EX(1)

NAME
ex, edit - text editor

SYNOPSIS
ex [ -c command | +command ] [ -l ] [ -L ] [ -r [filename] ] [ -R ] [ -s | - ] [ -t tagstring ] [ -v ] [ -V ] [ -w size ] [ filename ... ]

edit [ -c command | +command ] [ -l ] [ -L ] [ -r [filename] ] [ -R ] [ -s | - ] [ -t tagstring ] [ -v ] [ -V ] [ -w size ] [ filename ... ]

DESCRIPTION
Ex is the root of a family of editors: edit, ex and vi. Ex is a superset of ed, with the most notable extension being a display editing facility. Display based editing on CRT terminals is the focus of vi.

For those who have not used ed, or for casual users, the editor edit may be convenient. It avoids some of the complexities of ex used mostly by systems programmers and persons very familiar with ed.

OPTIONS

-c command or +command
    Execute command when editing begins.

-l  Start in a special mode useful for the Lisp programming language.

-r [filename] or -L
    When no argument is supplied with this option, all files to be recovered are listed and the editor exits immediately. If a filename is specified, the corresponding temporary file is opened in recovery mode.

-R  Files are opened read-only when this option is given.

-s or -
    Script mode; all feedback for interactive editing is disabled. EXINIT and .exrc files are not processed.

-t tagstring
    Read the tags file, then choose the file and position specified by tagstring for editing.

-v  Start in visual mode even if called as ex.

-V  Echo command input to standard error, unless it originates from a terminal.

-w size
    Specify the size of the editing window for visual mode.

USAGE

  File manipulation
Ex is normally editing the contents of a single file, whose name is recorded in the current file name. Ex performs all editing actions in a buffer (actually a temporary file) into which the text of the file is initially read. Changes made to the buffer have no effect on the file being edited unless and until the buffer contents are written out to the file with a write command. After the buffer contents are written, the previous contents of the written file are no longer accessible. When a file is edited, its name becomes the current file name, and its contents are read into the buffer.

The current file is almost always considered to be edited. This means that the contents of the buffer are logically connected with the current file name, so that writing the current buffer contents onto that file, even if it exists, is a reasonable action. If the current file is not edited then ex will not normally write on it if it already exists.

For saving blocks of text while editing, and especially when editing more than one file, ex has a group of named buffers. These are similar to the normal buffer, except that only a limited number of operations are available on them. The buffers have names a through z.

  Exceptional Conditions

When errors occur ex (optionally) rings the terminal bell and, in any case, prints an error diagnostic. If the primary input is from a file, editor processing will terminate. If an interrupt signal is received, ex prints “Interrupt” and returns to its command level. If the primary input is a file, then ex will exit when this occurs.

If a hangup signal is received and the buffer has been modified since it was last written out, or if the system crashes, either the editor (in the first case) or the system (after it reboots in the second) will attempt to preserve the buffer. The next time the user logs in he should be able to recover the work he was doing, losing at most a few lines of changes from the last point before the hangup or editor crash. To recover a file one can use the -r option. If one was editing the file resume, then he should change to the directory where he were when the crash occurred, giving the command

    ex -r resume

After checking that the retrieved file is indeed ok, he can write it over the previous contents of that file.

The user will normally get mail from the system telling him when a file has been saved after a crash. The command

    ex -r

will print a list of the files which have been saved for the user.

  Editing modes

Ex has five distinct modes. The primary mode is command mode. Commands are entered in command mode when a `:' prompt is present, and are executed each time a complete line is sent. In text input mode ex gathers input lines and places them in the file. The append, insert, and change commands use text input mode. No prompt is printed when in text input mode. This mode is left by typing a `.' alone at the beginning of a line, and command mode resumes.

The last three modes are open and visual modes, entered by the commands of the same name, and, within open and visual modes text insertion mode. Open and visual modes allow local editing operations to be performed on the text in the file. The open command displays one line at a time on any terminal while visual works on CRT terminals with random positioning cursors, using the screen as a (single) window for file editing changes. These modes are described (only) in An Introduction to Display Editing with Vi.

  Command structure

Most command names are English words, and initial prefixes of the words are acceptable abbreviations. The ambiguity of abbreviations is resolved in favor of the more commonly used commands.

Most commands accept prefix addresses specifying the lines in the file upon which they are to have effect. The forms of these addresses will be discussed below. A number of commands also may take a trailing count specifying the number of lines to be involved in the command. Thus the command “10p” will print the tenth line in the buffer while “delete 5” will delete five lines from the buffer, starting with the current line.

Some commands take other information or parameters, this information always being given after the command name.

