Re: Finding the path to a executable?

[Tommi]

On Wednesday, 7 August 2013 at 05:31:24 UTC, Alan wrote:
Hello!  This may seem like a simple question, maybe an 
embarassing question but how would I fetch the absolute path to 
the directory where my executable is located?  My wording is 
known to be confusing so I will give an example:

cd ~/projects/program
dmd Program.d -ofProgram

That executable would be located in /home/alan/projects/program 
for example.  SO my question is how would I fetch the absolute 
path to that directory?

Thanks for any help!

This should work on at least couple of systems, but I haven't 
tested this on other than Mac. Also, it's not completely robust, 
because paths could be longer than 4096 chars.

version(Windows) {
    import std.c.windows.windows;
}
else version(OSX) {
    private extern(C) int _NSGetExecutablePath(char* buf, uint* 
bufsize);
}
else version(linux) {
    import std.c.linux.linux;
}
else {
    static assert(0);
}
import std.conv;

// Returns the full path to the currently running executable
string executablePath()
{
    static string cachedExecutablePath;

    if (!cachedExecutablePath) {
        char[4096] buf;
        uint filePathLength;

        version(Windows) {
            filePathLength = GetModuleFileNameA(null, buf.ptr, 
buf.length - 1);
            assert(filePathLength != 0);
        }
        else version(OSX) {
            filePathLength = cast(uint) (buf.length - 1);
            int res = _NSGetExecutablePath(buf.ptr, 
&filePathLength);
            assert(res == 0);
        }
        else version(linux) {
            filePathLength = readlink(toStringz(selfExeLink), 
buf.ptr, buf.length - 1);
        }
        else {
            static assert(0);
        }
        cachedExecutablePath = to!string(buf[0 .. 
filePathLength]);
    }
    return cachedExecutablePath;
}

// Returns the file name of the currently running executable
string executableName()
{
    return executablePath().baseName();
}

// Returns the path to the directory of the currently running 
executable
string executableDirPath()
{
    return executablePath().dirName();
}