我遇到了一个严重的问题。我需要通过C++执行CMD命令行，但不希望控制台窗口显示出来。因此我不能使用system(cmd)，因为会显示窗口。
我尝试过winExec(cmd, SW_HIDE)，但这也不起作用。CreateProcess是另一个我尝试过的，但这只能运行程序或批处理文件。
最终我尝试了ShellExecute：
ShellExecute( NULL, "open",
"cmd.exe",
"ipconfig > myfile.txt",
"c:\projects\b",
SW_SHOWNORMAL
);
有人能看出上面的代码有什么问题吗？我使用SW_SHOWNORMAL，直到我知道这个可以正常工作。
我真的需要一些帮助。目前还没有发现任何问题，而我已经尝试了相当长的一段时间。如果有任何建议，都非常感谢 :)
将输出重定向到自己的管道是更整洁的解决方案，因为它避免了创建输出文件，但以下方法同样有效：
ShellExecute(0, "open", "cmd.exe", "/C ipconfig > out.txt", 0, SW_HIDE);
你不会看到命令行窗口，输出结果也如预期一样被重定向了。
除了/C之外，你的代码可能会失败，因为你将路径指定为"c:\projects\b"而不是"c:\\projects\\b"。
这是我实现的一个DosExec函数，它可以（静默地）执行任何DOS命令，并将生成的输出作为Unicode字符串检索。
// Convert an OEM string (8-bit) to a UTF-16 string (16-bit)
#define OEMtoUNICODE(str) CHARtoWCHAR(str, CP_OEMCP)
/* Convert a single/multi-byte string to a UTF-16 string (16-bit).
We take advantage of the MultiByteToWideChar function that allows to specify the charset of the input string.
*/
LPWSTR CHARtoWCHAR(LPSTR str, UINT codePage) {
size_t len = strlen(str) + 1;
int size_needed = MultiByteToWideChar(codePage, 0, str, len, NULL, 0);
LPWSTR wstr = (LPWSTR) LocalAlloc(LPTR, sizeof(WCHAR) * size_needed);
MultiByteToWideChar(codePage, 0, str, len, wstr, size_needed);
return wstr;
}
/* Execute a DOS command.
If the function succeeds, the return value is a non-NULL pointer to the output of the invoked command.
Command will produce a 8-bit characters stream using OEM code-page.
As charset depends on OS config (ex: CP437 [OEM-US/latin-US], CP850 [OEM 850/latin-1]),
before being returned, output is converted to a wide-char string with function OEMtoUNICODE.
Resulting buffer is allocated with LocalAlloc.
It is the caller's responsibility to free the memory used by the argument list when it is no longer needed.
To free the memory, use a single call to LocalFree function.
*/
LPWSTR DosExec(LPWSTR command){
// Allocate 1Mo to store the output (final buffer will be sized to actual output)
// If output exceeds that size, it will be truncated
const SIZE_T RESULT_SIZE = sizeof(char)*1024*1024;
char* output = (char*) LocalAlloc(LPTR, RESULT_SIZE);
HANDLE readPipe, writePipe;
SECURITY_ATTRIBUTES security;
STARTUPINFOA start;
PROCESS_INFORMATION processInfo;
security.nLength = sizeof(SECURITY_ATTRIBUTES);
security.bInheritHandle = true;
security.lpSecurityDescriptor = NULL;
if ( CreatePipe(
&readPipe, // address of variable for read handle
&writePipe, // address of variable for write handle
&security, // pointer to security attributes
0 // number of bytes reserved for pipe
) ){
GetStartupInfoA(&start);
start.hStdOutput = writePipe;
start.hStdError = writePipe;
start.hStdInput = readPipe;
start.dwFlags = STARTF_USESTDHANDLES + STARTF_USESHOWWINDOW;
start.wShowWindow = SW_HIDE;
// We have to start the DOS app the same way cmd.exe does (using the current Win32 ANSI code-page).
// So, we use the "ANSI" version of createProcess, to be able to pass a LPSTR (single/multi-byte character string)
// instead of a LPWSTR (wide-character string) and we use the UNICODEtoANSI function to convert the given command
if (CreateProcessA(NULL, // pointer to name of executable module
UNICODEtoANSI(command), // pointer to command line string
&security, // pointer to process security attributes
&security, // pointer to thread security attributes
TRUE, // handle inheritance flag
NORMAL_PRIORITY_CLASS, // creation flags
NULL, // pointer to new environment block
NULL, // pointer to current directory name
&start, // pointer to STARTUPINFO
&processInfo // pointer to PROCESS_INFORMATION
)){
// wait for the child process to start
for(UINT state = WAIT_TIMEOUT; state == WAIT_TIMEOUT; state = WaitForSingleObject(processInfo.hProcess, 100) );
DWORD bytesRead = 0, count = 0;
const int BUFF_SIZE = 1024;
char* buffer = (char*) malloc(sizeof(char)*BUFF_SIZE+1);
strcpy(output, "");
do {
DWORD dwAvail = 0;
if (!PeekNamedPipe(readPipe, NULL, 0, NULL, &dwAvail, NULL)) {
// error, the child process might have ended
break;
}
if (!dwAvail) {
// no data available in the pipe
break;
}
ReadFile(readPipe, buffer, BUFF_SIZE, &bytesRead, NULL);
buffer[bytesRead] = '\0';
if((count+bytesRead) > RESULT_SIZE) break;
strcat(output, buffer);
count += bytesRead;
} while (bytesRead >= BUFF_SIZE);
free(buffer);
}
}
CloseHandle(processInfo.hThread);
CloseHandle(processInfo.hProcess);
CloseHandle(writePipe);
CloseHandle(readPipe);
// convert result buffer to a wide-character string
LPWSTR result = OEMtoUNICODE(output);
LocalFree(output);
return result;
}
cmd /c 命令行，那么 > 重定向当然可以工作。 - Eryk Sunhttps://github.com/vlsireddy/remwin/tree/master/remwin
这是一个服务器程序，它：你可以使用
string command = "start /B cmd /c " + myCommand;
system(command.c_str());
希望这对你有用
#define UNICODEtoANSI(str) WCHARtoCHAR(str, CP_OEMCP)
LPSTR WCHARtoCHAR(LPWSTR wstr, UINT codePage) {
int len = (int)wcslen(wstr) + 1;
int size_needed = WideCharToMultiByte(codePage, 0, wstr, len, NULL, 0, NULL, NULL);
LPSTR str = (LPSTR)LocalAlloc(LPTR, sizeof(CHAR) * size_needed);
WideCharToMultiByte(codePage, 0, wstr, len, str, size_needed, NULL, NULL);
return str;
}
不安全的CRT字符串函数调用：
为了使代码编译通过，请用以下调用替换strcpy和strcat
strcpy_s(output, sizeof(output), "");
strcat_s(output, RESULT_SIZE, buffer);
移除冗余的空终止符：
在 do-while 循环中移除：
buffer[bytesRead] = '\0';
因为 strcat_s 已经处理了这个问题。