add example

Author: wassup05

example/system/CMakeLists.txt

@@ -13,3 +13,4 @@ ADD_EXAMPLE(process_7)
 ADD_EXAMPLE(sleep)
 ADD_EXAMPLE(make_directory)
 ADD_EXAMPLE(remove_directory)
+ADD_EXAMPLE(cwd)

example/system/example_cwd.f90

@@ -0,0 +1,33 @@
+! Illustrate the usage of get_cwd, set_cwd
+program example_cwd
+    use stdlib_system, only: get_cwd, set_cwd
+    use stdlib_error, only: state_type
+    implicit none 
+
+    character(len=:), allocatable :: path
+    type(state_type) :: err
+
+    call get_cwd(path, err)
+
+    if (err%error()) then
+        print *, "Error getting current working directory: "//err%print()
+    end if
+    
+    print *, "CWD: "//path
+
+    call set_cwd("./src", err)
+
+    if (err%error()) then
+        print *, "Error setting current working directory: "//err%print()
+    end if
+
+    call get_cwd(path, err)
+
+    if (err%error()) then
+        print *, "Error getting current working directory after using set_cwd: "//err%print()
+        return
+    end if
+    
+    print *, "CWD: "//path
+end program example_cwd
+