A number of commands have two distinct variants. The variant form of the command is invoked by placing an `!' immediately after the command name. Some of the default variants may be controlled by options; in this case, the `!' serves to toggle the default.

The characters `#', `p' and `l' may be placed after many commands (A `p' or `l' must be preceded by a blank or tab except in the single special case `dp'). In this case, the command abbreviated by these characters is executed after the command completes. Since ex normally prints the new current line after each change, `p' is rarely necessary. Any number of `+' or `-' characters may also be given with these flags. If they appear, the specified offset is applied to the current line value before the printing command is executed.

It is possible to give editor commands which are ignored. This is useful when making complex editor scripts for which comments are desired. The comment character is the double quote: ". Any command line beginning with " is ignored. Comments beginning with " may also be placed at the ends of commands, except in cases where they could be confused as part of text (shell escapes and the substitute and map commands).

More than one command may be placed on a line by separating each pair of commands by a `|' character. However the global commands, comments, and the shell escape `!' must be the last command on a line, as they are not terminated by a `|'.

  Command addressing

.   The current line. Most commands leave the current line as the last line which they affect. The default address for most commands is the current line, thus `.' is rarely used alone as an address.

n   The nth line in the editor's buffer, lines being numbered sequentially from 1.

$   The last line in the buffer.

%   An abbreviation for “1,$”, the entire buffer.

+n -n
    An offset relative to the current buffer line. The forms `.+3' `+3' and `+++' are all equivalent; if the current line is line 100 they all address line 103.

/pat/ ?pat?
    Scan forward and backward respectively for a line containing pat, a regular expression (as defined below). The scans normally wrap around the end of the buffer. If all that is desired is to print the next line containing pat, then the trailing / or ? may be omitted. If pat is omitted or explicitly empty, then the last regular expression specified is located. The forms \/ and \? scan using the last regular expression used in a scan; after a substitute // and ?? would scan using the substitute's regular expression.

´´ ´x
    Before each non-relative motion of the current line `.', the previous current line is marked with a tag, subsequently referred to as `´´'. This makes it easy to refer or return to this previous context. Marks may also be established by the mark command, using single lower case letters x and the marked lines referred to as `´x'.

Addresses to commands consist of a series of addressing primitives, separated by `,' or `;'. Such address lists are evaluated left-to-right. When addresses are separated by `;' the current line `.' is set to the value of the previous addressing expression before the next address is interpreted. If more addresses are given than the command requires, then all but the last one or two are ignored. If the command takes two addresses, the first addressed line must precede the second in the buffer.

Null address specifications are permitted in a list of addresses, the default in this case is the current line `.'; thus `,100' is equivalent to `.,100'. It is an error to give a prefix address to a command which expects none.

  Command descriptions

The following form is a prototype for all ex commands:

    address command ! parameters count flags

All parts are optional; the degenerate case is the empty command which prints the next line in the file. For sanity with use from within visual mode, ex ignores a “:” preceding any command.

In the following command descriptions, the default addresses are shown in parentheses, which are not, however, part of the command.

abbreviate word rhs	abbr: ab
    Add the named abbreviation to the current list. When in input mode in visual, if word is typed as a complete word, it will be changed to rhs .

( . ) append    abbr: a
text
.
    Reads the input text and places it after the specified line. After the command, `.' addresses the last line input or the specified line if no lines were input. If address `0' is given, text is placed at the beginning of the buffer.

a!
text
.
    The variant flag to append toggles the setting for the autoindent option during the input of text.

args
    The members of the argument list are printed, with the current argument delimited by `[' and `]'.

cd directory
    The cd command is a synonym for chdir.

( . , . ) change count    abbr: c
text
.
    Replaces the specified lines with the input text. The current line becomes the last line input; if no lines were input it is left as for a delete.

c!
text
.
    The variant toggles autoindent during the change.

chdir directory
    The specified directory becomes the current directory. If no directory is specified, the current value of the home option is used as the target directory. After a chdir the current file is not considered to have been edited so that write restrictions on pre-existing files apply.

( . , . )copy addr flags	abbr: co
    A copy of the specified lines is placed after addr, which may be `0'. The current line `.' addresses the last line of the copy. The command t is a synonym for copy.

( . , . )delete buffer count flags	abbr: d
    Removes the specified lines from the buffer. The line after the last line deleted becomes the current line; if the lines deleted were originally at the end, the new last line becomes the current line. If a named buffer is specified by giving a letter, then the specified lines are saved in that buffer, or appended to it if an upper case letter is used.

edit file    abbr: e
ex file
    Used to begin an editing session on a new file. The editor first checks to see if the buffer has been modified since the last write command was issued. If it has been, a warning is issued and the command is aborted. The command otherwise deletes the entire contents of the editor buffer, makes the named file the current file and prints the new filename. After insuring that this file is sensible (i.e., that it is not a binary file such as a directory, a block or character special file other than /dev/tty, a terminal, or a binary or executable file), the editor reads the file into its buffer.

