Python2.5 subprocess added functions and exceptions (call() + check_call())

1 files changed, 48 insertions, 0 deletions

diff --git a/compat.py b/compat.py
index 6010340..0ddf81c 100644
--- a/compat.py
+++ b/compat.py
@@ -9,6 +9,7 @@
 from __future__ import generators
 __docformat__ = "restructuredtext en"
 
+import os
 from warnings import warn
 
 import __builtin__
@@ -241,3 +242,50 @@ except NameError:
             if not elt:
                 return False
         return True
+
+# Python2.5 subprocess added functions and exceptions
+from subprocess import Popen
+class CalledProcessError(Exception):
+    """This exception is raised when a process run by check_call() returns
+    a non-zero exit status.  The exit status will be stored in the
+    returncode attribute."""
+    def __init__(self, returncode, cmd):
+        self.returncode = returncode
+        self.cmd = cmd
+    def __str__(self):
+        return "Command '%s' returned non-zero exit status %d" % (self.cmd,
+self.returncode)
+
+def call(*popenargs, **kwargs):
+    """Run command with arguments.  Wait for command to complete, then
+    return the returncode attribute.
+
+    The arguments are the same as for the Popen constructor.  Example:
+
+    retcode = call(["ls", "-l"])
+    """
+    # workaround: subprocess.Popen(cmd, stdout=sys.stdout) fails
+    # see http://bugs.python.org/issue1531862
+    if "stdout" in kwargs:
+        fileno = kwargs.get("stdout").fileno()
+        del kwargs['stdout']
+        return Popen(stdout=os.dup(fileno), *popenargs, **kwargs).wait()
+    return Popen(*popenargs, **kwargs).wait()
+
+def check_call(*popenargs, **kwargs):
+    """Run command with arguments.  Wait for command to complete.  If
+    the exit code was zero then return, otherwise raise
+    CalledProcessError.  The CalledProcessError object will have the
+    return code in the returncode attribute.
+
+    The arguments are the same as for the Popen constructor.  Example:
+
+    check_call(["ls", "-l"])
+    """
+    retcode = call(*popenargs, **kwargs)
+    cmd = kwargs.get("args")
+    if cmd is None:
+        cmd = popenargs[0]
+    if retcode:
+        raise CalledProcessError(retcode, cmd)
+    return retcode