rename mvc at lvc

1 files changed, 49 insertions, 0 deletions

diff --git a/lvc/execute.py b/lvc/execute.py
new file mode 100644
index 0000000..af6f463
--- /dev/null
+++ b/lvc/execute.py
@@ -0,0 +1,49 @@
+"""execute.py -- Run executable programs.
+
+lvc.execute wraps the standard subprocess module in for MVC.
+"""
+
+import os
+import subprocess
+import sys
+
+CalledProcessError = subprocess.CalledProcessError
+
+def default_popen_args():
+    retval = {
+        'stdin': open(os.devnull, 'rb'),
+        'stdout': subprocess.PIPE,
+        'stderr': subprocess.STDOUT,
+    }
+    if sys.platform == 'win32':
+        retval['startupinfo'] = subprocess.STARTUPINFO()
+        retval['startupinfo'].dwFlags |= subprocess.STARTF_USESHOWWINDOW
+    return retval
+
+class Popen(subprocess.Popen):
+    """subprocess.Popen subclass that adds MVC default behavior.
+
+    By default we:
+      - Use a /dev/null equivilent for stdin
+      - Use a pipe for stdout
+      - Redirect stderr to stdout
+      - use STARTF_USESHOWWINDOW to not open a console window on win32
+
+    These are just defaults though, they can be overriden by passing different
+    values to the constructor
+    """
+    def __init__(self, commandline, **kwargs):
+        final_args = default_popen_args()
+        final_args.update(kwargs)
+        subprocess.Popen.__init__(self, commandline, **final_args)
+
+def check_output(commandline, **kwargs):
+    """MVC version of subprocess.check_output.
+
+    This performs the same default behavior as the Popen class.
+    """
+    final_args = default_popen_args()
+    # check_output doesn't use stdout
+    del final_args['stdout']
+    final_args.update(kwargs)
+    return subprocess.check_output(commandline, **final_args)