    If the read of the file completes without error, the number of lines and characters read is typed. Any null characters in the file are discarded. If none of these errors occurred, the file is considered edited. If the last line of the input file is missing the trailing newline character, it will be supplied and a complaint will be issued. This command leaves the current line `.' at the last line read. If executed from within open or visual, the current line is initially the first line of the file.

e! file
    The variant form suppresses the complaint about modifications having been made and not written from the editor buffer, thus discarding all changes which have been made before editing the new file.

e +n file
    Causes the editor to begin at line n rather than at the last line; n may also be an editor command containing no spaces, e.g.: “+/pat”.

file	abbr: f
    Prints the current file name, whether it has been `[Modified]' since the last write command, whether it is read only , the current line, the number of lines in the buffer, and the percentage of the way through the buffer of the current line. In the rare case that the current file is `[Not edited]' this is noted also; in this case one has to use the form w! to write to the file, since the editor is not sure that a write will not destroy a file unrelated to the current contents of the buffer.

file file
    The current file name is changed to file which is considered `[Not edited]'.

( 1 , $ ) global /pat/ cmds	abbr: g
    First marks each line among those specified which matches the given regular expression. Then the given command list is executed with `.' initially set to each marked line.

    The command list consists of the remaining commands on the current input line and may continue to multiple lines by ending all but the last such line with a `\'. If cmds (and possibly the trailing / delimiter) is omitted, each line matching pat is printed. Append, insert, and change commands and associated input are permitted; the `.' terminating input may be omitted if it would be on the last line of the command list. Open and visual commands are permitted in the command list and take input from the terminal.

    The global command itself may not appear in cmds. The undo command is also not permitted there, as undo instead can be used to reverse the entire global command. The options autoprint and autoindent are inhibited during a global, (and possibly the trailing / delimiter) and the value of the report option is temporarily infinite, in deference to a report for the entire global. Finally, the context mark `''' is set to the value of `.' before the global command begins and is not changed during a global command, except perhaps by an open or visual within the global.

g! /pat/ cmds	abbr: v
    The variant form of global runs cmds at each line not matching pat.

( . )insert    abbr: i
text
.
    Places the given text before the specified line. The current line is left at the last line input; if there were none input it is left at the line before the addressed line. This command differs from append only in the placement of text.

i!
text
.
    The variant toggles autoindent during the insert.

( . , .+1 ) join count flags	abbr: j
    Places the text from a specified range of lines together on one line. White space is adjusted at each junction to provide at least one blank character, two if there was a `.' at the end of the line, or none if the first following character is a `)'. If there is already white space at the end of the line, then the white space at the start of the next line will be discarded.

j!  The variant causes a simpler join with no white space processing; the characters in the lines are simply concatenated.

( . ) k x
    The k command is a synonym for mark. It does not require a blank or tab before the following letter.

( . , . ) list count flags
    Prints the specified lines in a more unambiguous way: tabs are printed as `^I' and the end of each line is marked with a trailing `$'. The current line is left at the last line printed.

map[!] lhs rhs
    The map command is used to define macros for use in visual command mode. Lhs should be a single character, or the sequence “#n”, for n a digit, referring to function key n. When this character or function key is typed in visual mode, it will be as though the corresponding rhs had been typed. On terminals without function keys, the user can type “#n”. If the `!' character follows the command name, the mapping is interpreted in input mode. See section 6.9 of the “Introduction to Display Editing with Vi” for more details.

( . ) mark x
    Gives the specified line mark x, a single lower case letter. The x must be preceded by a blank or a tab. The addressing form `'x' then addresses this line. The current line is not affected by this command.

( . , . ) move addr	abbr: m
    The move command repositions the specified lines to be after addr . The first of the moved lines becomes the current line.

next	abbr: n
    The next file from the command line argument list is edited.

n!  The variant suppresses warnings about the modifications to the buffer not having been written out, discarding (irretrievably) any changes which may have been made.

n filelist
n +command filelist
    The specified filelist is expanded and the resulting list replaces the current argument list; the first file in the new list is then edited. If command is given (it must contain no spaces), then it is executed after editing the first such file.

( . , . ) number count flags	abbr: # or nu
    Prints each specified line preceded by its buffer line number. The current line is left at the last line printed.

