All these modifications have been verified with Windows' CMD, either
by using written cmd_rostests and the existing cmd_winetests, or
manually by enabling the flags cmd!fDumpTokens and cmd!fDumpParse
(available in the public symbols) and analyzing how the tokens are
being parsed, as well as the generated command tree.
See also the following links for more details (but remember that these
observations have to be double-checked in Windows' CMD!):
* Parser rules: https://stackoverflow.com/a/4095133/13530036
* Discussion: https://www.dostips.com/forum/viewtopic.php?f=3&t=8355
* Numbers parsing: https://www.dostips.com/forum/viewtopic.php?t=3758
* Label names vs. GOTO and CALL: https://www.dostips.com/forum/viewtopic.php?f=3&t=3803
and: https://www.dostips.com/forum/viewtopic.php?f=3&t=3803&p=55405#p55405
- Fix REM command parsing. A C_COMMAND-like structure should still
be built, so that it can show up during batch command echo. However
some specific handling needs to be done, so use instead a new C_REM
command type.
Escape carets are parsed differently than usual: they are explicitly
kept in the command line and don't participate in line continuations.
Also, the Windows' CMD behaviour is to discards everything before the
last line continuation.
- Prefix operator '@' (the "silent" operator) is parsed as a separate
command. Thus, the command @@foo@bar is parsed as: '@', '@', 'foo@bar'.
- Improve the checks for numbered redirection.
For this purpose, we check whether this is a number, that is in first
position in the current parsing buffer or is preceded by a whitespace-
like separator, including standard command operators (excepting '@' !)
and double-quotes.
- Empty command blocks, i.e. "( )", standing by themselves, or present
in IF or FOR commands, are considered invalid. (The closing parenthesis
is considered "unexpected".)
- Ignore single closing parenthesis when being outside of command blocks,
thus interpreting it as a command, and ignore explicitly everything
following on the same line, including line continuations.
This very specific situation can happen e.g. while running in batch mode,
when jumping to a label present inside a command block.
See the code for a thorough explanation.
- Detect whether a parenthesized block is not terminated at the end
of a command stream (getting a NUL character instead of a newline),
and if so, bail out early instead of entering into an infinite loop.
- Perform a similar check for the parenthesized list in FOR commands.
- Initialize the static 'InsideBlock' value to a known value.
- The '&' operator (multi-commmand) is allowed to have an empty RHS.
When such situation occurs, turn the CurrentTokenType to TOK_END
so as to avoid a parse error later on.
- The main body of a IF statement, or its 'else' clause, as well as
the main body of a FOR statement, must not be empty, otherwise this
is considered a syntax error. If so, call ParseError() that sets
the 'bParseError' flag, and forcing all batch execution to stop.
- First, the option and the APIs called by it can work directly on
paths relative to the current directory. So there is no need to
call GetFullPathName(), with the risk of going over MAX_PATH if the
current path is quite long (or nested) but the RMDIR is called on a
(short-length) relative sub-directory.
- Append a path-separator (backslash), only if the specified directory
does not have one already, and, that it does not specify a current
directory via the "drive-root" method, e.g. "C:" without any trailing
backslash.
- In case there are errors during deletion of sub-directories or
sub-files, print the error but continue deleting the other sub-dirs
or files.
- Monitor the Ctrl-C breaker as well, and stop deleting if it has been
triggered.
- When removing file/directory read-only attribute, just remove this
attribute, but keep the other ones.
- When deleting the directory, first try to do it directly; if it fails
with access denied, check whether it was read-only, and if so, remove
this attribute and retry deletion, otherwise fails.
- When recursively deleting a drive root directory, ultimately resolve
the dir pattern and check whether it's indeed a drive root, e.g.
"C:\\", and if so, just return success. Indeed, calling
RemoveDirectory() on such drive roots will return ERROR_ACCESS_DENIED
otherwise, but we want to succeed even if, of course, we won't
actually "delete" the drive root.
For MKDIR, also properly support the case of ERROR_FILE_EXISTS and
ERROR_ALREADY_EXISTS last-errors by displaying the standard error
"A subdirectory or file XXX already exists.\n"
CORE-10495 CORE-13672
- Fix how the ERRORLEVEL and the last returned exit code are set by
EXIT and CALL commands, when batch contexts terminate, and when CMD
runs in single-command mode (with /C).
Addendum to commit 26ff2c8e, and reverts commit 7bd33ac4.
See also commit 8cf11060 (r40474).
More information can be found at:
https://ss64.com/nt/exit.htmlhttps://stackoverflow.com/a/34987886/13530036https://stackoverflow.com/a/34937706/13530036
- Move the actual execution of the CMD command-line (in /C or /K
single-command mode) from Initialize() to _tmain(), to put it on par
with the ProcessInput() interactive mode.
- Make ProcessInput() also return the last command's exit code.
CORE-13713 CORE-13736
- In case execution of all batch contexts is stopped (by selecting "All"
at the Ctrl-C/Ctrl-Break prompt), notify as well the CheckCtrlBreak()
signal handler once there are no more batch contexts (this in effect
resets the internal 'bLeaveAll' static flag in CheckCtrlBreak).
This is an adaptation of the fix present in FreeCOM 1.5, first
described in https://gcfl.net/FreeDOS/command.com/bugs074g.html .
- Introduce a ParseErrorEx() helper that sets the 'bParseError' flag and
displays a customized syntax-error message, only for the first syntax
error encountered. Implement ParseError() around the *Ex function.
- In batch mode, echo the original pre-parsed batch file line if a parse
error has been encountered.
- When running a compound command - including IF, FOR, command blocks -,
and that control flow is modified by any CALL/GOTO/EXIT command,
detect this while running the compound command so as to stop it and go
back to the main batch execution loop, that will then set up the actual
new command to run.
- In GOTO, do not process any more parts of a compound command only when
we have found a valid label.
pushd command of cmd.exe didn't treat the quoted parameter correctly.
- Call StripQuotes in SetRootPath function.
- Fix typo of FEATURE_DIRECTORY_STACK.
This PR will enable "Command Prompt" here. CORE-12150
CORE-10495 CORE-13672
- Fix the behaviour of the EXIT command, where it set the last errorlevel
value ONLY when it was called with the /b switch and otherwise kept the
ambient one, instead of always using the value that the user specified
on the command-line.
- When a batch file has terminated, make the Batch() helper returning the
errorlevel value so that, when the batch file has been started with the
CALL command, CALL can in turn set the correct errorlevel value.
Verified with respect to Windows' cmd.exe.
