glenda.party
term% ls -F
term% pwd
$home/manuals/plan9_4th/1/ed
term% cat index.txt
ED(1)                       General Commands Manual                      ED(1)



NAME
       ed - text editor

SYNOPSIS
       ed [ - ] [ -o ] [ file ]

DESCRIPTION
       Ed is a venerable text editor.

       If  a  file  argument  is given, ed simulates an command (see below) on
       that file: it is read into ed's buffer so that it can be  edited.   The
       options are

       -      Suppress the printing of character counts by and commands and of
              the confirming by commands.

       -o     (for output piping) Write all output to the standard error  file
              except writing by commands.  If no file is given, make /fd/1 the
              remembered file; see the command below.

       Ed operates on a `buffer', a copy of the file it  is  editing;  changes
       made  in  the buffer have no effect on the file until a (write) command
       is given.  The copy of the text being edited  resides  in  a  temporary
       file called the buffer.

       Commands  to  ed have a simple and regular structure: zero, one, or two
       addresses followed by a single character command, possibly followed  by
       parameters  to  the command.  These addresses specify one or more lines
       in the buffer.  Missing addresses are supplied by default.

       In general, only one command may appear on a  line.   Certain  commands
       allow  the addition of text to the buffer.  While ed is accepting text,
       it is said to be in input mode.  In this mode, no commands  are  recog‐
       nized;  all  input is merely collected.  Input mode is left by typing a
       period alone at the beginning of a line.

       Ed supports the regular expression  notation  described  in  regexp(6).
       Regular  expressions  are used in addresses to specify lines and in one
       command (see s below) to specify a portion of a line which is to be re‐
       placed.   If  it  is  desired  to  use  one  of  the regular expression
       metacharacters as an ordinary character, that character may be preceded
       by  `\'.   This  also applies to the character bounding the regular ex‐
       pression (often and to itself.

       To understand addressing in ed it is necessary to know that at any time
       there  is a current line.  Generally, the current line is the last line
       affected by a command; however, the exact effect on the current line is
       discussed  under  the  description of each command.  Addresses are con‐
       structed as follows.

       1.     The character customarily called `dot',  addresses  the  current
              line.

       2.     The character addresses the last line of the buffer.

       3.     A decimal number n addresses the n-th line of the buffer.

       4.     'x  addresses  the  line marked with the name x, which must be a
              lower-case letter.  Lines are marked with the command.

       5.     A regular expression enclosed in slashes (  addresses  the  line
              found by searching forward from the current line and stopping at
              the first line containing a string that matches the regular  ex‐
              pression.  If necessary the search wraps around to the beginning
              of the buffer.

       6.     A regular expression enclosed  in  queries  addresses  the  line
              found  by  searching backward from the current line and stopping
              at the first line containing a string that matches  the  regular
              expression.   If necessary the search wraps around to the end of
              the buffer.

       7.     An address followed by a plus sign or a minus sign followed by a
              decimal number specifies that address plus (resp. minus) the in‐
              dicated number of lines.  The plus sign may be omitted.

       8.     An address followed by (or followed by a regular expression  en‐
              closed  in  slashes  specifies the first matching line following
              (or preceding) that address.  The search wraps around if  neces‐
              sary.   The  may  be omitted, so addresses the first line in the
              buffer with an Enclosing the regular expression in reverses  the
              search direction.

       9.     If  an  address  begins  with  or the addition or subtraction is
              taken with respect to the current line; e.g.  is  understood  to
              mean

       10.    If  an  address ends with or then 1 is added (resp. subtracted).
              As a consequence of this rule and rule 9, the address refers  to
              the  line before the current line.  Moreover, trailing and char‐
              acters have cumulative effect, so refers  to  the  current  line
              less 2.

