--- /home/user/.tmp/cpython-3de678cd184d/Modules/main.c	2014-12-18 23:47:55.000000000 +0100
+++ /home/user/.tmp/cpython-edited/Modules/main.c	2014-12-30 16:52:22.126885885 +0100
@@ -37,7 +37,7 @@
 static int  orig_argc;
 
 /* command line options */
-#define BASE_OPTS L"bBc:dEhiIJm:OqRsStuvVW:xX:?"
+#define BASE_OPTS L"bBc:dEhiIJm:Op:qRsStuvVW:xX:?"
 
 #define PROGRAM_OPTS BASE_OPTS
 
@@ -63,6 +63,8 @@
 -m mod : run library module as a script (terminates option list)\n\
 -O     : optimize generated bytecode slightly; also PYTHONOPTIMIZE=x\n\
 -OO    : remove doc-strings in addition to the -O optimizations\n\
+-p pth : let pth become the highest priority module search path,\n\
+         earlier ones have higher priority in case of multiple such arguments\n\
 -q     : don't print version and copyright messages on interactive startup\n\
 -s     : don't add user site directory to sys.path; also PYTHONNOUSERSITE\n\
 -S     : don't imply 'import site' on initialization\n\
@@ -345,6 +347,17 @@
     PyObject *warning_option = NULL;
     PyObject *warning_options = NULL;
 
+    int searchpath_args_num = 0;
+    wchar_t ** searchpath_args = NULL;
+    PyObject * sys_path = NULL;
+
+    searchpath_args =
+        /* max number of `-p` arg strings <= argc */
+        (wchar_t **)PyMem_RawCalloc(argc, sizeof(wchar_t*));
+    if(searchpath_args == NULL){
+        Py_FatalError("not enough memory to reference searchpath arguments");
+    }
+
     cf.cf_flags = 0;
 
     orig_argc = argc;           /* For Py_GetArgcArgv() */
@@ -489,6 +502,10 @@
             /* Ignored */
             break;
 
+        case 'p':
+            searchpath_args[searchpath_args_num++] = _PyOS_optarg;
+            break;
+
         /* This space reserved for other options */
 
         default:
@@ -669,6 +686,41 @@
     Py_Initialize();
     Py_XDECREF(warning_options);
 
+    sys_path = PySys_GetObject("path");
+    if (sys_path == NULL) {
+        Py_FatalError("failure in handling of -p arguments, unable to get sys.path\n");
+    } else {
+    /* This loop is O(n^2), since insert is O(n). Creating a new list, and
+     * appending everything would be O(n), given the amortized O(1) append. */
+    /* The first `-p` argument must be the last one prepended,
+     * so it becomes the head of sys.path. The second ... */
+        for(/* `case 'p'` */; 0<searchpath_args_num; --searchpath_args_num){
+            int searchpath_args_idx = searchpath_args_num-1;
+            wchar_t *wPath = searchpath_args[searchpath_args_idx];
+            PyObject *uPath = NULL;
+            PyObject *bPath = NULL;
+            struct stat sb;
+            if ((uPath = PyUnicode_FromWideChar(wPath,wcslen(wPath))) == NULL){
+                Py_FatalError("failure in handling of -p argument, conversion to unicode failed \n");
+            }
+            if ((bPath = PyUnicode_EncodeFSDefault(uPath)) == NULL){
+                Py_FatalError("failure in handling of -p argument, encoding of path failed\n");
+            }
+            if( ! (stat(PyBytes_AsString(bPath),&sb) == 0
+                   && S_ISDIR(sb.st_mode)) )
+            {
+                fprintf(stderr, "invalid -p argument, '%s' is not a directory\n",
+                     PyBytes_AsString(bPath));
+                Py_Exit(ENOTDIR);
+            }
+            Py_DECREF(bPath);
+            if (PyList_Insert(sys_path, 0, uPath)) {
+                Py_FatalError("failure in handling of -p argument, could not prepend to sys.path\n");
+            }
+        }
+    }
+    PyMem_RawFree(searchpath_args);
+
     if (!Py_QuietFlag && (Py_VerboseFlag ||
                         (command == NULL && filename == NULL &&
                          module == NULL && stdin_is_interactive))) {