NAME

ex - text editor

SYNOPSIS

[UP] ex [-rR][-s | -v][-c command][-t tagstring][-w size][file ...]

DESCRIPTION

The ex utility is a line-oriented text editor. There are two other modes of the editor-open and visual-in which screen-oriented editing is available. This is described more fully by the ex open and visual commands and in vi.

This section uses the term edit buffer to describe the current working text. No specific implementation is implied by this term. All editing changes are performed on the edit buffer, and no changes to it shall affect any file until an editor command writes the file.

Certain terminals do not have all the capabilities necessary to support the complete ex definition, such as the full-screen editing commands ( visual mode or open mode). When these commands cannot be supported on such terminals, this condition shall not produce an error message such as "not an editor command" or report a syntax error. The implementation may either accept the commands and produce results on the screen that are the result of an unsuccessful attempt to meet the requirements of this volume of IEEE Std 1003.1-2001 or report an error describing the terminal-related deficiency.

OPTIONS

The ex utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.

The following options shall be supported:

-c  command

Specify an initial command to be executed in the first edit buffer loaded from an existing file (see the EXTENDED DESCRIPTION section). Implementations may support more than a single -c option. In such implementations, the specified commands shall be executed in the order specified on the command line.

-r

Recover the named files (see the EXTENDED DESCRIPTION section). Recovery information for a file shall be saved during an editor or system crash (for example, when the editor is terminated by a signal which the editor can catch), or after the use of an ex preserve command.

A crash in this context is an unexpected failure of the system or utility that requires restarting the failed system or utility. A system crash implies that any utilities running at the time also crash. In the case of an editor or system crash, the number of changes to the edit buffer (since the most recent preserve command) that will be recovered is unspecified.

If no file operands are given and the -t option is not specified, all other options, the EXINIT variable, and any .exrc files shall be ignored; a list of all recoverable files available to the invoking user shall be written, and the editor shall exit normally without further action.

-R

Set readonly edit option.

-s

Prepare ex for batch use by taking the following actions:

• Suppress writing prompts and informational (but not diagnostic) messages.

• Ignore the value of TERM and any implementation default terminal type and assume the terminal is a type incapable of supporting open or visual modes; see the visual command and the description of vi.

• Suppress the use of the EXINIT environment variable and the reading of any .exrc file; see the EXTENDED DESCRIPTION section.

• Suppress autoindentation, ignoring the value of the autoindent edit option.

-t  tagstring

Edit the file containing the specified tagstring; see ctags. The tags feature represented by -t tagstring and the tag command is optional. It shall be provided on any system that also provides a conforming implementation of ctags; otherwise, the use of -t produces undefined results. On any system, it shall be an error to specify more than a single -t option.

-v

Begin in visual mode (see vi).

-w  size

Set the value of the window editor option to size.

OPERANDS

The following operand shall be supported:

file

A pathname of a file to be edited.

STDIN

The standard input consists of a series of commands and input text, as described in the EXTENDED DESCRIPTION section. The implementation may limit each line of standard input to a length of {LINE_MAX}.

If the standard input is not a terminal device, it shall be as if the -s option had been specified.

If a read from the standard input returns an error, or if the editor detects an end-of-file condition from the standard input, it shall be equivalent to a SIGHUP asynchronous event.

INPUT FILES

Input files shall be text files or files that would be text files except for an incomplete last line that is not longer than {LINE_MAX}-1 bytes in length and contains no NUL characters. By default, any incomplete last line shall be treated as if it had a trailing <newline>. The editing of other forms of files may optionally be allowed by ex implementations.

The .exrc files and source files shall be text files consisting of ex commands; see the EXTENDED DESCRIPTION section.

By default, the editor shall read lines from the files to be edited without interpreting any of those lines as any form of editor command.

ENVIRONMENT VARIABLES

The following environment variables shall affect the execution of ex:

COLUMNS

Override the system-selected horizontal screen size. See the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 8, Environment Variables for valid values and results when it is unset or null.

EXINIT

Determine a list of ex commands that are executed on editor start-up. See the EXTENDED DESCRIPTION section for more details of the initialization phase.

HOME

Determine a pathname of a directory that shall be searched for an editor start-up file named .exrc; see the EXTENDED DESCRIPTION section.

LANG

Provide a default value for the internationalization variables that are unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale categories.)

LC_ALL

If set to a non-empty string value, override the values of all the other internationalization variables.

LC_COLLATE

Determine the locale for the behavior of ranges, equivalence classes, and multi-character collating elements within regular expressions.

LC_CTYPE

Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi-byte characters in arguments and input files), the behavior of character classes within regular expressions, the classification of characters as uppercase or lowercase letters, the case conversion of letters, and the detection of word boundaries.

LC_MESSAGES

Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error.

LINES

Override the system-selected vertical screen size, used as the number of lines in a screenful and the vertical screen size in visual mode. See the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 8, Environment Variables for valid values and results when it is unset or null.

NLSPATH

^[XSI] Determine the location of message catalogs for the processing of LC_MESSAGES .

PATH

Determine the search path for the shell command specified in the ex editor commands !, shell, read, and write, and the open and visual mode command !; see the description of command search and execution in Command Search and Execution.

SHELL

Determine the preferred command line interpreter for use as the default value of the shell edit option.

TERM

Determine the name of the terminal type. If this variable is unset or null, an unspecified default terminal type shall be used.

ASYNCHRONOUS EVENTS

The following term is used in this and following sections to specify command and asynchronous event actions:

complete write

A complete write is a write of the entire contents of the edit buffer to a file of a type other than a terminal device, or the saving of the edit buffer caused by the user executing the ex preserve command. Writing the contents of the edit buffer to a temporary file that will be removed when the editor exits shall not be considered a complete write.

The following actions shall be taken upon receipt of signals:

SIGINT

If the standard input is not a terminal device, ex shall not write the file or return to command or text input mode, and shall exit with a non-zero exit status.

Otherwise, if executing an open or visual text input mode command, ex in receipt of SIGINT shall behave identically to its receipt of the <ESC> character.

Otherwise:

1. If executing an ex text input mode command, all input lines that have been completely entered shall be resolved into the edit buffer, and any partially entered line shall be discarded.

2. If there is a currently executing command, it shall be aborted and a message displayed. Unless otherwise specified by the ex or vi command descriptions, it is unspecified whether any lines modified by the executing command appear modified, or as they were before being modified by the executing command, in the buffer.

   If the currently executing command was a motion command, its associated command shall be discarded.

3. If in open or visual command mode, the terminal shall be alerted.

4. The editor shall then return to command mode.

SIGCONT

The screen shall be refreshed if in open or visual mode.

SIGHUP

If the edit buffer has been modified since the last complete write, ex shall attempt to save the edit buffer so that it can be recovered later using the -r option or the ex recover command. The editor shall not write the file or return to command or text input mode, and shall terminate with a non-zero exit status.

SIGTERM

Refer to SIGHUP.

The action taken for all other signals is unspecified.

STDOUT

The standard output shall be used only for writing prompts to the user, for informational messages, and for writing lines from the file.

STDERR

The standard error shall be used only for diagnostic messages.

OUTPUT FILES

The output from ex shall be text files.

EXTENDED DESCRIPTION

Only the ex mode of the editor is described in this section. See vi for additional editing capabilities available in ex.

When an error occurs, ex shall write a message. If the terminal supports a standout mode (such as inverse video), the message shall be written in standout mode. If the terminal does not support a standout mode, and the edit option errorbells is set, an alert action shall precede the error message.

By default, ex shall start in command mode, which shall be indicated by a : prompt; see the prompt command. Text input mode can be entered by the append, insert, or change commands; it can be exited (and command mode re-entered) by typing a period ( '.' ) alone at the beginning of a line.

Initialization in ex and vi

The following symbols are used in this and following sections to specify locations in the edit buffer:

alternate and current pathnames

Two pathnames, named current and alternate, are maintained by the editor. Any ex commands that take filenames as arguments shall set them as follows:

1. If a file argument is specified to the ex edit, ex, or recover commands, or if an ex tag command replaces the contents of the edit buffer.

   1. If the command replaces the contents of the edit buffer, the current pathname shall be set to the file argument or the file indicated by the tag, and the alternate pathname shall be set to the previous value of the current pathname.

   2. Otherwise, the alternate pathname shall be set to the file argument.

2. If a file argument is specified to the ex next command:

   1. If the command replaces the contents of the edit buffer, the current pathname shall be set to the first file argument, and the alternate pathname shall be set to the previous value of the current pathname.

3. If a file argument is specified to the ex file command, the current pathname shall be set to the file argument, and the alternate pathname shall be set to the previous value of the current pathname.

4. If a file argument is specified to the ex read and write commands (that is, when reading or writing a file, and not to the program named by the shell edit option), or a file argument is specified to the ex xit command:

   1. If the current pathname has no value, the current pathname shall be set to the file argument.

   2. Otherwise, the alternate pathname shall be set to the file argument.

If the alternate pathname is set to the previous value of the current pathname when the current pathname had no previous value, then the alternate pathname shall have no value as a result.

current line

The line of the edit buffer referenced by the cursor. Each command description specifies the current line after the command has been executed, as the current line value. When the edit buffer contains no lines, the current line shall be zero; see Addressing in ex.

current column

The current display line column occupied by the cursor. (The columns shall be numbered beginning at 1.) Each command description specifies the current column after the command has been executed, as the current column value. This column is an ideal column that is remembered over the lifetime of the editor. The actual display line column upon which the cursor rests may be different from the current column; see the cursor positioning discussion in Command Descriptions in vi.

set to non-<blank>

A description for a current column value, meaning that the current column shall be set to the last display line column on which is displayed any part of the first non- <blank> of the line. If the line has no non- <blank> non- <newline>s, the current column shall be set to the last display line column on which is displayed any part of the last non- <newline> in the line. If the line is empty, the current column shall be set to column position 1.