( . ) open flags    abbr: o
( . ) open /pat/ flags
    Enters intraline editing open mode at each addressed line. If pat is given, then the cursor will be placed initially at the beginning of the string matched by the pattern. To exit this mode use Q. See An Introduction to Display Editing with Vi for more details.

preserve
    The current editor buffer is saved as though the system had just crashed. This command is for use only in emergencies when a write command has resulted in an error.

( . , . )print count	abbr: p or P
    Prints the specified lines with non-printing characters printed as control characters `^x'; delete (octal 177) is represented as `^?'. The current line is left at the last line printed.

( . )put buffer	abbr: pu
    Puts back previously deleted or yanked lines. Normally used with delete to effect movement of lines, or with yank to effect duplication of lines. If no buffer is specified, then the last deleted or yanked text is restored. But no modifying commands may intervene between the delete or yank and the put, nor may lines be moved between files without using a named buffer. By using a named buffer, text may be restored that was saved there at any previous time.

quit	abbr: q
    Causes ex to terminate. No automatic write of the editor buffer to a file is performed. However, ex issues a warning message if the file has changed since the last write command was issued, and does not quit. Ex will also issue a diagnostic if there are more files in the argument list. Normally, the user will wish to save his changes, and he should give a write command; if he wishes to discard them, he should the q! command variant.

q!  Quits from the editor, discarding changes to the buffer without complaint.

( . ) read file	abbr: r
    Places a copy of the text of the given file in the editing buffer after the specified line. If no file is given the current file name is used. The current file name is not changed unless there is none in which case file becomes the current name. The sensibility restrictions for the edit command apply here also. If the file buffer is empty and there is no current name then ex treats this as an edit command.

    Address `0' is legal for this command and causes the file to be read at the beginning of the buffer. Statistics are given as for the edit command when the read successfully terminates. After a read the current line is the last line read. Within open and visual the current line is set to the first line read rather than the last.

( . ) read  !command
    Reads the output of the command command into the buffer after the specified line. This is not a variant form of the command, rather a read specifying a command rather than a filename; a blank or tab before the ! is mandatory.

recover file
    Recovers file from the system save area. Used after a accidental hangup of the phone or a system crash or preserve command. Except when preserve is used, the user will be notified by mail when a file is saved.

rewind	abbr: rew
    The argument list is rewound, and the first file in the list is edited.

rew!
    Rewinds the argument list discarding any changes made to the current buffer.

set parameter
    With no arguments, prints those options whose values have been changed from their defaults; with parameter all it prints all of the option values.

    Giving an option name followed by a `?' causes the current value of that option to be printed. The `?' is unnecessary unless the option is Boolean valued. Boolean options are given values either by the form `set option' to turn them on or `set nooption' to turn them off; string and numeric options are assigned via the form `set option=value'.

    More than one parameter may be given to set ; they are interpreted left-to-right.

    A list of options can be found below.

shell	abbr: sh
    A new shell is created. When it terminates, editing resumes.

source file	abbr: so
    Reads and executes commands from the specified file. Source commands may be nested.

( . , . ) substitute /pat/repl/ options count flags
    abbr: s
    On each specified line, the first instance of pattern pat is replaced by replacement pattern repl. If the global indicator option character `g' appears, then all instances are substituted; if the confirm indication character `c' appears, then before each substitution the line to be substituted is typed with the string to be substituted marked with `^' characters. By typing an `y' one can cause the substitution to be performed, any other input causes no change to take place. After a substitute the current line is the last line substituted.

    Lines may be split by substituting new-line characters into them. The newline in repl must be escaped by preceding it with a `\'. Other metacharacters available in pat and repl are described below.

stop
    Suspends the editor, returning control to the top level shell. If autowrite is set and there are unsaved changes, a write is done first unless the form stop ! is used. This commands is only available where supported by the teletype driver, shell and operating system.

( . , . ) substitute options count flags	abbr: s
    If pat and repl are omitted, then the last substitution is repeated. This is a synonym for the & command.

( . , . ) t addr flags
    The t command is a synonym for copy .

ta tag
    The focus of editing switches to the location of tag, switching to a different line in the current file where it is defined, or if necessary to another file.

    The tags file is normally created by a program such as ctags, and consists of a number of lines with three fields separated by blanks or tabs. The first field gives the name of the tag, the second the name of the file where the tag resides, and the third gives an addressing form which can be used by the editor to find the tag; this field is usually a contextual scan using `/pat/' to be immune to minor changes in the file. Such scans are always performed as if nomagic was set.

    The tag names in the tags file must be sorted alphabetically.

unabbreviate word	abbr: una
    Delete word from the list of abbreviations.

undo	abbr: u
    Reverses the changes made in the buffer by the last buffer editing command. Note that global commands are considered a single command for the purpose of undo (as are open and visual.) Also, the commands write and edit which interact with the file system cannot be undone. Undo is its own inverse.

