From d47419bb73993580eea677b548b1ce526845ebd2 Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Wed, 21 Dec 2016 00:11:23 +0300
Subject: [PATCH] os: Implement popen().

---
 os/os/__init__.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/os/os/__init__.py b/os/os/__init__.py
index ea6a37c9..30452cf0 100644
--- a/os/os/__init__.py
+++ b/os/os/__init__.py
@@ -254,3 +254,23 @@ def urandom(n):
     import builtins
     with builtins.open("/dev/urandom", "rb") as f:
         return f.read(n)
+
+def popen(cmd, mode="r"):
+    import builtins
+    i, o = pipe()
+    if mode[0] == "w":
+        i, o = o, i
+    pid = fork()
+    if not pid:
+        if mode[0] == "r":
+            close(1)
+        else:
+            close(0)
+        close(i)
+        dup(o)
+        close(o)
+        s = system(cmd)
+        _exit(s)
+    else:
+        close(o)
+        return builtins.open(i, mode)