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ED(1)									 ED(1)



NAME
       ed, red - text editor

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

       red [-] [-Gs] [-p string] [file]

DESCRIPTION
       ed is a line-oriented text editor.  It is used to create, display, mod-
       ify and otherwise manipulate text files.	 red is a  restricted  ed:  it
       can  only  edit files in the current directory and cannot execute shell
       commands.

       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 edi-
       tor buffer.  A typical command might look like:

	      ,s/old/new/g

       which replaces all occurences of the string old with new.

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

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

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

	      [address [,address]]command[parameters]

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


   OPTIONS
       -G      Forces backwards compatibility.	Affects the commands 'G', 'V',
	       'f', 'l', 'm', 't', and '!!'.

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


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


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


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

       A  line address is constructed from one of the bases in the list below,
       optionally followed by a numeric offset.	 The offset  may  include  any
       combination  of	digits,	 operators  (i.e., +, - and ^) and whitespace.
       Addresses are read from left to right, and their	 values	 are  computed
       relative to the current address.

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

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

       Each  address in a comma-delimited range is interpreted relative to the
       current address.	 In a semicolon-delimited range, the first address  is
       used  to set the current address, and the second address is interpreted
       relative to the first.


       The following address symbols are recognized.


       .       The current line (address) in the buffer.


       $       The last line in the buffer.


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


       -

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


       -n

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


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


       +n

       whitespace n
	       The  nth	 next line, where n is a non-negative number.  Whites-
	       pace followed by a number n is interpreted as +n.


       ,

       %       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 equiva-
	       lent to the address range .,$.


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


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


       ?lc     The line previously marked by a 'k' (mark) command, where lc is
	       a lower case letter.


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

	      g/string/

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

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

       The following symbols are used in constructing regular expressions:


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


       \c      A 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.] or,   [=col-elm=]

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

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

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

       \{n,m\}
       \{n,\}
       \{n\}   Matches	the  single character regular expression or subexpres-
	       sion 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 reg-
	       ular expression '\{2\}' matches the string '{2}', and so on).

       \<
       \>      Anchors	the  single character regular expression or subexpres-
	       sion immediately following it to the beginning (\<)  or	ending
	       (\>)  of	 a  word, i.e., in ASCII, a maximal string of alphanu-
	       meric characters, including the underscore (_).


       The following extended operators are preceded by	 a  backslash  (\)  to
       distinguish them from traditional ed syntax.

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

       \?      Optionally matches the single character regular	expression  or
	       subexpression immediately preceding it.	For example, the regu-
	       lar 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  subexpres-
	       sion  immediately preceding it one or more times.  So the regu-
	       lar 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.

   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.

       An interrupt (typically ^C) has the effect of aborting the current com-
       mand 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, which may
	       be the address 0 (zero).	 Text is entered in input  mode.   The
	       current address is set to last line entered.

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

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

       e file  Edits  file,  and  sets	the  default filename.	If file is not
	       specified, then the  default filename is used.	Any  lines  in
	       the  buffer  are deleted before the new file is read.  The cur-
	       rent address is set to the last line read.

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

       E file  Edits  file unconditionally.  This is similar to the e command,
	       except that unwritten changes are  discarded  without  warning.
	       The current address is set to the last line read.

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

       (1,$)g/re/command-list
	       Applies command-list to each of the addressed lines matching  a
	       regular	expression re.	The current address is set to the line
	       currently matched before command-list is executed.  At the  end
	       of the 'g' command, the current address is set to the last line
	       affected by command-list.

	       Each command in command-list must be on a  separate  line,  and
	       every  line  except  for the last must be terminated by a back-
	       slash (\).  Any commands are allowed, except for 'g', 'G', 'v',
	       and  'V'.   A  newline alone in command-list is equivalent to a
	       'p' command.

       (1,$)G/re/
	       Interactively edits the	addressed  lines  matching  a  regular
	       expression  re.	 For  each matching line, the line is printed,
	       the current address is set, and the user is prompted to enter a
	       command-list.   At  the	end  of	 the  'G' command, the current
	       address is set to the last line affected by (the last) command-
	       list.

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

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

       h       Prints an explanation of the last error.

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

       (.,.+1)j
	       Joins  the  addressed  lines.   The addressed lines are deleted
	       from the buffer and replaced by a single line containing	 their
	       joined text.  The current address is set to the resultant line.

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

       (.,.)l  Prints  the  addressed  lines unambiguously.  If invoked from a
	       terminal, ed pauses at the end of each page until a newline  is
	       entered.	  The current address is set to the last line printed.

       (.,.)m(.)
	       Moves lines in the buffer.  The addressed lines	are  moved  to
	       after  the  right-hand  destination  address,  which may be the
	       address 0 (zero).  The current address is set to the last  line
	       moved.

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

       (.,.)p  Prints the addressed lines.    If invoked from a	 terminal,  ed
	       pauses at the end of each page until a newline is entered.  The
	       current address is set to the last line printed.

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

       q       Quits ed.

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

       ($)r file
	       Reads  file to after the addressed line.	 If file is not speci-
	       fied, then the default filename	is  used.   If	there  was  no
	       default	filename  prior to the command, then the default file-
	       name is set  to	file.	Otherwise,  the	 default  filename  is
	       unchanged.  The current address is set to the last line read.

       ($)r !command
	       Reads to after the addressed line the standard output of '!com-
	       mand', (see the	!command  below).   The	 default  filename  is
	       unchanged.  The current address is set to the last line read.

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

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


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

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

       (.,.)t(.)
	       Copies  (i.e.,  transfers)  the	addressed  lines  to after the
	       right-hand destination address, which  may  be  the  address  0
	       (zero).	The current address is set to the last line copied.

       u       Undoes  the  last  command  and restores the current address to
	       what it was before the command.	The global commands 'g',  'G',
	       'v', and 'V'.  are treated as a single command by undo.	'u' is
	       its own inverse.

       (1,$)v/re/command-list
	       Applies command-list to each of the addressed lines not	match-
	       ing  a  regular expression re.  This is similar to the 'g' com-
	       mand.

       (1,$)V/re/
	       Interactively edits the addressed lines not matching a  regular
	       expression re.  This is similar to the 'G' command.

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

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

       (1,$)w !command
	       Writes the addressed lines to the standard input of '!command',
	       (see  the  !command  below).   The default filename and current
	       address are unchanged.

       (1,$)W file
	       Appends the addressed lines to the end of file.	This is	 simi-
	       lar  to	the  'w' command, expect that the previous contents of
	       file is 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 last line
	       copied.

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

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

       !command
	       Executes command via sh(1).  If the first character of  command
	       is '!', then it is replaced by text of the previous '!command'.
	       ed does not process command for backslash  (\)  escapes.	  How-
	       ever,  an  unescaped  '%'  is replaced by the default filename.
	       When the shell returns from execution, a '!'  is printed to the
	       standard output.	 The current line is unchanged.

       (.,.)#  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.

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

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

SEE ALSO
       vi(1), sed(1), regex(3), sh(1).

       USD:12-13

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

LIMITATIONS
       ed  processes  file  arguments for backslash escapes, i.e.,  in a file-
       name, any characters preceded by a backslash (\) are interpreted liter-
       ally.

       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.

       per line overhead: 4 ints

DIAGNOSTICS
       When an error occurs, if ed's input is from a regular file or here doc-
       ument, 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.

       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.

       ed exits with 0 if no errors occurred; otherwise >0.



			       10 November 1994				 ED(1)
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