The length of lines in the edit buffer may be limited to {LINE_MAX} bytes. In open and visual mode, the length of lines in the edit buffer may be limited to the number of characters that will fit in the display. If either limit is exceeded during editing, an error message shall be written. If either limit is exceeded by a line read in from a file, an error message shall be written and the edit session may be terminated.

If the editor stops running due to any reason other than a user command, and the edit buffer has been modified since the last complete write, it shall be equivalent to a SIGHUP asynchronous event. If the system crashes, it shall be equivalent to a SIGHUP asynchronous event.

During initialization (before the first file is copied into the edit buffer or any user commands from the terminal are processed) the following shall occur:

1. If the environment variable EXINIT is set, the editor shall execute the ex commands contained in that variable.

2. If the EXINIT variable is not set, and all of the following are true:

   1. The HOME environment variable is not null and not empty.

   2. The file .exrc in the directory referred to by the HOME environment variable:

      1. Exists

      2. Is owned by the same user ID as the real user ID of the process or the process has appropriate privileges

      3. Is not writable by anyone other than the owner

   the editor shall execute the ex commands contained in that file.

3. If and only if all of the following are true:

   1. The current directory is not referred to by the HOME environment variable.

   2. A command in the EXINIT environment variable or a command in the .exrc file in the directory referred to by the HOME environment variable sets the editor option exrc.

   3. The .exrc file in the current directory:

      1. Exists

      2. Is owned by the same user ID as the real user ID of the process, or by one of a set of implementation-defined user IDs

      3. Is not writable by anyone other than the owner

   the editor shall attempt to execute the ex commands contained in that file.

Lines in any .exrc file that are blank lines shall be ignored. If any .exrc file exists, but is not read for ownership or permission reasons, it shall be an error.

After the EXINIT variable and any .exrc files are processed, the first file specified by the user shall be edited, as follows:

1. If the user specified the -t option, the effect shall be as if the ex tag command was entered with the specified argument, with the exception that if tag processing does not result in a file to edit, the effect shall be as described in step 3. below.

2. Otherwise, if the user specified any command line file arguments, the effect shall be as if the ex edit command was entered with the first of those arguments as its file argument.

3. Otherwise, the effect shall be as if the ex edit command was entered with a nonexistent filename as its file argument. It is unspecified whether this action shall set the current pathname. In an implementation where this action does not set the current pathname, any editor command using the current pathname shall fail until an editor command sets the current pathname.

If the -r option was specified, the first time a file in the initial argument list or a file specified by the -t option is edited, if recovery information has previously been saved about it, that information shall be recovered and the editor shall behave as if the contents of the edit buffer have already been modified. If there are multiple instances of the file to be recovered, the one most recently saved shall be recovered, and an informational message that there are previous versions of the file that can be recovered shall be written. If no recovery information about a file is available, an informational message to this effect shall be written, and the edit shall proceed as usual.

If the -c option was specified, the first time a file that already exists (including a file that might not exist but for which recovery information is available, when the -r option is specified) replaces or initializes the contents of the edit buffer, the current line shall be set to the last line of the edit buffer, the current column shall be set to non- <blank>, and the ex commands specified with the -c option shall be executed. In this case, the current line and current column shall not be set as described for the command associated with the replacement or initialization of the edit buffer contents. However, if the -t option or a tag command is associated with this action, the -c option commands shall be executed and then the movement to the tag shall be performed.

The current argument list shall initially be set to the filenames specified by the user on the command line. If no filenames are specified by the user, the current argument list shall be empty. If the -t option was specified, it is unspecified whether any filename resulting from tag processing shall be prepended to the current argument list. In the case where the filename is added as a prefix to the current argument list, the current argument list reference shall be set to that filename. In the case where the filename is not added as a prefix to the current argument list, the current argument list reference shall logically be located before the first of the filenames specified on the command line (for example, a subsequent ex next command shall edit the first filename from the command line). If the -t option was not specified, the current argument list reference shall be to the first of the filenames on the command line.

Addressing in ex

Addressing in ex relates to the current line and the current column; the address of a line is its 1-based line number, the address of a column is its 1-based count from the beginning of the line. Generally, the current line is the last line affected by a command. The current line number is the address of the current line. In each command description, the effect of the command on the current line number and the current column is described.

Addresses are constructed as follows:

1. The character '.' (period) shall address the current line.

2. The character '$' shall address the last line of the edit buffer.

3. The positive decimal number n shall address the nth line of the edit buffer.

4. The address "'x" refers to the line marked with the mark name character 'x', which shall be a lowercase letter from the portable character set or one of the characters '`' or '". It shall be an error if the line that was marked is not currently present in the edit buffer or the mark has not been set. Lines can be marked with the ex mark or k commands, or the vi m command.

5. A regular expression enclosed by slashes ( '/' ) shall address the first line found by searching forwards from the line following the current line toward the end of the edit buffer and stopping at the first line for which the line excluding the terminating <newline> matches the regular expression. As stated in Regular Expressions in ex , an address consisting of a null regular expression delimited by slashes "//" shall address the next line for which the line excluding the terminating <newline> matches the last regular expression encountered. In addition, the second slash can be omitted at the end of a command line. If the wrapscan edit option is set, the search shall wrap around to the beginning of the edit buffer and continue up to and including the current line, so that the entire edit buffer is searched. Within the regular expression, the sequence "\/" shall represent a literal slash instead of the regular expression delimiter.

6. A regular expression enclosed in question marks ( '?' ) shall address the first line found by searching backwards from the line preceding the current line toward the beginning of the edit buffer and stopping at the first line for which the line excluding the terminating <newline> matches the regular expression. An address consisting of a null regular expression delimited by question marks "??" shall address the previous line for which the line excluding the terminating <newline> matches the last regular expression encountered. In addition, the second question mark can be omitted at the end of a command line. If the wrapscan edit option is set, the search shall wrap around from the beginning of the edit buffer to the end of the edit buffer and continue up to and including the current line, so that the entire edit buffer is searched. Within the regular expression, the sequence "\?" shall represent a literal question mark instead of the RE delimiter.

7. A plus sign ( '+' ) or a minus sign ( '-' ) followed by a decimal number shall address the current line plus or minus the number. A '+' or '-' not followed by a decimal number shall address the current line plus or minus 1.

Addresses can be followed by zero or more address offsets, optionally <blank>-separated. Address offsets are constructed as follows:

1. A '+' or '-' immediately followed by a decimal number shall add (subtract) the indicated number of lines to (from) the address. A '+' or '-' not followed by a decimal number shall add (subtract) 1 to (from) the address.

2. A decimal number shall add the indicated number of lines to the address.

It shall not be an error for an intermediate address value to be less than zero or greater than the last line in the edit buffer. It shall be an error for the final address value to be less than zero or greater than the last line in the edit buffer.

Commands take zero, one, or two addresses; see the descriptions of 1addr and 2addr in Command Descriptions in ex. If more than the required number of addresses are provided to a command that requires zero addresses, it shall be an error. Otherwise, if more than the required number of addresses are provided to a command, the addresses specified first shall be evaluated and then discarded until the maximum number of valid addresses remain.

Addresses shall be separated from each other by a comma ( ',' ) or a semicolon ( ';' ). If no address is specified before or after a comma or semicolon separator, it shall be as if the address of the current line was specified before or after the separator. In the case of a semicolon separator, the current line ( '.' ) shall be set to the first address, and only then will the next address be calculated. This feature can be used to determine the starting line for forwards and backwards searches (see rules 5. and 6.).

A percent sign ( '%' ) shall be equivalent to entering the two addresses "1,$".

Any delimiting <blank>s between addresses, address separators, or address offsets shall be discarded.

Command Line Parsing in ex

The following symbol is used in this and following sections to describe parsing behavior:

escape

If a character is referred to as "backslash-escaped" or " <control>-V-escaped," it shall mean that the character acquired or lost a special meaning by virtue of being preceded, respectively, by a backslash or <control>-V character. Unless otherwise specified, the escaping character shall be discarded at that time and shall not be further considered for any purpose.

Command-line parsing shall be done in the following steps. For each step, characters already evaluated shall be ignored; that is, the phrase "leading character" refers to the next character that has not yet been evaluated.

1. Leading colon characters shall be skipped.

2. Leading <blank>s shall be skipped.

3. If the leading character is a double-quote character, the characters up to and including the next non-backslash-escaped <newline> shall be discarded, and any subsequent characters shall be parsed as a separate command.

4. Leading characters that can be interpreted as addresses shall be evaluated; see Addressing in ex .

5. Leading <blank>s shall be skipped.

6. If the next character is a vertical-line character or a <newline>:

   1. If the next character is a <newline>:

      1. If ex is in open or visual mode, the current line shall be set to the last address specified, if any.

      2. Otherwise, if the last command was terminated by a vertical-line character, no action shall be taken; for example, the command "||<newline>" shall execute two implied commands, not three.

