make py lib a self-contained directory again

- move and merge _py/ bits back to py/
- fixes all around

--HG--
branch : trunk

py/impl/process/cmdexec.py

@@ -0,0 +1,44 @@
+"""
+
+"""
+
+import os, sys
+import subprocess
+import py
+from subprocess import Popen, PIPE
+
+def cmdexec(cmd):
+    """ return output of executing 'cmd' in a separate process.
+
+    raise cmdexec.ExecutionFailed exeception if the command failed.
+    the exception will provide an 'err' attribute containing
+    the error-output from the command.
+    """
+    process = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    out, err = process.communicate()
+    out = py.builtin._totext(out, sys.getdefaultencoding())
+    err = py.builtin._totext(err, sys.getdefaultencoding())
+    status = process.poll()
+    if status:
+        raise ExecutionFailed(status, status, cmd, out, err)
+    return out
+
+class ExecutionFailed(py.error.Error):
+    def __init__(self, status, systemstatus, cmd, out, err):
+        Exception.__init__(self)
+        self.status = status
+        self.systemstatus = systemstatus
+        self.cmd = cmd
+        self.err = err
+        self.out = out
+
+    def __str__(self):
+        return "ExecutionFailed: %d  %s\n%s" %(self.status, self.cmd, self.err)
+
+# export the exception under the name 'py.process.cmdexec.Error'
+cmdexec.Error = ExecutionFailed
+try:
+    ExecutionFailed.__module__ = 'py.process.cmdexec'
+    ExecutionFailed.__name__ = 'Error'
+except (AttributeError, TypeError):
+    pass