在C ++中将系统命令与参数一起使用

Question

So I'm doing a project for school and was trying to use the windows function "mkdir", but the directory name would be a string given by the program. Here's the (not very useful) code:

string c,a;
cin>>c;
if(c.compare("mkdir")==0)
    cin>>a;
    system("mkdir"); //here I want to make the directory
}

Answer 1

As others have mentioned, it would be better to create the directory without using the system call. If you would like to use that method regardless, you need to build a command string which includes your arguments prior to passing it to system .

char command[100];
sprintf(command, "mkdir %s", a);
system(command);

Answer 2

Directories don't exist for the C++11 (or C++14) standard. Later C++ standard (eg C++17 ...) might offer the std::filesystem library.

You could use operating system specific primitives. On Linux and POSIX, consider the mkdir(2) system call (and CreateDirectory function on Windows).

You could find framework libraries (eg POCO , Qt , Boost , ....) wrapping these, so with these libraries you won't care about OS specific functions.

but the directory name would be a string given by the program.

Then you could consider building a command as a runtime C string for system(3) . Eg with snprintf(3) (or with some std::string operation). Beware of code injection (eg think of the malicious user providing /tmp/foo; rm -rf $HOME as his directory name on Linux)!

Answer 3

如果要使用WinApi创建文件夹，请参见CreateFolder

Answer 4

The simplest solution I can think of:

string c;
cin >> c;
if(c == "mkdir") {
    string a;
    cin >> a;
    system("mkdir " + a);
}

But if this project involves writing some kind of command shell, system is very likely off-limits and you're expected to use the operating system's API directly.