      3. Otherwise, step 6.b. shall apply.

   2. Otherwise, the implied command shall be the print command. The last #, p, and l flags specified to any ex command shall be remembered and shall apply to this implied command. Executing the ex number, print, or list command shall set the remembered flags to #, nothing, and l, respectively, plus any other flags specified for that execution of the number, print, or list command.

      If ex is not currently performing a global or v command, and no address or count is specified, the current line shall be incremented by 1 before the command is executed. If incrementing the current line would result in an address past the last line in the edit buffer, the command shall fail, and the increment shall not happen.

   3. The <newline> or vertical-line character shall be discarded and any subsequent characters shall be parsed as a separate command.

7. The command name shall be comprised of the next character (if the character is not alphabetic), or the next character and any subsequent alphabetic characters (if the character is alphabetic), with the following exceptions:

   1. Commands that consist of any prefix of the characters in the command name delete, followed immediately by any of the characters 'l', 'p', '+', '-', or '#' shall be interpreted as a delete command, followed by a <blank>, followed by the characters that were not part of the prefix of the delete command. The maximum number of characters shall be matched to the command name delete; for example, "del" shall not be treated as "de" followed by the flag l.

   2. Commands that consist of the character 'k', followed by a character that can be used as the name of a mark, shall be equivalent to the mark command followed by a <blank>, followed by the character that followed the 'k'.

   3. Commands that consist of the character 's', followed by characters that could be interpreted as valid options to the s command, shall be the equivalent of the s command, without any pattern or replacement values, followed by a <blank>, followed by the characters after the 's'.

8. The command name shall be matched against the possible command names, and a command name that contains a prefix matching the characters specified by the user shall be the executed command. In the case of commands where the characters specified by the user could be ambiguous, the executed command shall be as follows:

   a	append	n	next	t	t
   c	change	p	print	u	undo
   ch	change	pr	print	un	undo
   e	edit	r	read	v	v
   m	move	re	read	w	write
   ma	mark	s	s

   Implementation extensions with names causing similar ambiguities shall not be checked for a match until all possible matches for commands specified by IEEE Std 1003.1-2001 have been checked.

9. If the command is a ! command, or if the command is a read command followed by zero or more <blank>s and a !, or if the command is a write command followed by one or more <blank>s and a !, the rest of the command shall include all characters up to a non-backslash-escaped <newline>. The <newline> shall be discarded and any subsequent characters shall be parsed as a separate ex command.

10. Otherwise, if the command is an edit, ex, or next command, or a visual command while in open or visual mode, the next part of the command shall be parsed as follows:

    1. Any '!' character immediately following the command shall be skipped and be part of the command.

    2. Any leading <blank>s shall be skipped and be part of the command.

    3. If the next character is a '+', characters up to the first non-backslash-escaped <newline> or non-backslash-escaped <blank> shall be skipped and be part of the command.

    4. The rest of the command shall be determined by the steps specified in paragraph 12.

11. Otherwise, if the command is a global, open, s, or v command, the next part of the command shall be parsed as follows:

    1. Any leading <blank>s shall be skipped and be part of the command.

    2. If the next character is not an alphanumeric, double-quote, <newline>, backslash, or vertical-line character:

       1. The next character shall be used as a command delimiter.

       2. If the command is a global, open, or v command, characters up to the first non-backslash-escaped <newline>, or first non-backslash-escaped delimiter character, shall be skipped and be part of the command.

       3. If the command is an s command, characters up to the first non-backslash-escaped <newline>, or second non-backslash-escaped delimiter character, shall be skipped and be part of the command.

    3. If the command is a global or v command, characters up to the first non-backslash-escaped <newline> shall be skipped and be part of the command.

    4. Otherwise, the rest of the command shall be determined by the steps specified in paragraph 12.

12. Otherwise:

    1. If the command was a map, unmap, abbreviate, or unabbreviate command, characters up to the first non- <control>-V-escaped <newline>, vertical-line, or double-quote character shall be skipped and be part of the command.

    2. Otherwise, characters up to the first non-backslash-escaped <newline>, vertical-line, or double-quote character shall be skipped and be part of the command.

    3. If the command was an append, change, or insert command, and the step 12.b. ended at a vertical-line character, any subsequent characters, up to the next non-backslash-escaped <newline> shall be used as input text to the command.

    4. If the command was ended by a double-quote character, all subsequent characters, up to the next non-backslash-escaped <newline>, shall be discarded.

    5. The terminating <newline> or vertical-line character shall be discarded and any subsequent characters shall be parsed as a separate ex command.

Command arguments shall be parsed as described by the Synopsis and Description of each individual ex command. This parsing shall not be <blank>-sensitive, except for the ! argument, which must follow the command name without intervening <blank>s, and where it would otherwise be ambiguous. For example, count and flag arguments need not be <blank>-separated because "d22p" is not ambiguous, but file arguments to the ex next command must be separated by one or more <blank>s. Any <blank> in command arguments for the abbreviate, unabbreviate, map, and unmap commands can be <control>-V-escaped, in which case the <blank> shall not be used as an argument delimiter. Any <blank> in the command argument for any other command can be backslash-escaped, in which case that <blank> shall not be used as an argument delimiter.

Within command arguments for the abbreviate, unabbreviate, map, and unmap commands, any character can be <control>-V-escaped. All such escaped characters shall be treated literally and shall have no special meaning. Within command arguments for all other ex commands that are not regular expressions or replacement strings, any character that would otherwise have a special meaning can be backslash-escaped. Escaped characters shall be treated literally, without special meaning as shell expansion characters or '!', '%', and '#' expansion characters. See Regular Expressions in ex and Replacement Strings in ex for descriptions of command arguments that are regular expressions or replacement strings.

Non-backslash-escaped '%' characters appearing in file arguments to any ex command shall be replaced by the current pathname; unescaped '#' characters shall be replaced by the alternate pathname. It shall be an error if '%' or '#' characters appear unescaped in an argument and their corresponding values are not set.

Non-backslash-escaped '!' characters in the arguments to either the ex ! command or the open and visual mode ! command, or in the arguments to the ex read command, where the first non- <blank> after the command name is a '!' character, or in the arguments to the ex write command where the command name is followed by one or more <blank>s and the first non- <blank> after the command name is a '!' character, shall be replaced with the arguments to the last of those three commands as they appeared after all unescaped '%', '#' , and '!' characters were replaced. It shall be an error if '!' characters appear unescaped in one of these commands and there has been no previous execution of one of these commands.

If an error occurs during the parsing or execution of an ex command:

• An informational message to this effect shall be written. Execution of the ex command shall stop, and the cursor (for example, the current line and column) shall not be further modified.

• If the ex command resulted from a map expansion, all characters from that map expansion shall be discarded, except as otherwise specified by the map command.

• Otherwise, if the ex command resulted from the processing of an EXINIT environment variable, a .exrc file, a :source command, a -c option, or a + command specified to an ex edit, ex, next, or visual command, no further commands from the source of the commands shall be executed.

• Otherwise, if the ex command resulted from the execution of a buffer or a global or v command, no further commands caused by the execution of the buffer or the global or v command shall be executed.

• Otherwise, if the ex command was not terminated by a <newline>, all characters up to and including the next non-backslash-escaped <newline> shall be discarded.

Input Editing in ex

The following symbol is used in this and the following sections to specify command actions:

word

In the POSIX locale, a word consists of a maximal sequence of letters, digits, and underscores, delimited at both ends by characters other than letters, digits, or underscores, or by the beginning or end of a line or the edit buffer.

When accepting input characters from the user, in either ex command mode or ex text input mode, ex shall enable canonical mode input processing, as defined in the System Interfaces volume of IEEE Std 1003.1-2001.

If in ex text input mode:

1. If the number edit option is set, ex shall prompt for input using the line number that would be assigned to the line if it is entered, in the format specified for the ex number command.

2. If the autoindent edit option is set, ex shall prompt for input using autoindent characters, as described by the autoindent edit option. autoindent characters shall follow the line number, if any.

If in ex command mode:

1. If the prompt edit option is set, input shall be prompted for using a single ':' character; otherwise, there shall be no prompt.

The input characters in the following sections shall have the following effects on the input line.

Scroll

Synopsis:

eof

See the description of the stty eof character in stty.

If in ex command mode:

If the eof character is the first character entered on the line, the line shall be evaluated as if it contained two characters: a <control>-D and a <newline>.

Otherwise, the eof character shall have no special meaning.

If in ex text input mode:

If the cursor follows an autoindent character, the autoindent characters in the line shall be modified so that a part of the next text input character will be displayed on the first column in the line after the previous shiftwidth edit option column boundary, and the user shall be prompted again for input for the same line.

Otherwise, if the cursor follows a '0', which follows an autoindent character, and the '0' was the previous text input character, the '0' and all autoindent characters in the line shall be discarded, and the user shall be prompted again for input for the same line.

Otherwise, if the cursor follows a '^', which follows an autoindent character, and the '^' was the previous text input character, the '^' and all autoindent characters in the line shall be discarded, and the user shall be prompted again for input for the same line. In addition, the autoindent level for the next input line shall be derived from the same line from which the autoindent level for the current input line was derived.

