use ctypes as fallback

Author: randy3k

all/ptyprocess/resource.py

@@ -1,11 +1,36 @@
+import sys
 import subprocess
+import ctypes
+import ctypes.util
 
 
-RLIMIT_NOFILE = 7
+class StructRLimit(ctypes.Structure):
+    _fields_ = [('rlim_cur', ctypes.c_ulong), ('rlim_max', ctypes.c_ulong)]
+
+
+if sys.platform == "darwin":
+    RLIMIT_NOFILE = 8
+else:
+    RLIMIT_NOFILE = 7
+
+
+def _getgetrlimit(resource):
+    try:
+        limits = StructRLimit()
+        libc = ctypes.CDLL(ctypes.util.find_library('c'), use_errno=True)
+        libc.getrlimit(resource, ctypes.byref(limits))
+        return (limits.rlim_cur, limits.rlim_max)
+    except Exception:
+        # better than error !?
+        return (10000, None)
 
 
 def getrlimit(resource):
     if resource == RLIMIT_NOFILE:
-        soft_limit = int(subprocess.check_output(['sh', '-c', 'ulimit -Sn']))
+        try:
+            soft_limit = int(subprocess.check_output(
+                ['sh', '-c', 'ulimit -Sn'], stderr=subprocess.PIPE))
+        except Exception:
+            soft_limit = _getgetrlimit(resource)[0]
         hard_limit = None
         return (soft_limit, hard_limit)