[stream-refactor] import fd_check.py used by create_child_test

tests/data/fd_check.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python
+
+import fcntl
+import os
+import sys
+
+
+def ttyname(fd):
+    try:
+        t = os.ttyname(fd)
+        if hasattr(t, 'decode'):
+            t = t.decode()
+        return t
+    except OSError:
+        return None
+
+
+def controlling_tty():
+    try:
+        fp = open('/dev/tty')
+        try:
+            return ttyname(fp.fileno())
+        finally:
+            fp.close()
+    except (IOError, OSError):
+        return None
+
+
+fd = int(sys.argv[2])
+st = os.fstat(fd)
+
+if sys.argv[3] == 'write':
+    os.write(fd, u'TEST'.encode())
+    buf = u''
+else:
+    buf = os.read(fd, 4).decode()
+
+open(sys.argv[1], 'w').write(repr({
+    'buf': buf,
+    'flags': fcntl.fcntl(fd, fcntl.F_GETFL),
+    'st_mode': st.st_mode,
+    'st_dev': st.st_dev,
+    'st_ino': st.st_ino,
+    'ttyname': ttyname(fd),
+    'controlling_tty': controlling_tty(),
+}))
+
+open('/tmp/foo', 'w').write(repr({
+    'buf': buf,
+    'flags': fcntl.fcntl(fd, fcntl.F_GETFL),
+    'st_mode': st.st_mode,
+    'st_dev': st.st_dev,
+    'st_ino': st.st_ino,
+    'ttyname': ttyname(fd),
+    'controlling_tty': controlling_tty(),
+}))