Otherwise, if there are no autoindent or text input characters in the line, the eof character shall be discarded.

Otherwise, the eof character shall have no special meaning.

<newline>

Synopsis:

<newline>


<control>-J

If in ex command mode:

Cause the command line to be parsed; <control>-J shall be mapped to the <newline> for this purpose.

If in ex text input mode:

Terminate the current line. If there are no characters other than autoindent characters on the line, all characters on the line shall be discarded.

Prompt for text input on a new line after the current line. If the autoindent edit option is set, an appropriate number of autoindent characters shall be added as a prefix to the line as described by the ex autoindent edit option.

<backslash>

Synopsis:

<backslash>

Allow the entry of a subsequent <newline> or <control>-J as a literal character, removing any special meaning that it may have to the editor during text input mode. The backslash character shall be retained and evaluated when the command line is parsed, or retained and included when the input text becomes part of the edit buffer.

<control>-V

Synopsis:

<control>-V

Allow the entry of any subsequent character as a literal character, removing any special meaning that it may have to the editor during text input mode. The <control>-V character shall be discarded before the command line is parsed or the input text becomes part of the edit buffer.

If the "literal next" functionality is performed by the underlying system, it is implementation-defined whether a character other than <control>-V performs this function.

<control>-W

Synopsis:

<control>-W

Discard the <control>-W, and the word previous to it in the input line, including any <blank>s following the word and preceding the <control>-W. If the "word erase" functionality is performed by the underlying system, it is implementation-defined whether a character other than <control>-W performs this function.

Command Descriptions in ex

The following symbols are used in this section to represent command modifiers. Some of these modifiers can be omitted, in which case the specified defaults shall be used.

1addr

A single line address, given in any of the forms described in Addressing in ex; the default shall be the current line ( '.' ), unless otherwise specified.

If the line address is zero, it shall be an error, unless otherwise specified in the following command descriptions.

If the edit buffer is empty, and the address is specified with a command other than =, append, insert, open, put, read, or visual, or the address is not zero, it shall be an error.

2addr

Two addresses specifying an inclusive range of lines. If no addresses are specified, the default for 2addr shall be the current line only ( ".,." ), unless otherwise specified in the following command descriptions. If one address is specified, 2addr shall specify that line only, unless otherwise specified in the following command descriptions.

It shall be an error if the first address is greater than the second address.

If the edit buffer is empty, and the two addresses are specified with a command other than the !, write, wq, or xit commands, or either address is not zero, it shall be an error.

count

A positive decimal number. If count is specified, it shall be equivalent to specifying an additional address to the command, unless otherwise specified by the following command descriptions. The additional address shall be equal to the last address specified to the command (either explicitly or by default) plus count-1.

If this would result in an address greater than the last line of the edit buffer, it shall be corrected to equal the last line of the edit buffer.

flags

One or more of the characters '+', '-', '#', 'p', or 'l' (ell). The flag characters can be <blank>-separated, and in any order or combination. The characters '#', 'p', and 'l' shall cause lines to be written in the format specified by the print command with the specified flags.

The lines to be written are as follows:

1. All edit buffer lines written during the execution of the ex &, ˜, list, number, open, print, s, visual, and z commands shall be written as specified by flags.

2. After the completion of an ex command with a flag as an argument, the current line shall be written as specified by flags, unless the current line was the last line written by the command.

The characters '+' and '-' cause the value of the current line after the execution of the ex command to be adjusted by the offset address as described in Addressing in ex. This adjustment shall occur before the current line is written as described in 2. above.

The default for flags shall be none.

buffer

One of a number of named areas for holding text. The named buffers are specified by the alphanumeric characters of the POSIX locale. There shall also be one "unnamed" buffer. When no buffer is specified for editor commands that use a buffer, the unnamed buffer shall be used. Commands that store text into buffers shall store the text as it was before the command took effect, and shall store text occurring earlier in the file before text occurring later in the file, regardless of how the text region was specified. Commands that store text into buffers shall store the text into the unnamed buffer as well as any specified buffer.

In ex commands, buffer names are specified as the name by itself. In open or visual mode commands the name is preceded by a double quote ( ' )' character.

If the specified buffer name is an uppercase character, and the buffer contents are to be modified, the buffer shall be appended to rather than being overwritten. If the buffer is not being modified, specifying the buffer name in lowercase and uppercase shall have identical results.

There shall also be buffers named by the numbers 1 through 9. In open and visual mode, if a region of text including characters from more than a single line is being modified by the vi c or d commands, the motion character associated with the c or d commands specifies that the buffer text shall be in line mode, or the commands %, `, /, ?, (, ), N, n, {, or } are used to define a region of text for the c or d commands, the contents of buffers 1 through 8 shall be moved into the buffer named by the next numerically greater value, the contents of buffer 9 shall be discarded, and the region of text shall be copied into buffer 1. This shall be in addition to copying the text into a user-specified buffer or unnamed buffer, or both. Numeric buffers can be specified as a source buffer for open and visual mode commands; however, specifying a numeric buffer as the write target of an open or visual mode command shall have unspecified results.

The text of each buffer shall have the characteristic of being in either line or character mode. Appending text to a non-empty buffer shall set the mode to match the characteristic of the text being appended. Appending text to a buffer shall cause the creation of at least one additional line in the buffer. All text stored into buffers by ex commands shall be in line mode. The ex commands that use buffers as the source of text specify individually how buffers of different modes are handled. Each open or visual mode command that uses buffers for any purpose specifies individually the mode of the text stored into the buffer and how buffers of different modes are handled.

file

Command text used to derive a pathname. The default shall be the current pathname, as defined previously, in which case, if no current pathname has yet been established it shall be an error, except where specifically noted in the individual command descriptions that follow. If the command text contains any of the characters '˜', '{', '[', '*', '?', '$', '`', '", ' ,' and '\', it shall be subjected to the process of "shell expansions", as described below; if more than a single pathname results and the command expects only one, it shall be an error.

The process of shell expansions in the editor shall be done as follows. The ex utility shall pass two arguments to the program named by the shell edit option; the first shall be -c, and the second shall be the string "echo" and the command text as a single argument. The standard output and standard error of that command shall replace the command text.

!

A character that can be appended to the command name to modify its operation, as detailed in the individual command descriptions. With the exception of the ex read, write, and ! commands, the '!' character shall only act as a modifier if there are no <blank>s between it and the command name.

remembered search direction

The vi commands N and n begin searching in a forwards or backwards direction in the edit buffer based on a remembered search direction, which is initially unset, and is set by the ex global, v, s, and tag commands, and the vi / and ? commands.

Abbreviate

Synopsis:

ab[breviate][lhs rhs]

If lhs and rhs are not specified, write the current list of abbreviations and do nothing more.

Implementations may restrict the set of characters accepted in lhs or rhs, except that printable characters and <blank>s shall not be restricted. Additional restrictions shall be implementation-defined.

In both lhs and rhs, any character may be escaped with a <control>-V, in which case the character shall not be used to delimit lhs from rhs, and the escaping <control>-V shall be discarded.

In open and visual text input mode, if a non-word or <ESC> character that is not escaped by a <control>-V character is entered after a word character, a check shall be made for a set of characters matching lhs, in the text input entered during this command. If it is found, the effect shall be as if rhs was entered instead of lhs.

The set of characters that are checked is defined as follows:

1. If there are no characters inserted before the word and non-word or <ESC> characters that triggered the check, the set of characters shall consist of the word character.

2. If the character inserted before the word and non-word or <ESC> characters that triggered the check is a word character, the set of characters shall consist of the characters inserted immediately before the triggering characters that are word characters, plus the triggering word character.

3. If the character inserted before the word and non-word or <ESC> characters that triggered the check is not a word character, the set of characters shall consist of the characters that were inserted before the triggering characters that are neither <blank>s nor word characters, plus the triggering word character.

It is unspecified whether the lhs argument entered for the ex abbreviate and unabbreviate commands is replaced in this fashion. Regardless of whether or not the replacement occurs, the effect of the command shall be as if the replacement had not occurred.

Current line: Unchanged.

Current column: Unchanged.

Append

Synopsis:

[1addr] a[ppend][!]

Enter ex text input mode; the input text shall be placed after the specified line. If line zero is specified, the text shall be placed at the beginning of the edit buffer.

This command shall be affected by the number and autoindent edit options; following the command name with '!' shall cause the autoindent edit option setting to be toggled for the duration of this command only.

Current line: Set to the last input line; if no lines were input, set to the specified line, or to the first line of the edit buffer if a line of zero was specified, or zero if the edit buffer is empty.

Current column: Set to non- <blank>.

Arguments

Synopsis:

ar[gs]

Write the current argument list, with the current argument-list entry, if any, between '[' and ']' characters.

Current line: Unchanged.

Current column: Unchanged.

Change

Synopsis:

[2addr] c[hange][!][count]

Enter ex text input mode; the input text shall replace the specified lines. The specified lines shall be copied into the unnamed buffer, which shall become a line mode buffer.

This command shall be affected by the number and autoindent edit options; following the command name with '!' shall cause the autoindent edit option setting to be toggled for the duration of this command only.

Current line: Set to the last input line; if no lines were input, set to the line before the first address, or to the first line of the edit buffer if there are no lines preceding the first address, or to zero if the edit buffer is empty.

Current column: Set to non- <blank>.

