I am using CreateProcess api to start a batch file. The Code works fine on windows 7 but it is failing on Windows 10.
Below is the snippet of code:
CString param; //it holds the very long string of command line arguments
wstring excFile = L"C:\\program files\\BatchFile.bat";
wstring csExcuPath = L"C:\\program files";
wstring exeWithParam = excFile + _T(" ");
exeWithParam = exeWithParam.append(param);
STARTUPINFO si = { sizeof(si) };
PROCESS_INFORMATION pi;
TCHAR lpExeWithParam[8191];
_tcscpy_s(lpExeWithParam, exeWithParam.c_str());
BOOL bStatus = CreateProcess(NULL, lpExeWithParam, NULL, NULL, TRUE, CREATE_NEW_CONSOLE | CREATE_BREAKAWAY_FROM_JOB, NULL, csExcuPath.c_str(), &si, &pi);
DWORD err;
if (!bStatus)
{
err = GetLastError();
}
With the above code, it is invoking a batch file which will start an executable with given parameters. This code is not working only Windows 10 in our product.
GetLastError is returning error code 122 which code for error "The data area passed to a system call is too small." How to figure out what is causing this error and how it can be resolved?
However, when using the same code in a sample test application is not giving any error and passing.
Any clue/hint why is causing it to fail on Windows 10.
You need to execute cmd.exe with the .bat file as a parameter, don't try to execute the .bat directly.
Also, you don't need lpExeWithParam, you can pass exeWithParam directly to CreateProcess().
Try something more like this instead:
CString param; //it holds the very long string of command line arguments
...
wstring excFile = L"C:\\program files\\BatchFile.bat";
wstring csExcuPath = L"C:\\program files";
wstring exeWithParam = L"cmd.exe /c \"" + excFile + L"\" ";
exeWithParam.append(param);
STARTUPINFOW si = { sizeof(si) };
PROCESS_INFORMATION pi = {};
BOOL bStatus = CreateProcessW(NULL, &exeWithParam[0]/*or exeWithParam.data() in C++17*/, NULL, NULL, TRUE, CREATE_NEW_CONSOLE | CREATE_BREAKAWAY_FROM_JOB, NULL, csExcuPath.c_str(), &si, &pi);
if (!bStatus)
{
DWORD err = GetLastError();
...
}
else
{
...
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
}
Error 122 equates to ERROR_INSUFFICIENT_BUFFER and I think the clue here is "it holds the very long string of command line arguments".
Just how long is it? The limit may be lower on Windows 10 - I recommend you experiment (binary chop).
Also, the documentation for CreateProcess states that you must launch cmd.exe explicitly to run a batch file, so I guess you should do what it says.
I think to run a batch file you must set lpApplicationName to cmd.exe and set lpCommandLine to the following arguments: /c plus the name of the batch file
Related
I'm trying to launch the command line through my c++ program and then have cmd run a command. I'm not sure what I'm doing wrong. I've looked at the MSDN documentation but I'm unable to understand what to change in my code.
Below is the chunk of code that I have written. I'm trying to launch cmd and then run the command in cmdArgs. However, on running the program it just launches the cmd without running the nslookup part of it. I've tried with other commands as well like ipconfig, but they do not get executed. Could someone help me understand what I'm doing wrong.
When I launch the program, it just opens up cmd. What I'm trying to do is have the cmdArgs runs and view the output on the cmd screen.
I'm new to c++, so if this is trivial I apologize. I've looked at other questions on the site, but it seems that the format of cmdArgs is correct - program name followed by the arg.
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
LPTSTR cmdPath = _T("C:\\Windows\\System32\\cmd.exe");
LPTSTR cmdArgs = _T("C:\\Windows\\System32\\cmd.exe nslookup myip.opendns.com. resolver1.opendns.com");
if (!CreateProcess(cmdPath, cmdArgs, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi))
{
std::cout << "Create Process failed: " << GetLastError() << std::endl;
return "Failed";
}
Your program does exactly what you asked it to to: you just start the cmd.exe executable. Just test in a console windows:
C:\Users\xxx>start /w cmd ipconfig
C:\Users\xxx>cmd ipconfig
Microsoft Windows [version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. Tous droits réservés.
