I have a Windows executable (whoami) which is crashing every so often. It's called from another process to get details about the current user and domain. I'd like to know what parameters are passed when it fails.
Does anyone know of an appropriate way to wrap the process and write it's command line arguments to log while still calling the process?
Say the command is used like this:
'whoami.exe /all'
I'd like a script to exist instead of the whoami.exe (with the same filename) which will write this invocation to log and then pass on the call to the actual process.
From a batch file:
echo Parameters: %* >> logfile.txt
whoami.exe %*
With the caveat that you can have problems if the parameters contain spaces (and you passed the in escaping with "), because the command-line parser basically de-escapes them and they should be re-escaped before passed to an other executable.
You didn't note which programming language. It is not doable from a .bat file if that's what you wanted, but you can do it in any programming language. Example in C:
int main(int argc, void **argv)
{
// dump contents of argv to some log file
int i=0;
for (i=0; i<argc; i++)
printf("Argument #%d: %s\n", argv[i]);
// run the 'real' program, giving it the rest of argv vector (1+)
// for example spawn, exec or system() functions can do it
return 0; // or you can do a blocking call, and pick the return value from the program
}
I don't think using a "script" will work, since the intermediate should have a .exe extension for your ploy to work.
I would write a very small command line program to do this; something like the following (written in Delphi/Virtual Pascal so it will result in a Win32 executable, but any compiled language should do):
program PassThrough;
uses
Dos; // Imports the Exec routine
const
PassTo = 'Original.exe'; // The program you really want to call
var
CommandLine: String;
i: Integer;
f: Text;
begin
CommandLine := '';
for i := 1 to ParamCount do
CommandLine := CommandLine + ParamStr(i) + ' ';
Assign(f,'Passthrough.log');
Append(f);
Writeln(f, CommandLine); // Write a line in the log
Close(f);
Exec(PassTo, CommandLine); // Run the intended program
end.
Can't you just change the calling program to log the parameters it used to call the process, and the exit code?
This would be way easier than trying to dig into whoami.exe
Look for whoami.exe, BACK IT UP, replace it with your own executable and see do whatever you like with it's parameters (maybe save them in a text file).
If you can reproduce the crash, use Process Explorer before crashed process is terminated to see its command line.
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx
Related
I'm using Lua in a cmd window under Windows.
I use "cat" (from UnxUtils) to feed a file to a Lua script. The script uses "io.read(1)" to read one byte at a time.
local b, n ;
n = -1 ;
b = true ;
while b do
n = n + 1 ;
b = io.read(1) ;
end ;
print( n, "bytes read" ) ;
When I feed the script a 333K .EXE file, it claims "24025 bytes read".
Feed the same .EXE to "wc" (another UnxUtils), and wc correctly says 333008.
> cat "Firefox Installer.exe" | lua count.lua
24025 bytes read
cat: write error: Invalid argument
> cat "Firefox Installer.exe" | wc
1408 8674 333008
Since I get the expected answer when I "cat | wc", I don't think there's anything wrong with the "cat" program, or with Windows' implementation of redirection.
I am not looking for advice on how to make the Lua script more efficient. I do not need advice on how to make the script read directly from a file (that works as expected). I am looking for a clue as to where to look for the reason I can't use Lua to write a filter (and be able to trust the results).
I have looked at the input file to see if a Ctrl-Z or Ctrl-D was the reason for the early shut-off -- they occur very early in the file.
I tried reading after "io.read()" returned "false": the script admitted to seeing more bytes, but still no more than 45K of the 333K input file.
Copied from my comments:
Likely to be a Windows issue (see e.g. this answer). Windows treats binary and text "streams" / files differently. I would assume that your program's stdin is a text stream by default; it isn't possible to change the mode of stdin to binary later on using plain Lua, you'll need a library for that. Something like lfs = require("lfs"); lfs.setmode(io.stdin, "binary") might work (using the LuaFileSystem library).
You could also try to fix your script invocation to set the correct mode using a script which changes stdin to binary mode before invoking your Lua script:
./stdbin.c:
#include <stdio.h>
#include <unistd.h>
#include <assert.h>
int main(int argc, char** argv) {
if (argc < 1) {
printf("Arguments: <program> {args}\n");
return 1;
}
// See https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/setmode?redirectedfrom=MSDN&view=msvc-170
if (_setmode(_fileno(stdin), _O_BINARY) == -1)
perror("_setmode failed");
execvp("lua", ++argv);
// execvp only returns if there is an error
perror("execvp failed");
return 1;
}
Note: Untested. Usage: ./stdbin lua count.lua.