Change Directory

Synopsis:

chd[ir][!][directory]cd[!][directory]

Change the current working directory to directory.

If no directory argument is specified, and the HOME environment variable is set to a non-null and non-empty value, directory shall default to the value named in the HOME environment variable. If the HOME environment variable is empty or is undefined, the default value of directory is implementation-defined.

If no '!' is appended to the command name, and the edit buffer has been modified since the last complete write, and the current pathname does not begin with a '/', it shall be an error.

Current line: Unchanged.

Current column: Unchanged.

Copy

Synopsis:

[2addr] co[py] 1addr [flags]
[2addr] t 1addr [flags]

Copy the specified lines after the specified destination line; line zero specifies that the lines shall be placed at the beginning of the edit buffer.

Current line: Set to the last line copied.

Current column: Set to non- <blank>.

Delete

Synopsis:

[2addr] d[elete][buffer][count][flags]

Delete the specified lines into a buffer (defaulting to the unnamed buffer), which shall become a line-mode buffer.

Flags can immediately follow the command name; see Command Line Parsing in ex.

Current line: Set to the line following the deleted lines, or to the last line in the edit buffer if that line is past the end of the edit buffer, or to zero if the edit buffer is empty.

Current column: Set to non- <blank>.

Edit

Synopsis:

e[dit][!][+command][file]ex[!][+command][file]

If no '!' is appended to the command name, and the edit buffer has been modified since the last complete write, it shall be an error.

If file is specified, replace the current contents of the edit buffer with the current contents of file, and set the current pathname to file. If file is not specified, replace the current contents of the edit buffer with the current contents of the file named by the current pathname. If for any reason the current contents of the file cannot be accessed, the edit buffer shall be empty.

The + command option shall be <blank>-delimited; <blank>s within + command can be escaped by preceding them with a backslash character. The + command shall be interpreted as an ex command immediately after the contents of the edit buffer have been replaced and the current line and column have been set.

If the edit buffer is empty:

Current line: Set to 0.

Current column: Set to 1.

Otherwise, if executed while in ex command mode or if the + command argument is specified:

Current line: Set to the last line of the edit buffer.

Current column: Set to non- <blank>.

Otherwise, if file is omitted or results in the current pathname:

Current line: Set to the first line of the edit buffer.

Current column: Set to non- <blank>.

Otherwise, if file is the same as the last file edited, the line and column shall be set as follows; if the file was previously edited, the line and column may be set as follows:

Current line: Set to the last value held when that file was last edited. If this value is not a valid line in the new edit buffer, set to the first line of the edit buffer.

Current column: If the current line was set to the last value held when the file was last edited, set to the last value held when the file was last edited. Otherwise, or if the last value is not a valid column in the new edit buffer, set to non- <blank>.

Otherwise:

Current line: Set to the first line of the edit buffer.

Current column: Set to non- <blank>.

File

Synopsis:

f[ile][file]

If a file argument is specified, the alternate pathname shall be set to the current pathname, and the current pathname shall be set to file.

Write an informational message. If the file has a current pathname, it shall be included in this message; otherwise, the message shall indicate that there is no current pathname. If the edit buffer contains lines, the current line number and the number of lines in the edit buffer shall be included in this message; otherwise, the message shall indicate that the edit buffer is empty. If the edit buffer has been modified since the last complete write, this fact shall be included in this message. If the readonly edit option is set, this fact shall be included in this message. The message may contain other unspecified information.

Current line: Unchanged.

Current column: Unchanged.

Global

Synopsis:

[2addr] g[lobal] /pattern/ [commands]
[2addr] v /pattern/ [commands]

The optional '!' character after the global command shall be the same as executing the v command.

If pattern is empty (for example, "//" ) or not specified, the last regular expression used in the editor command shall be used as the pattern. The pattern can be delimited by slashes (shown in the Synopsis), as well as any non-alphanumeric or non- <blank> other than backslash, vertical line, double quote, or <newline>.

If no lines are specified, the lines shall default to the entire file.

The global and v commands are logically two-pass operations. First, mark the lines within the specified lines for which the line excluding the terminating <newline> matches ( global) or does not match ( v or global!) the specified pattern. Second, execute the ex commands given by commands, with the current line ( '.' ) set to each marked line. If an error occurs during this process, or the contents of the edit buffer are replaced (for example, by the ex :edit command) an error message shall be written and no more commands resulting from the execution of this command shall be processed.

Multiple ex commands can be specified by entering multiple commands on a single line using a vertical line to delimit them, or one per line, by escaping each <newline> with a backslash.

If no commands are specified:

1. If in ex command mode, it shall be as if the print command were specified.

2. Otherwise, no command shall be executed.

For the append, change, and insert commands, the input text shall be included as part of the command, and the terminating period can be omitted if the command ends the list of commands. The open and visual commands can be specified as one of the commands, in which case each marked line shall cause the editor to enter open or visual mode. If open or visual mode is exited using the vi Q command, the current line shall be set to the next marked line, and open or visual mode reentered, until the list of marked lines is exhausted.

The global, v, and undo commands cannot be used in commands. Marked lines may be deleted by commands executed for lines occurring earlier in the file than the marked lines. In this case, no commands shall be executed for the deleted lines.

If the remembered search direction is not set, the global and v commands shall set it to forward.

The autoprint and autoindent edit options shall be inhibited for the duration of the g or v command.

Current line: If no commands executed, set to the last marked line. Otherwise, as specified for the executed ex commands.

Current column: If no commands are executed, set to non- <blank>; otherwise, as specified for the individual ex commands.

Insert

Synopsis:

[1addr] i[nsert][!]

Enter ex text input mode; the input text shall be placed before the specified line. If the line is zero or 1, the text shall be placed at the beginning of the edit buffer.

This command shall be affected by the number and autoindent edit options; following the command name with '!' shall cause the autoindent edit option setting to be toggled for the duration of this command only.

Current line: Set to the last input line; if no lines were input, set to the line before the specified line, or to the first line of the edit buffer if there are no lines preceding the specified line, or zero if the edit buffer is empty.

Current column: Set to non- <blank>.

Join

Synopsis:

[2addr] j[oin][!][count][flags]

If count is specified:

If no address was specified, the join command shall behave as if 2addr were the current line and the current line plus count (.,. + count).

If one address was specified, the join command shall behave as if 2addr were the specified address and the specified address plus count ( addr, addr + count).

If two addresses were specified, the join command shall behave as if an additional address, equal to the last address plus count -1 ( addr1, addr2, addr2 + count -1), was specified.

If this would result in a second address greater than the last line of the edit buffer, it shall be corrected to be equal to the last line of the edit buffer.

If no count is specified:

If no address was specified, the join command shall behave as if 2addr were the current line and the next line (.,. +1).

If one address was specified, the join command shall behave as if 2addr were the specified address and the next line ( addr, addr +1).

Join the text from the specified lines together into a single line, which shall replace the specified lines.

If a '!' character is appended to the command name, the join shall be without modification of any line, independent of the current locale.

Otherwise, in the POSIX locale, set the current line to the first of the specified lines, and then, for each subsequent line, proceed as follows:

1. Discard leading <space>s from the line to be joined.

2. If the line to be joined is now empty, delete it, and skip steps 3 through 5.

3. If the current line ends in a <blank>, or the first character of the line to be joined is a ')' character, join the lines without further modification.

4. If the last character of the current line is a '.', join the lines with two <space>s between them.

5. Otherwise, join the lines with a single <space> between them.

Current line: Set to the first line specified.

Current column: Set to non- <blank>.

List

Synopsis:

[2addr] l[ist][count][flags]

This command shall be equivalent to the ex command:

[2addr] p[rint][count] l[flags]

See Print.

Map

Synopsis:

map[!][lhs rhs]

If lhs and rhs are not specified:

1. If '!' is specified, write the current list of text input mode maps.

2. Otherwise, write the current list of command mode maps.

3. Do nothing more.

Implementations may restrict the set of characters accepted in lhs or rhs, except that printable characters and <blank>s shall not be restricted. Additional restrictions shall be implementation-defined. In both lhs and rhs, any character can be escaped with a <control>-V, in which case the character shall not be used to delimit lhs from rhs, and the escaping <control>-V shall be discarded.

If the character '!' is appended to the map command name, the mapping shall be effective during open or visual text input mode rather than open or visual command mode. This allows lhs to have two different map definitions at the same time: one for command mode and one for text input mode.

For command mode mappings:

When the lhs is entered as any part of a vi command in open or visual mode (but not as part of the arguments to the command), the action shall be as if the corresponding rhs had been entered.

If any character in the command, other than the first, is escaped using a <control>-V character, that character shall not be part of a match to an lhs.

It is unspecified whether implementations shall support map commands where the lhs is more than a single character in length, where the first character of the lhs is printable.

If lhs contains more than one character and the first character is '#', followed by a sequence of digits corresponding to a numbered function key, then when this function key is typed it shall be mapped to rhs. Characters other than digits following a '#' character also represent the function key named by the characters in the lhs following the '#' and may be mapped to rhs. It is unspecified how function keys are named or what function keys are supported.

For text input mode mappings:

When the lhs is entered as any part of text entered in open or visual text input modes, the action shall be as if the corresponding rhs had been entered.

If any character in the input text is escaped using a <control>-V character, that character shall not be part of a match to an lhs.

