CMD
Starts a new instance of the Windows XP command interpreter
CMD [/A | /U] [/Q] [/D] [/E:ON | /E:OFF] [/F:ON | /F:OFF] [/V:ON
| /V:OFF]
[[/S] [/C | /K] string]
/C Carries out the command specified by string and then
terminates
/K Carries out the command specified by string but remains
/S Modifies the treatment of string after /C or /K (see
below)
/Q Turns echo off
/D Disable execution of AutoRun commands from registry (see
below)
/A Causes the output of internal commands to a pipe or file
to be ANSI
/U Causes the output of internal commands to a pipe or file
to be
Unicode
/T:fg Sets the foreground/background colors (see COLOR /?
for more info)
/E:ON Enable command extensions (see below)
/E:OFF Disable command extensions (see below)
/F:ON Enable file and directory name completion characters
(see below)
/F:OFF Disable file and directory name completion characters
(see below)
/V:ON Enable delayed environment variable expansion using !
as the
delimiter. For example, /V:ON would allow !var! to expand
the
variable var at execution time. The var syntax expands
variables
at input time, which is quite a different thing when inside
of a FOR
loop.
/V:OFF Disable delayed environment expansion.
Note that multiple commands separated by the command
separator '&&'
are accepted for string if surrounded by quotes. Also, for
compatibility
reasons, /X is the same as /E:ON, /Y is the same as /E:OFF
and /R is the
same as /C. Any other switches are ignored.
If /C or /K is specified, then the remainder of the command
line after
the switch is processed as a command line, where the
following logic is
used to process quote (") characters:
1. If all of the following conditions are met, then quote
characters
on the command line are preserved:
- no /S switch
- exactly two quote characters
- no special characters between the two quote characters,
where special is one of: &<>()@^|
- there are one or more whitespace characters between the
the two quote characters
- the string between the two quote characters is the name
of an executable file.
2. Otherwise, old behavior is to see if the first character
is
a quote character and if so, strip the leading character and
remove the last quote character on the command line,
preserving
any text after the last quote character.
If /D was NOT specified on the command line, then when
CMD.EXE starts, it
looks for the following REG_SZ/REG_EXPAND_SZ registry
variables, and if
either or both are present, they are executed first.
HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\AutoRun
and/or
HKEY_CURRENT_USER\Software\Microsoft\Command Processor\AutoRun
Command Extensions are enabled by default. You may also
disable
extensions for a particular invocation by using the /E:OFF
switch. You
can enable or disable extensions for all invocations of
CMD.EXE on a
machine and/or user logon session by setting either or both
of the
following REG_DWORD values in the registry using
REGEDT32.EXE:
HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\EnableExtensions
and/or
HKEY_CURRENT_USER\Software\Microsoft\Command Processor\EnableExtensions
to either 0x1 or 0x0. The user specific setting takes
precedence over
the machine setting. The command line switches take
precedence over the
registry settings.
The command extensions involve changes and/or additions to
the following
commands:
DEL or ERASE
COLOR
CD or CHDIR
MD or MKDIR
PROMPT
PUSHD
POPD
SET
SETLOCAL
ENDLOCAL
IF
FOR
CALL
SHIFT
GOTO
START (also includes changes to external command invocation)
ASSOC
FTYPE
To get specific details, type commandname /? to view the
specifics.
Delayed environment variable expansion is NOT enabled by
default. You
can enable or disable delayed environment variable expansion
for a
particular invocation of CMD.EXE with the /V:ON or /V:OFF
switch. You
can enable or disable completion for all invocations of
CMD.EXE on a
machine and/or user logon session by setting either or both
of the
following REG_DWORD values in the registry using
REGEDT32.EXE:
HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\DelayedExpansion
and/or
HKEY_CURRENT_USER\Software\Microsoft\Command Processor\DelayedExpansion
to either 0x1 or 0x0. The user specific setting takes
precedence over
the machine setting. The command line switches take
precedence over the
registry settings.
If delayed environment variable expansion is enabled, then
the exclamation
character can be used to substitute the value of an
environment variable
at execution time.
File and Directory name completion is NOT enabled by
default. You can
enable or disable file name completion for a particular
invocation of
CMD.EXE with the /F:ON or /F:OFF switch. You can enable or
disable
completion for all invocations of CMD.EXE on a machine
and/or user logon
session by setting either or both of the following REG_DWORD
values in
the registry using REGEDT32.EXE:
HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\CompletionChar
HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\PathCompletionChar
and/or
HKEY_CURRENT_USER\Software\Microsoft\Command Processor\CompletionChar
HKEY_CURRENT_USER\Software\Microsoft\Command Processor\PathCompletionChar
with the hex value of a control character to use for a
particular
function (e.g. 0x4 is Ctrl-D and 0x6 is Ctrl-F). The user
specific
settings take precedence over the machine settings. The
command line
switches take precedence over the registry settings.
If completion is enabled with the /F:ON switch, the two
control
characters used are Ctrl-D for directory name completion and
Ctrl-F for
file name completion. To disable a particular completion
character in
the registry, use the value for space (0x20) as it is not a
valid
control character.
Completion is invoked when you type either of the two
control
characters. The completion function takes the path string to
the left
of the cursor appends a wild card character to it if none is
already
present and builds up a list of paths that match. It then
displays the
first matching path. If no paths match, it just beeps and
leaves the
display alone. Thereafter, repeated pressing of the same
control
character will cycle through the list of matching paths.
Pressing the
Shift key with the control character will move through the
list
backwards. If you edit the line in any way and press the
control
character again, the saved list of matching paths is
discarded and a new
one generated. The same occurs if you switch between file
and directory
name completion. The only difference between the two control
characters
is the file completion character matches both file and
directory names,
while the directory completion character only matches
directory names.
If file completion is used on any of the built in directory
commands
(CD, MD or RD) then directory completion is assumed.
The completion code deals correctly with file names that
contain spaces
or other special characters by placing quotes around the
matching path.
Also, if you back up, then invoke completion from within a
line, the
text to the right of the cursor at the point completion was
invoked is
discarded.
The special characters that require quotes are:
<space>
&()[]{}^=;!'+,`~
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