    Undo always marks the previous value of the current line `.' as `'''. After an undo the current line is the first line restored or the line before the first line deleted if no lines were restored. For commands with more global effect such as global and visual the current line regains it's pre-command value after an undo.

unmap[!] lhs
    The macro expansion associated by map for lhs is removed.

( 1 , $ ) v /pat/ cmds
    A synonym for the global command variant g!, running the specified cmds on each line which does not match pat.

version	abbr: ve
    Prints the current version number of the editor as well as the date the editor was last changed.

( . ) visual type count flags	abbr: vi
    Enters visual mode at the specified line. Type is optional and may be `-' , `^' or `.' as in the z command to specify the placement of the specified line on the screen. By default, if type is omitted, the specified line is placed as the first on the screen. A count specifies an initial window size; the default is the value of the option window. See the document An Introduction to Display Editing with Vi for more details. To exit this mode, type Q.

visual file
visual +n file
    From visual mode, this command is the same as edit.

( 1 , $ ) write file	abbr: w
    Writes changes made back to file, printing the number of lines and characters written. Normally file is omitted and the text goes back where it came from. If a file is specified, then text will be written to that file. If the file does not exist it is created. The current file name is changed only if there is no current file name; the current line is never changed.

    If an error occurs while writing the current and edited file, the editor considers that there has been “No write since last change” even if the buffer had not previously been modified.

( 1 , $ ) write>> file	abbr: w>>
    Writes the buffer contents at the end of an existing file.

w! name
    Overrides the checking of the normal write command, and will write to any file which the system permits.

( 1 , $ ) w  !command
    Writes the specified lines into command. Note the difference between w! which overrides checks and w ! which writes to a command.

wq name
    Like a write and then a quit command.

wq! name
    The variant overrides checking on the sensibility of the write command, as w! does.

xit name
    If any changes have been made and not written to any file, writes the buffer out. Then, in any case, quits.

( . , . )yank buffer count	abbr: ya
    Places the specified lines in the named buffer, for later retrieval via put. If no buffer name is specified, the lines go to a more volatile place; see the put command description.

( .+1 ) z count
    Print the next count lines, default window.

( . ) z type count
    Prints a window of text with the specified line at the top. If type is `-' the line is placed at the bottom; a `.' causes the line to be placed in the center. A count gives the number of lines to be displayed rather than double the number specified by the scroll option. On a CRT the screen is cleared before display begins unless a count which is less than the screen size is given. The current line is left at the last line printed. Forms `z=' and `z^' also exist; `z=' places the current line in the center, surrounds it with lines of `-' characters and leaves the current line at this line. The form `z^' prints the window before `z-' would. The characters `+', `^' and `-' may be repeated for cumulative effect.

! command
    The remainder of the line after the `!' character is sent to a shell to be executed. Within the text of command the characters `%' and `#' are expanded as in filenames and the character `!' is replaced with the text of the previous command. Thus, in particular, `!!' repeats the last such shell escape. If any such expansion is performed, the expanded line will be echoed. The current line is unchanged by this command.

    If there has been “[No write]” of the buffer contents since the last change to the editing buffer, then a diagnostic will be printed before the command is executed as a warning. A single `!' is printed when the command completes.

( addr , addr ) ! command
    Takes the specified address range and supplies it as standard input to command; the resulting output then replaces the input lines.

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

( . , . ) > count flags
( . , . ) < count flags
    Perform intelligent shifting on the specified lines; < shifts left and > shift right. The quantity of shift is determined by the shiftwidth option and the repetition of the specification character. Only white space (blanks and tabs) is shifted; no non-white characters are discarded in a left-shift. The current line becomes the last line which changed due to the shifting.

^D  An end-of-file from a terminal input scrolls through the file. The scroll option specifies the size of the scroll, normally a half screen of text.

( .+1 , .+1 )
( .+1 , .+1 ) |
    An address alone causes the addressed lines to be printed. A blank line prints the next line in the file.

( . , . ) & options count flags
    Repeats the previous substitute command.

( . , . ) ~ options count flags
    Replaces the previous regular expression with the previous replacement pattern from a substitution.

  Regular expressions

A regular expression specifies a set of strings of characters. A member of this set of strings is said to be matched by the regular expression. Ex remembers two previous regular expressions: the previous regular expression used in a substitute command and the previous regular expression used elsewhere (referred to as the previous scanning regular expression.) The previous regular expression can always be referred to by a null re, e.g. `//' or `??'.

The following basic constructs are used to construct magic mode regular expressions.

char
    An ordinary character matches itself. The characters `^' at the beginning of a line, `$' at the end of line, `*' as any character other than the first, `.', `\', `[', and `~' are not ordinary characters and must be escaped (preceded) by `\' to be treated as such.