It is unspecified whether the lhs text entered for subsequent map or unmap commands is replaced with the rhs text for the purposes of the screen display; regardless of whether or not the display appears as if the corresponding rhs text was entered, the effect of the command shall be as if the lhs text was entered.

If only part of the lhs is entered, it is unspecified how long the editor will wait for additional, possibly matching characters before treating the already entered characters as not matching the lhs.

The rhs characters shall themselves be subject to remapping, unless otherwise specified by the remap edit option, except that if the characters in lhs occur as prefix characters in rhs, those characters shall not be remapped.

On block-mode terminals, the mapping need not occur immediately (for example, it may occur after the terminal transmits a group of characters to the system), but it shall achieve the same results as if it occurred immediately.

Current line: Unchanged.

Current column: Unchanged.

Mark

Synopsis:

[1addr] ma[rk] character
[1addr] k character

Implementations shall support character values of a single lowercase letter of the POSIX locale and the characters '`' and '" ; support of other characters is implementation-defined.

If executing the vi m command, set the specified mark to the current line and 1-based numbered character referenced by the current column, if any; otherwise, column position 1.

Otherwise, set the specified mark to the specified line and 1-based numbered first non- <blank> non- <newline> in the line, if any; otherwise, the last non- <newline> in the line, if any; otherwise, column position 1.

The mark shall remain associated with the line until the mark is reset or the line is deleted. If a deleted line is restored by a subsequent undo command, any marks previously associated with the line, which have not been reset, shall be restored as well. Any use of a mark not associated with a current line in the edit buffer shall be an error.

The marks ` and ' shall be set as described previously, immediately before the following events occur in the editor:

1. The use of '$' as an ex address

2. The use of a positive decimal number as an ex address

3. The use of a search command as an ex address

4. The use of a mark reference as an ex address

5. The use of the following open and visual mode commands: <control>-], %, (, ), [, ], {, }

6. The use of the following open and visual mode commands: ', G, H, L, M, z if the current line will change as a result of the command

7. The use of the open and visual mode commands: /, ?, N, `, n if the current line or column will change as a result of the command

8. The use of the ex mode commands: z, undo, global, v

For rules 1., 2., 3., and 4., the ` and ' marks shall not be set if the ex command is parsed as specified by rule 6.a. in Command Line Parsing in ex.

For rules 5., 6., and 7., the ` and ' marks shall not be set if the commands are used as motion commands in open and visual mode.

For rules 1., 2., 3., 4., 5., 6., 7., and 8., the ` and ' marks shall not be set if the command fails.

The ` and ' marks shall be set as described previously, each time the contents of the edit buffer are replaced (including the editing of the initial buffer), if in open or visual mode, or if in ex mode and the edit buffer is not empty, before any commands or movements (including commands or movements specified by the -c or -t options or the + command argument) are executed on the edit buffer. If in open or visual mode, the marks shall be set as if executing the vi m command; otherwise, as if executing the ex mark command.

When changing from ex mode to open or visual mode, if the ` and ' marks are not already set, the ` and ' marks shall be set as described previously.

Current line: Unchanged.

Current column: Unchanged.

Move

Synopsis:

[2addr] m[ove] 1addr [flags]

Move the specified lines after the specified destination line. A destination of line zero specifies that the lines shall be placed at the beginning of the edit buffer. It shall be an error if the destination line is within the range of lines to be moved.

Current line: Set to the last of the moved lines.

Current column: Set to non- <blank>.

Next

Synopsis:

n[ext][!][+command][file ...]

If no '!' is appended to the command name, and the edit buffer has been modified since the last complete write, it shall be an error, unless the file is successfully written as specified by the autowrite option.

If one or more files is specified:

1. Set the argument list to the specified filenames.

2. Set the current argument list reference to be the first entry in the argument list.

3. Set the current pathname to the first filename specified.

Otherwise:

1. It shall be an error if there are no more filenames in the argument list after the filename currently referenced.

2. Set the current pathname and the current argument list reference to the filename after the filename currently referenced in the argument list.

Replace the contents of the edit buffer with the contents of the file named by the current pathname. If for any reason the contents of the file cannot be accessed, the edit buffer shall be empty.

This command shall be affected by the autowrite and writeany edit options.

The + command option shall be <blank>-delimited; <blank>s can be escaped by preceding them with a backslash character. The + command shall be interpreted as an ex command immediately after the contents of the edit buffer have been replaced and the current line and column have been set.

Current line: Set as described for the edit command.

Current column: Set as described for the edit command.

Number

Synopsis:

[2addr] nu[mber][count][flags]
[2addr] #[count][flags]

These commands shall be equivalent to the ex command:

[2addr] p[rint][count] #[flags]

See Print.

Open

Synopsis:

[1addr] o[pen] /pattern/ [flags]

This command need not be supported on block-mode terminals or terminals with insufficient capabilities. If standard input, standard output, or standard error are not terminal devices, the results are unspecified.

Enter open mode.

The trailing delimiter can be omitted from pattern at the end of the command line. If pattern is empty (for example, "//" ) or not specified, the last regular expression used in the editor shall be used as the pattern. The pattern can be delimited by slashes (shown in the Synopsis), as well as any alphanumeric, or non- <blank> other than backslash, vertical line, double quote, or <newline>.

Current line: Set to the specified line.

Current column: Set to non- <blank>.

Preserve

Synopsis:

pre[serve]

Save the edit buffer in a form that can later be recovered by using the -r option or by using the ex recover command. After the file has been preserved, a mail message shall be sent to the user. This message shall be readable by invoking the mailx utility. The message shall contain the name of the file, the time of preservation, and an ex command that could be used to recover the file. Additional information may be included in the mail message.

Current line: Unchanged.

Current column: Unchanged.

Print

Synopsis:

[2addr] p[rint][count][flags]

Write the addressed lines. The behavior is unspecified if the number of columns on the display is less than the number of columns required to write any single character in the lines being written.

Non-printable characters, except for the <tab>, shall be written as implementation-defined multi-character sequences.

If the # flag is specified or the number edit option is set, each line shall be preceded by its line number in the following format:

"%6d", <line number>

If the l flag is specified or the list edit option is set:

1. The characters listed in the Base Definitions volume of IEEE Std 1003.1-2001, Table 5-1, Escape Sequences and Associated Actions shall be written as the corresponding escape sequence.

2. Non-printable characters not in the Base Definitions volume of IEEE Std 1003.1-2001, Table 5-1, Escape Sequences and Associated Actions shall be written as one three-digit octal number (with a preceding backslash) for each byte in the character (most significant byte first).

3. The end of each line shall be marked with a '$', and literal '$' characters within the line shall be written with a preceding backslash.

Long lines shall be folded; the length at which folding occurs is unspecified, but should be appropriate for the output terminal, considering the number of columns of the terminal.

If a line is folded, and the l flag is not specified and the list edit option is not set, it is unspecified whether a multi-column character at the folding position is separated; it shall not be discarded.

Current line: Set to the last written line.

Current column: Unchanged if the current line is unchanged; otherwise, set to non- <blank>.

Put

Synopsis:

[1addr] pu[t][buffer]

Append text from the specified buffer (by default, the unnamed buffer) to the specified line; line zero specifies that the text shall be placed at the beginning of the edit buffer. Each portion of a line in the buffer shall become a new line in the edit buffer, regardless of the mode of the buffer.

Current line: Set to the last line entered into the edit buffer.

Current column: Set to non- <blank>.

Quit

Synopsis:

q[uit][!]

If no '!' is appended to the command name:

1. If the edit buffer has been modified since the last complete write, it shall be an error.

2. If there are filenames in the argument list after the filename currently referenced, and the last command was not a quit, wq, xit, or ZZ (see Exit) command, it shall be an error.

Otherwise, terminate the editing session.

Read

Synopsis:

[1addr] r[ead][!][file]

If '!' is not the first non- <blank> to follow the command name, a copy of the specified file shall be appended into the edit buffer after the specified line; line zero specifies that the copy shall be placed at the beginning of the edit buffer. The number of lines and bytes read shall be written. If no file is named, the current pathname shall be the default. If there is no current pathname, then file shall become the current pathname. If there is no current pathname or file operand, it shall be an error. Specifying a file that is not of type regular shall have unspecified results.

Otherwise, if file is preceded by '!', the rest of the line after the '!' shall have '%', '#', and '!' characters expanded as described in Command Line Parsing in ex.

The ex utility shall then pass two arguments to the program named by the shell edit option; the first shall be -c and the second shall be the expanded arguments to the read command as a single argument. The standard input of the program shall be set to the standard input of the ex program when it was invoked. The standard error and standard output of the program shall be appended into the edit buffer after the specified line.

Each line in the copied file or program output (as delimited by <newline>s or the end of the file or output if it is not immediately preceded by a <newline>), shall be a separate line in the edit buffer. Any occurrences of <carriage-return> and <newline> pairs in the output shall be treated as single <newline>s.

The special meaning of the '!' following the read command can be overridden by escaping it with a backslash character.

Current line: If no lines are added to the edit buffer, unchanged. Otherwise, if in open or visual mode, set to the first line entered into the edit buffer. Otherwise, set to the last line entered into the edit buffer.

Current column: Set to non- <blank>.

Recover

Synopsis:

rec[over][!] file

If no '!' is appended to the command name, and the edit buffer has been modified since the last complete write, it shall be an error.