C:\Users\xxx>exit
C:\Users\xxx>
So cmd.exe ipconfig just pushed a new cmd.exe without executing the remaining of the line. It is then waiting for commands coming from its standard input.
You must use cmd.exe /c ipconfig to ask the new cmd.exe to execute a command, or cmd.exe /K ipconfig if you want cmd not to exit after first command:
C:\Users\serge.ballesta>cmd /c ipconfig
Configuration IP de Windows
...
So you should write in your code:
...
LPTSTR cmdArgs = _T("C:\\Windows\\System32\\cmd.exe /k nslookup myip.opendns.com. resolver1.opendns.com");
...
Try using this:
wchar_t command[] = L"nslookup myip.opendns.com. resolver1.opendns.com";
wchar_t cmd[MAX_PATH] ;
wchar_t cmdline[ MAX_PATH + 50 ];
swprintf_s( cmdline, L"%s /c %s", cmd, command );
STARTUPINFOW startInf;
memset( &startInf, 0, sizeof startInf );
startInf.cb = sizeof(startInf);
PROCESS_INFORMATION procInf;
memset( &procInf, 0, sizeof procInf );
BOOL b = CreateProcessW( NULL, cmdline, NULL, NULL, FALSE,
NORMAL_PRIORITY_CLASS | CREATE_NO_WINDOW, NULL, NULL, &startInf, &procInf );
DWORD dwErr = 0;
if( b )
{
// Wait till process completes
WaitForSingleObject( procInf.hProcess, INFINITE );
// Check process’s exit code
GetExitCodeProcess( procInf.hProcess, &dwErr );
// Avoid memory leak by closing process handle
CloseHandle( procInf.hProcess );
}
else
{
dwErr = GetLastError();
}
if( dwErr )
{
wprintf(_T(“Command failed. Error %d\n”),dwErr);
}
I'm trying to create something similar to a cmd with Microsoft Visual Studio Express 2013 for Windows Desktop in c++ and one of my function should start a process like open skype by typing "skype.exe". I searched in the internet and found the CreateProcess function that should do the work for me. when I created a function that receives a class value that I created called Line (the name of the class but it doesn't really metter) and used the CreateProcess function in the way that is shown bellow I have to type in my cmd "start skype.exe" but I want it to work like in the regular cmd by writing only "skype.exe", how can I do it?
(the l.parameter is just a string that contains the word skype)
void execute(Line l){
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
LPSTR s = const_cast<char *>(l.parameter.c_str());
if (!CreateProcess(NULL, s, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi))
{
printf("CreateProcess failed (%d).\n", GetLastError());
return;
}
// Wait until child process exits.
WaitForSingleObject(pi.hProcess, INFINITE);
// Close process and thread handles.
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);}
First thing is that:
LPSTR s = const_cast<char *>(l.parameter.c_str());
is bad idea, CreateFile accepts for lpCommandLine non const buffer for a reason - it might modify it:
The system adds a terminating null character to the command-line string to separate the file name from the arguments. This divides the original string into two strings for internal processing.
so you should pass an array, for example:
TCHAR szCmd[MAX_PATH] = {0};
then to your question, if "start skype.exe" works for you and you want to enter only skype.exe at the command line - then why not concatenate strings? for example:
_tcscat(szCmd, _T("start "));
_tcscat(szCmd, parameter.c_str());
and pass szCmd to CreateProcess
the question is whether you use UNICODE build, if yes then make sure parameter is std::wstring, otherwise if you use non-UNICODE build (and it looks like thats true) then std::string is fine.
start is not an executable, it is a feature of cmd.exe, so to invoke start skype.exe via CreateProcess(), you would have to specify cmd.exe as the command and /C start skype.exe as its parameter.
Line l;
line.parameter = "cmd.exe /C start skype.exe";
execute(l);
But that is overkill in this situation, as start is not actually needed, despite what you claim. It is perfectly valid and preferable to invoke skype.exe directly as the command.