^   At the beginning of a pattern forces the match to succeed only at the beginning of a line.

$   At the end of a regular expression forces the match to succeed only at the end of the line.

.   Matches any single character except the new-line character.

\<  Forces the match to occur only at the beginning of a “variable” or “word”; that is, either at the beginning of a line, or just before a letter, digit, or underline and after a character not one of these.

\>  Similar to `\<', but matching the end of a “variable” or “word”, i.e. either the end of the line or before character which is neither a letter, nor a digit, nor the underline character.

[string]
    Matches any (single) character in the class defined by string. Most characters in string define themselves. A pair of characters separated by `-' in string defines the set of characters collating between the specified lower and upper bounds, thus `[a-z]' as a regular expression matches any (single) lower-case letter. If the first character of string is an `^' then the construct matches those characters which it otherwise would not; thus `[^a-z]' matches anything but a lower-case letter (and of course a newline). Characters lose their special meaning by position: `^' is an ordinary character unless immediately following the initial `[', `]' is an ordinary character if immediately following the initial `[' (or `^', if present), and `-' is an ordinary character if placed immediately behind `[' or `^', or before ']'.

The concatenation of two regular expressions matches the leftmost and then longest string which can be divided with the first piece matching the first regular expression and the second piece matching the second.

Any of the (single character matching) regular expressions mentioned above may be followed by the character `*' to form a regular expression which matches any number of adjacent occurrences (including 0) of characters matched by the regular expression it follows.

A single character regular expression followed by `\{m,n\}' matches a sequence of m through n occurences, inclusive, of the single character expression. The values of m and n must be non-negative and smaller than 256. The form `\{m\}' matches exactly m occurences, `\{m,\}' matches at least m occurences.

The character `~' may be used in a regular expression, and matches the text which defined the replacement part of the last substitute command.

A regular expression may be enclosed between the sequences `\(' and `\)'.

The sequence `\n' matches the text that was matched by the n-th regular subexpression enclosed between `\(' and `\)' earlier in the expression.

  Substitute replacement patterns

The basic metacharacters for the replacement pattern are `&' and `~'; these are given as `\&' and `\~' when nomagic is set. Each instance of `&' is replaced by the characters which the regular expression matched. The metacharacter `~' stands, in the replacement pattern, for the defining text of the previous replacement pattern.

Other metasequences possible in the replacement pattern are always introduced by the escaping character `\'. The sequence `\n' is replaced by the text matched by the n-th regular subexpression enclosed between `\(' and `\)'. When nested, parenthesized subexpressions are present, n is determined by counting occurrences of `\(' starting from the left. The sequences `\u' and `\l' cause the immediately following character in the replacement to be converted to upper- or lower-case respectively if this character is a letter. The sequences `\U' and `\L' turn such conversion on, either until `\E' or `\e' is encountered, or until the end of the replacement pattern.

  Option descriptions

autoindent, ai	default: noai
    Can be used to ease the preparation of structured program text. At the beginning of each append , change or insert command or when a new line is opened or created by an append , change , insert , or substitute operation within open or visual mode, ex looks at the line being appended after, the first line changed or the line inserted before and calculates the amount of white space at the start of the line. It then aligns the cursor at the level of indentation so determined.

    If the user then types lines of text in, they will continue to be justified at the displayed indenting level. If more white space is typed at the beginning of a line, the following line will start aligned with the first non-white character of the previous line. To back the cursor up to the preceding tab stop one can hit ^D. The tab stops going backwards are defined at multiples of the shiftwidth option. The user cannot backspace over the indent, except by sending an end-of-file with a ^D.

    Specially processed in this mode is a line with no characters added to it, which turns into a completely blank line (the white space provided for the autoindent is discarded.) Also specially processed in this mode are lines beginning with an `^' and immediately followed by a ^D. This causes the input to be repositioned at the beginning of the line, but retaining the previous indent for the next line. Similarly, a `0' followed by a ^D repositions at the beginning but without retaining the previous indent.