If no file operand is specified, then the current pathname shall be used. If there is no current pathname or file operand, it shall be an error.

If no recovery information has previously been saved about file, the recover command shall behave identically to the edit command, and an informational message to this effect shall be written.

Otherwise, set the current pathname to file, and replace the current contents of the edit buffer with the recovered contents of file. If there are multiple instances of the file to be recovered, the one most recently saved shall be recovered, and an informational message that there are previous versions of the file that can be recovered shall be written. The editor shall behave as if the contents of the edit buffer have already been modified.

Current file: Set as described for the edit command.

Current column: Set as described for the edit command.

Rewind

Synopsis:

rew[ind][!]

If no '!' is appended to the command name, and the edit buffer has been modified since the last complete write, it shall be an error, unless the file is successfully written as specified by the autowrite option.

If the argument list is empty, it shall be an error.

The current argument list reference and the current pathname shall be set to the first filename in the argument list.

Replace the contents of the edit buffer with the contents of the file named by the current pathname. If for any reason the contents of the file cannot be accessed, the edit buffer shall be empty.

This command shall be affected by the autowrite and writeany edit options.

Current line: Set as described for the edit command.

Current column: Set as described for the edit command.

Set

Synopsis:

se[t][option[=[value]] ...][nooption ...][option? ...][all]

When no arguments are specified, write the value of the term edit option and those options whose values have been changed from the default settings; when the argument all is specified, write all of the option values.

Giving an option name followed by the character '?' shall cause the current value of that option to be written. The '?' can be separated from the option name by zero or more <blank>s. The '?' shall be necessary only for Boolean valued options. Boolean options can be given values by the form set option to turn them on or set no option to turn them off; string and numeric options can be assigned by the form set option= value. Any <blank>s in strings can be included as is by preceding each <blank> with an escaping backslash. More than one option can be set or listed by a single set command by specifying multiple arguments, each separated from the next by one or more <blank>s.

See Edit Options in ex for details about specific options.

Current line: Unchanged.

Current column: Unchanged.

Shell

Synopsis:

sh[ell]

Invoke the program named in the shell edit option with the single argument -i (interactive mode). Editing shall be resumed when the program exits.

Current line: Unchanged.

Current column: Unchanged.

Source

Synopsis:

so[urce] file

Read and execute ex commands from file. Lines in the file that are blank lines shall be ignored.

Current line: As specified for the individual ex commands.

Current column: As specified for the individual ex commands.

Substitute

Synopsis:

[2addr] s[ubstitute][/pattern/repl/[options][count][flags]]

[2addr] &[options][count][flags]]

[2addr] ˜[options][count][flags]]

Replace the first instance of the pattern pattern by the string repl on each specified line. (See Regular Expressions in ex and Replacement Strings in ex.) Any non-alphabetic, non- <blank> delimiter other than '\', '|', double quote, or <newline> can be used instead of '/'. Backslash characters can be used to escape delimiters, backslash characters, and other special characters.

The trailing delimiter can be omitted from pattern or from repl at the end of the command line. If both pattern and repl are not specified or are empty (for example, "//" ), the last s command shall be repeated. If only pattern is not specified or is empty, the last regular expression used in the editor shall be used as the pattern. If only repl is not specified or is empty, the pattern shall be replaced by nothing. If the entire replacement pattern is '%', the last replacement pattern to an s command shall be used.

Entering a <carriage-return> in repl (which requires an escaping backslash in ex mode and an escaping <control>-V in open or vi mode) shall split the line at that point, creating a new line in the edit buffer. The <carriage-return> shall be discarded.

If options includes the letter 'g' ( global), all non-overlapping instances of the pattern in the line shall be replaced.

If options includes the letter 'c' ( confirm), then before each substitution the line shall be written; the written line shall reflect all previous substitutions. On the following line, <space>s shall be written beneath the characters from the line that are before the pattern to be replaced, and '^' characters written beneath the characters included in the pattern to be replaced. The ex utility shall then wait for a response from the user. An affirmative response shall cause the substitution to be done, while any other input shall not make the substitution. An affirmative response shall consist of a line with the affirmative response (as defined by the current locale) at the beginning of the line. This line shall be subject to editing in the same way as the ex command line.

If interrupted (see the ASYNCHRONOUS EVENTS section), any modifications confirmed by the user shall be preserved in the edit buffer after the interrupt.

If the remembered search direction is not set, the s command shall set it to forward.

In the second Synopsis, the & command shall repeat the previous substitution, as if the & command were replaced by:

s/pattern/repl/

where pattern and repl are as specified in the previous s, &, or ˜ command.

In the third Synopsis, the ˜ command shall repeat the previous substitution, as if the '˜' were replaced by:

s/pattern/repl/

where pattern shall be the last regular expression specified to the editor, and repl shall be from the previous substitution (including & and ˜) command.

These commands shall be affected by the LC_MESSAGES environment variable.

Current line: Set to the last line in which a substitution occurred, or, unchanged if no substitution occurred.

Current column: Set to non- <blank>.

Suspend

Synopsis:

su[spend][!]st[op][!]

Allow control to return to the invoking process; ex shall suspend itself as if it had received the SIGTSTP signal. The suspension shall occur only if job control is enabled in the invoking shell (see the description of set -m).

These commands shall be affected by the autowrite and writeany edit options.

The current susp character (see stty) shall be equivalent to the suspend command.

Tag

Synopsis:

ta[g][!] tagstring

The results are unspecified if the format of a tags file is not as specified by the ctags utility (see ctags) description.

The tag command shall search for tagstring in the tag files referred to by the tag edit option, in the order they are specified, until a reference to tagstring is found. Files shall be searched from beginning to end. If no reference is found, it shall be an error and an error message to this effect shall be written. If the reference is not found, or if an error occurs while processing a file referred to in the tag edit option, it shall be an error, and an error message shall be written at the first occurrence of such an error.

Otherwise, if the tags file contained a pattern, the pattern shall be treated as a regular expression used in the editor; for example, for the purposes of the s command.

If the tagstring is in a file with a different name than the current pathname, set the current pathname to the name of that file, and replace the contents of the edit buffer with the contents of that file. In this case, if no '!' is appended to the command name, and the edit buffer has been modified since the last complete write, it shall be an error, unless the file is successfully written as specified by the autowrite option.

This command shall be affected by the autowrite, tag, taglength, and writeany edit options.

Current line: If the tags file contained a line number, set to that line number. If the line number is larger than the last line in the edit buffer, an error message shall be written and the current line shall be set as specified for the edit command.

If the tags file contained a pattern, set to the first occurrence of the pattern in the file. If no matching pattern is found, an error message shall be written and the current line shall be set as specified for the edit command.

Current column: If the tags file contained a line-number reference and that line-number was not larger than the last line in the edit buffer, or if the tags file contained a pattern and that pattern was found, set to non- <blank>. Otherwise, set as specified for the edit command.

Unabbreviate

Synopsis:

una[bbrev] lhs

If lhs is not an entry in the current list of abbreviations (see Abbreviate), it shall be an error. Otherwise, delete lhs from the list of abbreviations.

Current line: Unchanged.

Current column: Unchanged.

Undo

Synopsis:

u[ndo]

Reverse the changes made by the last command that modified the contents of the edit buffer, including undo. For this purpose, the global, v, open, and visual commands, and commands resulting from buffer executions and mapped character expansions, are considered single commands.

If no action that can be undone preceded the undo command, it shall be an error.

If the undo command restores lines that were marked, the mark shall also be restored unless it was reset subsequent to the deletion of the lines.

Current line:

1. If lines are added or changed in the file, set to the first line added or changed.

2. Set to the line before the first line deleted, if it exists.

3. Set to 1 if the edit buffer is not empty.

4. Set to zero.

Current column: Set to non- <blank>.

Unmap

Synopsis:

unm[ap][!] lhs

If '!' is appended to the command name, and if lhs is not an entry in the list of text input mode map definitions, it shall be an error. Otherwise, delete lhs from the list of text input mode map definitions.

If no '!' is appended to the command name, and if lhs is not an entry in the list of command mode map definitions, it shall be an error. Otherwise, delete lhs from the list of command mode map definitions.

Current line: Unchanged.

Current column: Unchanged.

Version

Synopsis:

ve[rsion]

Write a message containing version information for the editor. The format of the message is unspecified.

Current line: Unchanged.

Current column: Unchanged.

Visual

Synopsis:

[1addr] vi[sual][type][count][flags]

If ex is currently in open or visual mode, the Synopsis and behavior of the visual command shall be the same as the edit command, as specified by Edit.

Otherwise, this command need not be supported on block-mode terminals or terminals with insufficient capabilities. If standard input, standard output, or standard error are not terminal devices, the results are unspecified.

If count is specified, the value of the window edit option shall be set to count (as described in window). If the '^' type character was also specified, the window edit option shall be set before being used by the type character.

Enter visual mode. If type is not specified, it shall be as if a type of '+' was specified. The type shall cause the following effects:

+

Place the beginning of the specified line at the top of the display.

-

Place the end of the specified line at the bottom of the display.

.

Place the beginning of the specified line in the middle of the display.

^

If the specified line is less than or equal to the value of the window edit option, set the line to 1; otherwise, decrement the line by the value of the window edit option minus 1. Place the beginning of this line as close to the bottom of the displayed lines as possible, while still displaying the value of the window edit option number of lines.