       11.    To  maintain  compatibility with earlier versions of the editor,
              the character in addresses is equivalent to

       Commands may require zero, one, or two addresses.  Commands  which  re‐
       quire no addresses regard the presence of an address as an error.  Com‐
       mands which accept one or two addresses assume default  addresses  when
       insufficient are given.  If more addresses are given than a command re‐
       quires, the last one or two (depending on what is accepted) are used.

       Addresses are separated from each other typically by a comma  They  may
       also  be  separated by a semicolon In this case the current line is set
       to the previous address before the next address is interpreted.  If  no
       address precedes a comma or semicolon, line 1 is assumed; if no address
       follows, the last line of the buffer is assumed.  The second address of
       any  two-address  sequence must correspond to a line following the line
       corresponding to the first address.

       In the following list of ed commands, the default addresses  are  shown
       in  parentheses.   The parentheses are not part of the address, but are
       used to show that the given addresses are the default.  `Dot' means the
       current line.

       (.)a
       <text>
       .      Read the given text and append it after the addressed line.  Dot
              is left on the last line input, if there were any, otherwise  at
              the  addressed line.  Address is legal for this command; text is
              placed at the beginning of the buffer.

       (.,.)b[+-][pagesize][pln]
              Browse.  Print a `page', normally 20 lines.  The  optional  (de‐
              fault)  or  specifies whether the next or previous page is to be
              printed.  The optional pagesize is the  number  of  lines  in  a
              page.   The optional or causes printing in the specified format,
              initially Pagesize and format are remembered  between  commands.
              Dot is left at the last line displayed.

       (.,.)c
       <text>
       .      Change.   Delete  the addressed lines, then accept input text to
              replace these lines.  Dot is left at the  last  line  input;  if
              there  were  none,  it is left at the line preceding the deleted
              lines.

       (.,.)d Delete the addressed lines from the buffer.  Dot is set  to  the
              line following the last line deleted, or to the last line of the
              buffer if the deleted lines had no successor.

       e filename
              Edit.  Delete the entire contents of the buffer; then  read  the
              named  file into the buffer.  Dot is set to the last line of the
              buffer.  The number of characters read is typed.  The file  name
              is  remembered  for possible use in later or commands.  If file‐
              name is missing, the remembered name is used.

       E filename
              Unconditional see below.

       f filename
              Print the currently remembered file name.  If filename is given,
              the currently remembered file name is first changed to filename.

       (1,$)g/regular expression/command list
       (1,$)g/regular expression/
       (1,$)g/regular expression
              Global.   First mark every line which matches the given regular‐
              expression.  Then for every such line, execute the command  list
              with  dot  initially  set to that line.  A single command or the
              first of multiple commands appears on the  same  line  with  the
              global  command.  All lines of a multi-line list except the last
              line must end with The `.' terminating input mode for an command
              may  be  omitted  if it would be on the last line of the command
              list.  The commands and are not permitted in the  command  list.
              Any character other than space or newline may be used instead of
              to delimit the regular expression.  The second and  third  forms
              mean g/regular expression/p.

       (.)i
       <text>
       .      Insert the given text before the addressed line.  Dot is left at
              the last line input, or, if there were none, at the line  before
              the  addressed  line.   This  command differs from the a command
              only in the placement of the text.

       (.,.+1)j
              Join the addressed lines into a single line;  intermediate  new‐
              lines are deleted.  Dot is left at the resulting line.

       (.)kx  Mark  the addressed line with name x, which must be a lower-case
              letter.  The address form 'x then addresses this line.

       (.,.)l List.  Print the addressed lines in an unambiguous way: a tab is
              printed  as a backspace as backslashes as and non-printing char‐
              acters as a backslash, an and  four  hexadecimal  digits.   Long
              lines  are  folded, with the second and subsequent sub-lines in‐
              dented one tab stop.  If the last character in  the  line  is  a
              blank, it is followed by An may be appended, like to any non-I/O
              command.

       (.,.)ma
              Move.  Reposition the addressed lines after the  line  addressed
              by a.  Dot is left at the last moved line.