    Autoindent doesn't happen in global commands or when the input is not a terminal.

autoprint, ap	default: ap
    Causes the current line to be printed after each delete , copy , join , move , substitute , t , undo or shift command. This has the same effect as supplying a trailing `p' to each such command. Autoprint is suppressed in globals, and only applies to the last of many commands on a line.

autowrite, aw	default: noaw
    Causes the contents of the buffer to be written to the current file if the user has modified it and gives a next, rewind, stop, tag, or ! command, or a ^^ (switch files) or ^] (tag goto) command in visual. Note, that the edit and ex commands do not autowrite. In each case, there is an equivalent way of switching when autowrite is set to avoid the autowrite (edit for next , rewind! for .I rewind , stop! for stop , tag! for tag , shell for ! , and :e # and a :ta! command from within visual).

beautify, bf	default: nobeautify
    Causes all control characters except tab, newline and form-feed to be discarded from the input. A complaint is registered the first time a backspace character is discarded. Beautify does not apply to command input.

directory, dir	default: dir=/tmp
    Specifies the directory in which ex places its buffer file. If this directory in not writable, then the editor will exit abruptly when it fails to be able to create its buffer there.

edcompatible	default: noedcompatible
    Causes the presence of absence of g and c suffixes on substitute commands to be remembered, and to be toggled by repeating the suffices. The suffix r makes the substitution be as in the ~ command, instead of like &.

errorbells, eb	default: noeb
    Error messages are preceded by a bell. Bell ringing in open and visual on errors is not suppressed by setting noeb. If possible the editor always places the error message in a standout mode of the terminal (such as inverse video) instead of ringing the bell.

exrc			default: noexrc
    If set, the current directory is searched for a .exrc file on startup. If this file is found, its content is treated as ex commands and executed immediately after the contents of $HOME/.exrc on startup.

flash, fl	default: flash
    If the terminal provides the “visual bell” capability, ex will use it instead of the audible bell if flash is set.

hardtabs, ht	default: ht=8
    Gives the boundaries on which terminal hardware tabs are set (or on which the system expands tabs).

ignorecase, ic	default: noic
    All upper case characters in the text are mapped to lower case in regular expression matching. In addition, all upper case characters in regular expressions are mapped to lower case except in character class specifications.

lisp	default: nolisp
    Autoindent indents appropriately for lisp code, and the ( ) { } [[ and ]] commands in open and visual are modified to have meaning for lisp.

list	default: nolist
    All printed lines will be displayed (more) unambiguously, showing tabs and end-of-lines as in the list command.

magic	default: magic for ex and vi, Nomagic for edit.
    If nomagic is set, the number of regular expression metacharacters is greatly reduced, with only `^' and `$' having special effects. In addition the metacharacters `~' and `&' of the replacement pattern are treated as normal characters. All the normal metacharacters may be made magic when nomagic is set by preceding them with a `\'.

mesg	default: mesg
    Causes write permission to be turned off to the terminal while the user is in visual mode, if nomesg is set.

modelines, ml	default: nomodelines
    If modelines is set, then the first 5 lines and the last five lines of the file will be checked for ex command lines and the comands issued. To be recognized as a command line, the line must have the string ex: or vi: in it. This string may be anywhere in the line and anything after the : is interpeted as editor commands. This option defaults to off because of unexpected behavior when editting files such as /etc/passwd.

number, nu	default: nonumber
    Causes all output lines to be printed with their line numbers. In addition each input line will be prompted for by supplying the line number it will have.

open	default: open
    If noopen, the commands open and visual are not permitted.

optimize, opt	default: optimize
    Throughput of text is expedited by setting the terminal to not do automatic carriage returns when printing more than one (logical) line of output, greatly speeding output on terminals without addressable cursors when text with leading white space is printed.

paragraphs, para	default: para=IPLPPPQPP LIbp
    Specifies the paragraphs for the { and } operations in open and visual. The pairs of characters in the option's value are the names of the macros which start paragraphs.

prompt	default: prompt
    Command mode input is prompted for with a `:'.

redraw	default: noredraw
    The editor simulates (using great amounts of output), an intelligent terminal on a dumb terminal (e.g. during insertions in visual the characters to the right of the cursor position are refreshed as each input character is typed.) Useful only at very high speed.

remap	default: remap
    If on, macros are repeatedly tried until they are unchanged. For example, if o is mapped to O , and O is mapped to I , then if remap is set, o will map to I , but if noremap is set, it will map to O .

report	default: report=5, 2 for edit.
    Specifies a threshold for feedback from commands. Any command which modifies more than the specified number of lines will provide feedback as to the scope of its changes. For commands such as global , open , undo , and visual which have potentially more far reaching scope, the net change in the number of lines in the buffer is presented at the end of the command, subject to this same threshold. Thus notification is suppressed during a global command on the individual commands performed.

scroll	default: scroll=½ window
    Determines the number of logical lines scrolled when an end-of-file is received from a terminal input in command mode, and the number of lines printed by a command mode z command (double the value of scroll ).

sections	default: sections=SHNHH HU
    Specifies the section macros for the [[ and ]] operations in open and visual. The pairs of characters in the options's value are the names of the macros which start paragraphs.