Current line: Set to the specified line.

Current column: Set to non- <blank>.

Write

Synopsis:

[2addr] w[rite][!][>>][file]
[2addr] w[rite][!][file]
[2addr] wq[!][>>][file]

If no lines are specified, the lines shall default to the entire file.

The command wq shall be equivalent to a write command followed by a quit command; wq! shall be equivalent to write! followed by quit. In both cases, if the write command fails, the quit shall not be attempted.

If the command name is not followed by one or more <blank>s, or file is not preceded by a '!' character, the write shall be to a file.

1. If the >> argument is specified, and the file already exists, the lines shall be appended to the file instead of replacing its contents. If the >> argument is specified, and the file does not already exist, it is unspecified whether the write shall proceed as if the >> argument had not been specified or if the write shall fail.

2. If the readonly edit option is set (see readonly), the write shall fail.

3. If file is specified, and is not the current pathname, and the file exists, the write shall fail.

4. If file is not specified, the current pathname shall be used. If there is no current pathname, the write command shall fail.

5. If the current pathname is used, and the current pathname has been changed by the file or read commands, and the file exists, the write shall fail. If the write is successful, subsequent writes shall not fail for this reason (unless the current pathname is changed again).

6. If the whole edit buffer is not being written, and the file to be written exists, the write shall fail.

For rules 1., 2., 4., and 5., the write can be forced by appending the character '!' to the command name.

For rules 2., 4., and 5., the write can be forced by setting the writeany edit option.

Additional, implementation-defined tests may cause the write to fail.

If the edit buffer is empty, a file without any contents shall be written.

An informational message shall be written noting the number of lines and bytes written.

Otherwise, if the command is followed by one or more <blank>s, and the file is preceded by '!', the rest of the line after the '!' shall have '%', '#', and '!' characters expanded as described in Command Line Parsing in ex.

The ex utility shall then pass two arguments to the program named by the shell edit option; the first shall be -c and the second shall be the expanded arguments to the write command as a single argument. The specified lines shall be written to the standard input of the command. The standard error and standard output of the program, if any, shall be written as described for the print command. If the last character in that output is not a <newline>, a <newline> shall be written at the end of the output.

The special meaning of the '!' following the write command can be overridden by escaping it with a backslash character.

Current line: Unchanged.

Current column: Unchanged.

Write and Exit

Synopsis:

[2addr] x[it][!][file]

If the edit buffer has not been modified since the last complete write, xit shall be equivalent to the quit command, or if a '!' is appended to the command name, to quit!.

Otherwise, xit shall be equivalent to the wq command, or if a '!' is appended to the command name, to wq!.

Current line: Unchanged.

Current column: Unchanged.

Yank

Synopsis:

[2addr] ya[nk][buffer][count]

Copy the specified lines to the specified buffer (by default, the unnamed buffer), which shall become a line-mode buffer.

Current line: Unchanged.

Current column: Unchanged.

Adjust Window

Synopsis:

[1addr] z[!][type ...][count][flags]

If no line is specified, the current line shall be the default; if type is omitted as well, the current line value shall first be incremented by 1. If incrementing the current line would cause it to be greater than the last line in the edit buffer, it shall be an error.

If there are <blank>s between the type argument and the preceding z command name or optional '!' character, it shall be an error.

If count is specified, the value of the window edit option shall be set to count (as described in window). If count is omitted, it shall default to 2 times the value of the scroll edit option, or if ! was specified, the number of lines in the display minus 1.

If type is omitted, then count lines starting with the specified line shall be written. Otherwise, count lines starting with the line specified by the type argument shall be written.

The type argument shall change the lines to be written. The possible values of type are as follows:

-

The specified line shall be decremented by the following value:

(((number of "-" characters) x count) -1)

If the calculation would result in a number less than 1, it shall be an error. Write lines from the edit buffer, starting at the new value of line, until count lines or the last line in the edit buffer has been written.

+

The specified line shall be incremented by the following value:

(((number of "+" characters) -1) x count) +1

If the calculation would result in a number greater than the last line in the edit buffer, it shall be an error. Write lines from the edit buffer, starting at the new value of line, until count lines or the last line in the edit buffer has been written.

=,.

If more than a single '.' or '=' is specified, it shall be an error. The following steps shall be taken:

1. If count is zero, nothing shall be written.

2. Write as many of the N lines before the current line in the edit buffer as exist. If count or '!' was specified, N shall be:

   (count -1) /2
   
   

   Otherwise, N shall be:

   (count -3) /2
   
   

   If N is a number less than 3, no lines shall be written.

3. If '=' was specified as the type character, write a line consisting of the smaller of the number of columns in the display divided by two, or 40 '-' characters.

4. Write the current line.

5. Repeat step 3.

6. Write as many of the N lines after the current line in the edit buffer as exist. N shall be defined as in step 2. If N is a number less than 3, no lines shall be written. If count is less than 3, no lines shall be written.

^

The specified line shall be decremented by the following value:

(((number of "^" characters) +1) x count) -1

If the calculation would result in a number less than 1, it shall be an error. Write lines from the edit buffer, starting at the new value of line, until count lines or the last line in the edit buffer has been written.

Current line: Set to the last line written, unless the type is =, in which case, set to the specified line.

Current column: Set to non- <blank>.

Escape

Synopsis:

! command
[addr]! command

The contents of the line after the '!' shall have '%', '#', and '!' characters expanded as described in Command Line Parsing in ex. If the expansion causes the text of the line to change, it shall be redisplayed, preceded by a single '!' character.

The ex utility shall execute the program named by the shell edit option. It shall pass two arguments to the program; the first shall be -c, and the second shall be the expanded arguments to the ! command as a single argument.

If no lines are specified, the standard input, standard output, and standard error of the program shall be set to the standard input, standard output, and standard error of the ex program when it was invoked. In addition, a warning message shall be written if the edit buffer has been modified since the last complete write, and the warn edit option is set.

If lines are specified, they shall be passed to the program as standard input, and the standard output and standard error of the program shall replace those lines in the edit buffer. Each line in the program output (as delimited by <newline>s or the end of the output if it is not immediately preceded by a <newline>), shall be a separate line in the edit buffer. Any occurrences of <carriage-return> and <newline> pairs in the output shall be treated as single <newline>s. The specified lines shall be copied into the unnamed buffer before they are replaced, and the unnamed buffer shall become a line-mode buffer.

If in ex mode, a single '!' character shall be written when the program completes.

This command shall be affected by the shell and warn edit options. If no lines are specified, this command shall be affected by the autowrite and writeany edit options. If lines are specified, this command shall be affected by the autoprint edit option.

Current line:

1. If no lines are specified, unchanged.

2. Otherwise, set to the last line read in, if any lines are read in.

3. Otherwise, set to the line before the first line of the lines specified, if that line exists.

4. Otherwise, set to the first line of the edit buffer if the edit buffer is not empty.

5. Otherwise, set to zero.

Current column: If no lines are specified, unchanged. Otherwise, set to non- <blank>.

Shift Left

Synopsis:

[2addr] <[< ...][count][flags]

Shift the specified lines to the start of the line; the number of column positions to be shifted shall be the number of command characters times the value of the shiftwidth edit option. Only leading <blank>s shall be deleted or changed into other <blank>s in shifting; other characters shall not be affected.

Lines to be shifted shall be copied into the unnamed buffer, which shall become a line-mode buffer.

This command shall be affected by the autoprint edit option.

Current line: Set to the last line in the lines specified.

Current column: Set to non- <blank>.

Shift Right

Synopsis:

[2addr] >[> ...][count][flags]

Shift the specified lines away from the start of the line; the number of column positions to be shifted shall be the number of command characters times the value of the shiftwidth edit option. The shift shall be accomplished by adding <blank>s as a prefix to the line or changing leading <blank>s into other <blank>s. Empty lines shall not be changed.

Lines to be shifted shall be copied into the unnamed buffer, which shall become a line-mode buffer.

This command shall be affected by the autoprint edit option.

Current line: Set to the last line in the lines specified.

Current column: Set to non- <blank>.

<control>-D

Synopsis:

<control>-D

Write the next n lines, where n is the minimum of the values of the scroll edit option and the number of lines after the current line in the edit buffer. If the current line is the last line of the edit buffer it shall be an error.

Current line: Set to the last line written.

Current column: Set to non- <blank>.

Write Line Number

Synopsis:

[1addr] = [flags]

If line is not specified, it shall default to the last line in the edit buffer. Write the line number of the specified line.

Current line: Unchanged.

Current column: Unchanged.

Execute

Synopsis:

[2addr] @ buffer[2addr] * buffer

If no buffer is specified or is specified as '@' or '*', the last buffer executed shall be used. If no previous buffer has been executed, it shall be an error.

For each line specified by the addresses, set the current line ( '.' ) to the specified line, and execute the contents of the named buffer (as they were at the time the @ command was executed) as ex commands. For each line of a line-mode buffer, and all but the last line of a character-mode buffer, the ex command parser shall behave as if the line was terminated by a <newline>.

If an error occurs during this process, or a line specified by the addresses does not exist when the current line would be set to it, or more than a single line was specified by the addresses, and the contents of the edit buffer are replaced (for example, by the ex :edit command) an error message shall be written, and no more commands resulting from the execution of this command shall be processed.

Current line: As specified for the individual e