       (.,.)n Number.   Perform prefixing each line with its line number and a
              tab.  An may be appended, like to any non-I/O command.

       (.,.)p Print the addressed  lines.   Dot  is  left  at  the  last  line
              printed.  A appended to any non-I/O command causes the then cur‐
              rent line to be printed after the command is executed.

       (.,.)P This command is a synonym for

       q      Quit the editor.  No automatic write of a file is  done.   A  or
              command is considered to be in error if the buffer has been mod‐
              ified since the last or command.

       Q      Quit unconditionally.

       ($)r filename
              Read in the given file after the addressed line.  If no filename
              is  given,  the  remembered file name is used.  The file name is
              remembered if there were no remembered file  name  already.   If
              the  read  is  successful,  the  number  of  characters  read is
              printed.  Dot is left at the last line read from the file.

       (.,.)sn/regular expression/replacement/
       (.,.)sn/regular expression/replacement/g
       (.,.)sn/regular expression/replacement
              Substitute.  Search each addressed line for an occurrence of the
              specified  regular  expression.  On each line in which n matches
              are found (n defaults to 1 if missing), the nth  matched  string
              is  replaced  by  the  replacement specified.  If the global re‐
              placement indicator appears after the  command,  all  subsequent
              matches  on  the line are also replaced.  It is an error for the
              substitution to fail on  all  addressed  lines.   Any  character
              other  than  space  or newline may be used instead of to delimit
              the regular expression and the replacement.  Dot is left at  the
              last  line substituted.  The third form means sn/regular expres‐
              sion/replacement/p.  The second may be omitted if  the  replace‐
              ment is empty.

              An  ampersand  appearing  in  the replacement is replaced by the
              string matching the  regular  expression.   The  characters  \n,
              where n is a digit, are replaced by the text matched by the n-th
              regular subexpression enclosed between and When nested parenthe‐
              sized  subexpressions  are  present, n is determined by counting
              occurrences of starting from the left.

              A literal or newline may be included in a replacement by prefix‐
              ing it with

       (.,.)ta
              Transfer.   Copy the addressed lines after the line addressed by
              a.  Dot is left at the last line of the copy.

       (.,.)u Undo.  Restore the preceding contents  of  the  first  addressed
              line  (sic), which must be the last line in which a substitution
              was made (double sic).

       (1,$)v/regular expression/command list
              This command is the same as the global command except  that  the
              command  list  is  executed with dot initially set to every line
              except those matching the regular expression.

       (1,$)w filename
              Write the addressed lines to the given file.  If the  file  does
              not exist, it is created with mode 666 (readable and writable by
              everyone).  If no filename is given, the remembered  file  name,
              if  any,  is used.  The file name is remembered if there were no
              remembered file name already.  Dot is unchanged.  If  the  write
              is successful, the number of characters written is printed.

       (1,$)W filename
              Perform but append to, instead of overwriting, any existing file
              contents.

       ($)=   Print the line number of the addressed line.  Dot is unchanged.

       !shell command
              Send the remainder of the line after the to rc(1) to  be  inter‐
              preted as a command.  Dot is unchanged.

       (.+1)<newline>
              An  address without a command is taken as a command.  A terminal
              may be omitted from the address.  A blank line alone is  equiva‐
              lent to it is useful for stepping through text.

       If  an  interrupt  signal (DEL) is sent, ed prints a and returns to its
       command level.

       When reading a file, ed discards NUL characters and all characters  af‐
       ter the last newline.

FILES
       /tmp/e*
       ed.hup   work is saved here if terminal hangs up

SOURCE
       /sys/src/cmd/ed.c

SEE ALSO
       sam(1), sed(1), regexp(6)

DIAGNOSTICS
       ?name for inaccessible file; for temporary file overflow; for errors in
       commands or other overflows.



                                                                         ED(1)