Assign to string dir the path of the working directory.
(This is not necessarily the folder containing the executable itself)
New implementation

Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating material.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations
with Ada.Directories; use Ada.Directories;
Dir : String := Current_Directory;
#include <unistd.h>
char *dir = getcwd(NULL, 0);
#include <filesystem>
dir = std::filesystem::current_path();
using System.IO;
string path = Directory.GetCurrentDirectory();
import std.path;
string dir = absolutePath;
use iso_c_binding, only: c_char, c_size_t,c_ptr, c_null_ptr, c_associated
     function c_getcwd (buf, size) bind(C,name="getcwd") result(r)
       type(c_ptr) :: r
       character(kind=c_char), dimension(*), intent(out) :: buf
       integer(kind=c_size_t), value :: size
     end function c_getcwd
  end interface

    if (c_associated(c_getcwd (buf, size(buf,kind=c_size_t)))) then
       n = findloc(buf,achar(0),1)
       allocate (character(len=n-1) :: dir)
       dir(1:n-1) = transfer(buf(1:n-1),dir(1:n-1))
    end if
import "os"
dir, err := os.Getwd()
def dir = new File('.').absolutePath
import System.Directory
dir <- getCurrentDirectory
let dir = process.cwd ()
String dir = System.getProperty("user.dir");
import java.io.File;
String dir = new File("").getAbsolutePath();
String path = this.getClass().getClassLoader().getResource("").getPath();
dir = os.getenv("PWD") or io.popen("cd"):read()
$dir = getcwd();
dir := expandfilename('.');
use Cwd;
my $dir = getcwd();
import os
dir = os.getcwd()
dir = Dir.pwd
use std::env;
let dir = env::current_dir().unwrap();