shell, sh	default: sh=/bin/sh
    Gives the path name of the shell forked for the shell escape command `!', and by the shell command. The default is taken from SHELL in the environment, if present.

shiftwidth, sw	default: sw=8
    Gives the width a software tab stop, used in reverse tabbing with ^D when using autoindent to append text, and by the shift commands.

showmatch, sm	default: nosm
    In open and visual mode, when a ) or } is typed, move the cursor to the matching ( or { for one second if this matching character is on the screen. Extremely useful with lisp.

showmode, smd	default: nosmd
    In visual mode, show a description of the current editing mode in the window's lower right corner.

slowopen, slow	terminal dependent
    Affects the display algorithm used in visual mode, holding off display updating during input of new text to improve throughput when the terminal in use is both slow and unintelligent. See An Introduction to Display Editing with Vi for more details.

tabstop, ts	default: ts=8
    The editor expands tabs in the input file to be on tabstop boundaries for the purposes of display.

taglength, tl	default: tl=0
    Tags are not significant beyond this many characters. A value of zero (the default) means that all characters are significant.

tags	default: tags=tags /usr/lib/tags
    A path of files to be used as tag files for the tag command. A requested tag is searched for in the specified files, sequentially. By default, files called tags are searched for in the current directory and in /usr/lib (a master file for the entire system).

term	from environment TERM
    The terminal type of the output device.

terse	default: noterse
    Shorter error diagnostics are produced for the experienced user.

warn	default: warn
    Warn if there has been `[No write since last change]' before a `!' command escape.

window	default: window=speed dependent
    The number of lines in a text window in the visual command. The default is 8 at slow speeds (600 baud or less), 16 at medium speed (1200 baud), and the full screen (minus one line) at higher speeds.

w300, w1200, w9600
    These are not true options but set window only if the speed is slow (300), medium (1200), or high (9600), respectively. They are suitable for an EXINIT and make it easy to change the 8/16/full screen rule.

wrapscan, ws	default: ws
    Searches using the regular expressions in addressing will wrap around past the end of the file.

wrapmargin, wm	default: wm=0
    Defines a margin for automatic wrapover of text during input in open and visual modes. See An Introduction to Text Editing with Vi for details.

writeany, wa	default: nowa

    Inhibit the checks normally made before write commands, allowing a write to any file which the system protection mechanism will allow.

ENVIRONMENT VARIABLES

The following environment variables affect the behaviour of ex:

COLUMNS
    Overrides the system-supplied number of terminal columns.

EXINIT
    Contains commands to execute at editor startup. If this variable is present, the .exrc file in the user's home directory is ignored.

HOME
    Used to locate the editor startup file.

LANG,  LC_ALL,  LC_CTYPE,  LC_MESSAGES
    See locale(7).

LINES
    Overrides the system-supplied number of terminal lines.

SHELL
    The program file used to execute external commands.

TERM
    Determines the terminal type.

FILES

/usr/libexec/expreserve
    preserve command

/usr/libexec/exrecover
    recover command

/etc/termcap
    describes capabilities of terminals

$HOME/.exrc
    editor startup file

/var/tmp/Exnnnnnnnnnn
    editor temporary

/var/tmp/Rxnnnnnnnnnn
    named buffer temporary

/var/preserve
    preservation directory

DOCUMENTATION
The document Edit: A tutorial (USD:14) provides a comprehensive introduction to edit assuming no previous knowledge of computers or the UNIX system.

The Ex Reference Manual – Version 3.7 (USD:16) is a comprehensive and complete manual for the command mode features of ex. The USAGE section of this page is taken from the manual. For an introduction to more advanced forms of editing using the command mode of ex see the editing documents written by Brian Kernighan for the editor ed; the material in the introductory and advanced documents works also with ex.

An Introduction to Display Editing with Vi (USD:15) introduces the display editor vi and provides reference material on vi. (This reference now forms the vi(1) manual page). In addition, the Vi Quick Reference card summarizes the commands of vi in a useful, functional way, and is useful with the Introduction.

SEE ALSO
awk(1), ed(1), grep(1), sed(1), grep(1), vi(1), termcap(5), environ(7), locale(7), regex(7)

AUTHOR
Originally written by William Joy.

Mark Horton has maintained the editor since version 2.7, adding macros, support for many unusual terminals, and other features such as word abbreviation mode.

This version incorporates changes by Gunnar Ritter.

NOTES
Undo never clears the buffer modified condition.

The z command prints a number of logical rather than physical lines. More than a screen full of output may result if long lines are present.

File input/output errors don't print a name if the command line `-' option is used.

The editor does not warn if text is placed in named buffers and not used before exiting the editor.

Null (00) characters are converted to 0200 characters when reading input files, and cannot appear in resultant files.