However, you have to provide the full path to skype.exe (same if you were to invoke start), otherwise CreateProcess() won't be able to find it, as Skype does not register its .exe file path in the App Paths key of the Registry, or the path to its Phone subfolder (where skype.exe resides) on the system's %PATH% environment variable.
For example:
Line l;
line.parameter = "C:\\Program Files (x86)\\Skype\\Phone\\Skype.exe";
execute(l);
Fortunately, Skype does store the full path to skype.exe in the Registry, specifically in the following key:
HKEY_CURRENT_USER\Software\Skype\Phone
It is stored in a REG_SZ value named "SkypePath".
std::string GetSkypePath()
{
std::string sPath;
HKEY hKey;
if (RegOpenKeyExA(HKEY_CURRENT_USER, "Software\\Skype\\Phone", 0, KEY_QUERY_VALUE, &hKey) == 0)
{
char szPath[MAX_PATH+1] = {0};
DWORD dwPathLen = MAX_PATH;
if (RegQueryValueExA(hKey, "SkypePath", NULL, NULL, (LPBYTE)szPath, &dwPathLen) == 0)
sPath = szPath;
RegCloseKey(hKey);
}
return sPath;
}
bool execute()
{
STARTUPINFO si;
PROCESS_INFORMATION pi;
bool flag = true;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
string f = "dir desktop"
if (CmdLine.parameter != "")
{
LPSTR l1 = const_cast<char *>(f.c_str());
CreateProcess(NULL, l1, NULL, NULL, false, 0, NULL, NULL, &si, &pi);
flag = true;
// WaitForSingleObject(pi.hProcess, INFINITE);
// // Close process and thread handles.
// CloseHandle(pi.hProcess);
// CloseHandle(pi.hThread);
//}
}
return flag;
}
I'm trying to run cmd command by visual studio.
I'm using createprocces (API) in order to run this thing
but I can't understand why it doesn't run anything.
dir is a command understood by cmd.exe, it's not a program you can execute.
You can try the command cmd /k "dir desktop", properly expressed as a C++ string.
E.g.,
auto execute()
-> bool
{
STARTUPINFO si = { sizeof( si ) };
PROCESS_INFORMATION pi = {};
string f = "cmd /k \"dir desktop\"\0";
bool const ok = !!CreateProcess( 0, &f[0], 0, 0, false, 0, 0, 0, &si, &pi );
if( !ok ) { return false; }
WaitForSingleObject(pi.hProcess, INFINITE);
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
return true;
}
Note how the calls to ZeroMemory have been replaced with C++ initialization.
Just by letting the compiler do its job you get shorter, more clear code that is more likely correct, and just as efficient (possibly more). Win win win.
Disclaimer: code not reviewed by compiler.
If the intent is to list the contents of the user's desktop folder, then note that dir desktop doesn't do that. As an interactive command in the command interpreter you could use dir %userprofile%\desktop, and that also works via the Windows Run-dialog. Depending on the command interpreter's behavior for command line arguments it may work directly via CreateProcess, or not.
Generally, when using Windows API level functions it's preferable to use the wchar_t-based text based functions, i.e. define UNICODE before including <windows.h> (or use the ...W functions explicitly).
If you call CreateProcess() with the first parameter set to NULL, then you have to make sure that l1 starts with the module name to call.
As dir is an internal command of the command processor and not an executable, you have to use cmd as module name and give the rest of the parameter as cmd expects them.
So try the following:
string f = "cmd /c=dir desktop";
This question already has answers here:
CreateProcess doesn't pass command line arguments
(8 answers)
Closed 8 years ago.
I am trying to implement CreateProcessW within a dll so that the user can launch an application in a separate process.
For starters I am hardcoding the commands in the code until I figure it out..
