNU
       Free Documentation License''.

   If you have Invariant Sections, Front-Cover Texts and Back-Cover
Texts, replace the "with...Texts." line with this:

         with the Invariant Sections being LIST THEIR TITLES, with
         the Front-Cover Texts being LIST, and with the Back-Cover Texts
         being LIST.

   If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.

   If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License, to
permit their use in free software.



Tag Table:
Node: Top535
Node: Overview1710
Node: Introduction to line editing4175
Node: Invoking ed11448
Node: Line addressing13565
Node: Regular expressions17267
Node: Commands22974
Ref: shell escape command37385
Node: Limitations38407
Node: Diagnostics39499
Node: Problems40144
Node: GNU Free Documentation License40677

End Tag Table


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