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 exopen 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.
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
expreserve 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 -ttagstring 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.
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 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.
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
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 .
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 expreserve 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 exrecover
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.
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.
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 exedit,
ex, or recover commands, or if an extag command replaces the contents of the edit buffer.
a.
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.
b.
Otherwise, the alternate pathname shall be set to the file argument.
2.
If a file argument is specified to the exnext command:
a.
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 exfile 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 exread 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 exxit command:
a.
If the current pathname has no value, the current pathname shall be
set to the file argument.
b.
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:
a.
The HOME environment variable is not null and not empty.
b.
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:
a.
The current directory is not referred to by the HOME environment
variable.
b.
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.
c.
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 extag 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 exedit
command was entered with the first of those arguments as its file
argument.
3.
Otherwise, the effect shall be as if the exedit 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 exnext 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 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 exmark or k commands, or the vim 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.
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>:
a.
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.
b.
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 exnumber,
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.
c.
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:
a.
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.
b.
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’ .
c.
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:
a.
Any ’!’ character immediately following the command shall be
skipped and be part of the command.
b.
Any leading <blank>s shall be skipped and be part of the command.
c.
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.
d.
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:
a.
Any leading <blank>s shall be skipped and be part of the command.
b.
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.
c.
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.
d.
Otherwise, the rest of the command shall be determined by the steps
specified in paragraph 12.
12.
Otherwise:
a.
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.
b.
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.
c.
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.
d.
If the command was ended by a double-quote character, all subsequent
characters, up to the next non-backslash-escaped
<newline>, shall be discarded.
e.
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 exnext 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 exread
command, where the first non- <blank> after the
command name is a ’!’ character, or in the arguments to the
exwrite 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 exedit, 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.
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 exnumber
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.
See the description of the sttyeof 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.
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 exautoindent edit
option.
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.
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.
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.
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 vic
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 ’#146; , 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 exread, 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 exglobal, v, s, and tag commands, and the vi/ and
? commands.
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 rh, 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 exabbreviate 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.
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.
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.
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.
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.
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.
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.
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 viQ 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.
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.
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.
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.
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 vim 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 vim command; otherwise, as if executing the exmark
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.
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.
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.
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>.