I've got
STARTUPINFO si = {sizeof(STARTUPINFO), 0};
si.cb = sizeof(si);
PROCESS_INFORMATION pi = {0};
LPCTSTR AppName=L"c:\\utilities\\depends.exe";
LPTSTR Command = L"c:\\utilities\\tee.exe";
if (CreateProcessW(AppName, Command, 0, 0, 0, CREATE_DEFAULT_ERROR_MODE, 0, 0, &si, &pi)) {
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
return GX_RESULT_OK;
} else {
.. show error msg
}
This will launch Depends but won't open Tee.exe. There's no error, it just ignores the command line parameter. The parameters are correct and I can run it at the run prompt and it works fine. If I leave AppName blank and specify Depends.exe as the Command parameter it also works, but if I specify
LPTSTR Command = L"c:\\utilities\\depends.exe c:\\utilities\\tee.exe";
I get Error 3: "The system cannot find the path specified".
Also, by specifying the lpCurrentDirectory parameter it is likewise ignored.
You must to supply the executable in the command
Appname should contain the full path to the executable
Command should contain also the argv[0]
if you want to open file t.txt with notepad than you can give as follows:
Appname = "c:/windows/notepad.exe";
command = "notepad c:/temp/t.txt";
You doesn't even must to supply the real program name, even fake name will do the job, since it is only a place holder.
like this: command = "fake c:/temp/t.txt";
now in notepad.exe:
argv[0] = "notepad";
argv[1] = "c:/temp/t.txt";
See this full example:
#include <Windows.h>
#include <iostream>
using namespace std;
int main(){
STARTUPINFO si = {sizeof(STARTUPINFO), 0};
si.cb = sizeof(si);
PROCESS_INFORMATION pi = {0};
LPTSTR AppName=L"C:/Windows/notepad.exe";
wchar_t Command[] = L"notepad C:/Temp/t.txt";
DWORD res = CreateProcess(AppName, Command, 0, 0, 0, CREATE_DEFAULT_ERROR_MODE, 0, 0, &si, &pi);
if (res) {
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
return 0;
} else {
cerr<<"error..."<<GetLastError()<<endl;
};
return 0;
}
I am writing a windows QT app that needs to launch other apps. If I use the following windows calls everything works fine:
QString qsExePath = "C:\\Program Files (x86)\\Some Company\\SomeApp.exe";
QString qsCommandLine = "";
DWORD dwLastError = 0;
STARTUPINFO startupInfo;
ZeroMemory(&startupInfo, sizeof(startupInfo));
startupInfo.cb = sizeof(startupInfo);
startupInfo.dwFlags = STARTF_USESHOWWINDOW;
startupInfo.wShowWindow = (WORD)1;
PROCESS_INFORMATION processInfo;
ZeroMemory(&processInfo, sizeof(processInfo));
if (CreateProcess((TCHAR*)(qsExePath.utf16()), (TCHAR*)(qsCommandLine.utf16()),
NULL, NULL, FALSE, 0, NULL, NULL,
&startupInfo, &processInfo))
{
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
else
{
dwLastError = GetLastError();
}
However, if I use the following QT calls it does not work and fails with QProcess::Unknown Error.
QProcess process;
bool bStarted = process.startDetached(qsExePath);
qDebug() << process.error();
I can get QProcess to work if copy SomeApp.exe to my %TMP% directory and change the qsExePath accordingly, so it is obviously some kind of permissions error. I don't understand why though... if it were really permissions, shouldn't my CreateProcess windows call fail?
Your path has spaces in it. You are calling the overloaded version of QProcess.startDetached() that takes a single parameter, so it interprets that as the complete command line to execute. As such, try wrapping the path in quotes, otherwise it will think that "C:\Program" is the program to execute and everything else are arguments, which would be wrong:
QString qsExePath = "\"C:\\Program Files (x86)\\Some Company\\SomeApp.exe\"";
bool bStarted = process.startDetached(qsExePath);
Alternatively, call one of the other overloaded versions of startDetached() and let it work out the necessary quoting internally for you:
QString qsExePath = "C:\\Program Files (x86)\\Some Company\\SomeApp.exe";
bool bStarted = process.startDetached(qsExePath, QStringList());