(This is an addition to LMD's answer)
In LuaJIT no external libraries and executables are needed:
local ffi = require"ffi"
ffi.cdef"int _setmode(int,int)"
ffi.C._setmode(0, 0x8000)
-- Now io.read() will return binary data
I am receiving data from serial port. I use HWUT for comparing my test results. The content from receive buffer cannot be directly used for comparison of GOOD and OUT result. Becuase the OUT will always have unnecessary command prompts, enters and other stuff. I am looking to select what must be written from read buffer into OUT file. For example below is an example
←[36m
A> target cmd
←[36m
{t=3883.744541 s} Received data
A> result : 1
bytes read 518Closing serial port...OK
And I would like the out file to only have 'result : 1'.
When i checked the code, messages.py seems to be printing to std out. But not sure if that is being used for printing into OUT file. How can this be achieved?
Anything that you print to 'stdout' should appear in the "OUT/*" files. If it does not, then this would have nothing to do with receiption via serial line(s). Here is what I would do to analyze:
In your connector application there must be something like
receive_n = receive(.., &buffer[0], Size);
buffer[receive_n] = '\0'; /* terminating zero */
printf("%s", &buffer[0]);
If this is so, then
Write in paralell into a log file.
static log_fh = fopen("tmp.log", "wb");
...
printf("%s", &buffer[0]);
fwrite((void*)buffer, 1, received_n, log_fh);
Compare 'tmp.log' with the file in OUT.
If there is a difference, HWUT is to blame.
Check the output before you write it.
if( my_condition(buffer, received_n) ) printf("%s", &buffer[0]);
HWUT has an internal infrastructure to post-process test output, but it is not documented and therefore not reliable--at the time of this writing.
Edit the file "hwut-info.dat" in your TEST directory.
These R my Tests on Something Important (Title)
-------------------------------------------------------
--not *.exe
bash execute-this.sh
-------------------------------------------------------
The --not *.exe makes sure that HWUT will not execute the *.exe files which you compiled. The bash execute-this.sh line lets HWUT consider the file execute-this.sh as a test application and call it with 'bash'.
Inside the execute-this.sh you might want to make your application, execute it and filter the output, i.e.
#! bash
make my-test.exe
./my-test.exe | awk ' /^A>/ '
which will print only those lines which start with 'A>'. grep and awk are your friends, here. You might want to familiarize yourself with these two.
Alternatively, you may filter directly in your connection application.
I saw this question here: How to get an output of an Exec'ed program in Inno Setup?
But I can't get it to work myself, the commented out code are my attempts to make this work, but I resorted to a bat file because I couldn't make my redirection work. CacheInstanceName and CacheInstanceDir are global variable defined elsewhere:
function CheckCacheExists(): Integer;
var
args: String;
buffer: String;
ResultCode: Integer;
begin
// args := 'qlist ' + CacheInstanceName + ExpandConstant(' nodisplay > {tmp}\appcheck.txt');
// MsgBox(args, mbInformation, MB_OK);
// Exec(CacheInstanceDir + '\bin\ccontrol.exe', 'qlist ' + CacheInstanceName + ExpandConstant(' nodisplay > "{tmp}\appcheck.txt"'), '', SW_SHOW,
ExtractTemporaryFile('checkup.BAT');
Exec(ExpandConstant('{tmp}\checkup.BAT'), CacheInstanceDir + ' ' +
CacheInstanceName + ' ' + ExpandConstant('{tmp}'), '', SW_SHOW,
ewWaitUntilTerminated, ResultCode);
LoadStringFromFile(ExpandConstant('{tmp}\appcheck.txt'),buffer);
if Pos('^', buffer) = 0 then
begin
Result := 0
end
else
begin
Result := 1
end
end;
What am I doing wrong?
The output redirection syntax is a feature of the command prompt, not the core Windows APIs. Therefore if you want to redirect output then you need to invoke the command via {cmd} /c actual-command-line > output-file. Don't forget to include quotes where appropriate, as {tmp} (and other constants) may contain spaces.
However, you should strongly consider rewriting whatever is in that batch file into actual code. Anything you can do in a batch file you can do either directly in the Inno script or in a DLL that you call from the script. And this permits you greater control over error checking and the format of whatever data you want to retrieve.
Try running the command directly on your command line with the arguments in your args string to see what the result is which may give an indication of the problem.
Also, check that the file you are trying to redirect your output to is not in use by another process. I have found that when this occurs the actual command may execute successfully with the Exec command returning True but the ResultCode indicates an error and no output is written to the file used in the redirect. In this particular instance of the file being used by another instance the SysErrorMessage(ResultCode) command returns simply Incorrect function. However, testing directly on the command line as I mentioned first returns that the file is in use by another process.
I have a problem with the GetCommandLine() API.
It usually returns the executable name followed by a space and arguments. As documentation says, the first token may not have the complete path to the image and blah blah blah.
I never had problems until now that I used CreateProcess with lpApplicationName not NULL.
If I use:
CreateProcess(NULL, "\"c:\\myexe.exe\" param1 param2", ...)
GetCommandLine returns "c:\myexe.exe param1 param2" as expected.
But if I use:
CreateProcess("C:\myexe.exe", "param1 param2")
GetCommandLine returns only "param1 param2".
How do I know if the executable name is given on the command line if another application launches mine?
Also, MFC startup code assumes that the first token on the command line is the executable name and skips it. But if you launch a MFC application with the second CreateProcess API example, MFC's code will skip the first argument.
Not your problem. It's the job of the other application to construct the command line properly. You should simply assume that the first argument is an executable name as expected and skip over it.
I have a workaround which can be helpful in a case like this.
I guess we always be able to check how our module was been started.
In this case we should check first argument.
I will write code because I have some problem with English.
Here two ways:
The first case. we can compare module name with first command line argument.
something like this:
const TCHAR* csCommandLine = ::GetCommandLine();
// Attention!!! the first symbol can be quete
if (*csCommandLine == _T('\"'))
csCommandLine++;
TCHAR sModuleFileName[MAX_PATH];
DWORD dwModuleFileName = ::GetModuleFileName(NULL, sModuleFileName, MAX_PATH);
if (dwModuleFileName && !_tcsncmp(csCommandLine, sModuleFileName, dwModuleFileName)) {
// The command line contains the module name.
}
The second case. we can try to get file attributes for the first command line argument
something like this:
// Attention!!! don't use it case if you are going to pass a file path in command line arguments.
int nArgc;
LPTSTR* szArglist = ::CommandLineToArgvW(::GetCommandLine(), &nArgc);
if (nArgc && ::GetFileAttributes(szArglist[0]) != INVALID_FILE_ATTRIBUTES) {
// The command line contains the module name.
}
::LocalFree(szArglist);
I hope it can be helpful someone.
Regards, Vladimir
This is related to: How do I read the results of a system() call in C++?
I am trying to do the exact the same thing only that my program needs to pass 'multiple parameters with spaces' to the command. I need the command line output and the exit code from the process.
Example: An example with Textpad. The application I'm really using prints stuff on stdout.
string command1 = "\"C:\Program Files\TextPad 5\Textpad.exe\" C:\readme0.txt";
string command2 = "\"C:\Program Files\TextPad 5\Textpad.exe\" \"C:\read me2.txt\"";
cout << system(command1.c_str()) << endl;
cout << system(command1.c_str()) << endl;
Output:
0
'C:\Program' is not recognized as an internal or external command,
operable program or batch file.
1
The first call to system passes and second one fails with the error above. _popen in Windows works similarly on Windows so no help there. I can easily do this on Linux as I can escape spaces in the parameters without having to use quotes.
An alternative is to write a huge chunk of non-cross-platform code as listed here:
http://msdn.microsoft.com/en-us/library/ms682499(VS.85).aspx
But in case I want to avoid that, are there any alternatives to system() and _popen() on Windows?
Thanks!
The lowest level Windows API function used by _popen() and system() is CreateProcess().
However CreateProcess() is not that simple to use - especially when you want to get the process'es output or write to the process'es input.
CreateProcess() will definitely work with file names that contain space characters (as long as they are written in quotation marks the way you did that).
The following solves the spaces in the path problem. Catching the output of the command is much more difficult, however:
#include <string>
#include <cstdlib>
using namespace std;
int main() {
string cmd = "\"c:\\program files\\notepad++\\notepad++.exe\"";
system( cmd.c_str() );
return 0;
}
A bunch of utility libraries have taken that chunk of non-portable code and wrapped it up with a portable interface. For an example, see Qt's QProcess.
I do this (note - this is VB.NET code), so I can write the output of the command to my log file (it's wrapped in a RunCommand() method):
Try
Dim myprocess As New Process()
myprocess.StartInfo.FileName = "C:\Program Files\TextPad 5\Textpad.exe"
myprocess.StartInfo.RedirectStandardOutput = True
myprocess.StartInfo.UseShellExecute = False
' inArgs are the arguments on the command line to the program
myprocess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden
myprocess.StartInfo.Arguments = "C:\readme0.txt"
' the dir to set as default when the program runs
Then myprocess.StartInfo.WorkingDirectory = "C:\Program Files\TextPad 5\"
myprocess.Start()
' grab a reader to the standard output of the program
procReader = myprocess.StandardOutput()
' read all the output from the process
While (Not procReader.EndOfStream)
procLine = procReader.ReadLine()
' write the output to my log
writeNotes(procLine)
End While
procReader.Close()
Catch ex As Exception
' Write the error to my log
writeErrors("Couldn't execute command "C:\Program Files\TextPad 5\Textpad.exe", ex)
End Try
I think ShellExecute() is what you're looking for.
Never use system() in Windows !
Just redirect i/o handles.