Reintroduce RunCommand cleanup and unit tests. Fixed previous issue, and

lib/cros_build_lib.py

 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Common python commands used by various build scripts."""
 
 import inspect
 import os
 import re
 import subprocess
@@ skipping 18 matching lines @@
                exit_code=False, redirect_stdout=False, redirect_stderr=False,
                cwd=None, input=None, enter_chroot=False, num_retries=0):
   """Runs a shell command.
 
   Arguments:
     cmd: cmd to run.  Should be input to subprocess.POpen.  If a string,
       converted to an array using split().
     print_cmd: prints the command before running it.
     error_ok: does not raise an exception on error.
     error_message: prints out this message when an error occurrs.
     exit_code: returns the return code of the shell command.

[sosa, 2011/03/01 19:42:42]

Update docsring perhaps to say returns exit code ... in case of non-zero exit
code does not throw exception

     redirect_stdout: returns the stdout.
     redirect_stderr: holds stderr output until input is communicated.
     cwd: the working directory to run this cmd.
     input: input to pipe into this command through stdin.
     enter_chroot: this command should be run from within the chroot.  If set,
       cwd must point to the scripts directory.
     num_retries: the number of retries to perform before dying
 
   Returns:
     If exit_code is True, returns the return code of the shell command.
@@ skipping 13 matching lines @@
   if redirect_stderr:  stderr = subprocess.PIPE
   if input:  stdin = subprocess.PIPE
   if enter_chroot:  cmd = ['./enter_chroot.sh', '--'] + cmd
 
   # Print out the command before running.
   if print_cmd:
     Info('PROGRAM(%s) -> RunCommand: %r in dir %s' %
          (GetCallerName(), cmd, cwd))
 
   for retry_count in range(num_retries + 1):
-    try:
-      proc = subprocess.Popen(cmd, cwd=cwd, stdin=stdin,
-                              stdout=stdout, stderr=stderr)
-      (output, error) = proc.communicate(input)
-      if exit_code and retry_count == num_retries:
-        return proc.returncode
 
-      if proc.returncode == 0:
-        break
+    # If it's not the first attempt, it's a retry
+    if retry_count > 0 and print_cmd:
+      Info('PROGRAM(%s) -> RunCommand: retrying %r in dir %s' %
+           (GetCallerName(), cmd, cwd))
 
+    proc = subprocess.Popen(cmd, cwd=cwd, stdin=stdin,
+                            stdout=stdout, stderr=stderr)
+    (output, error) = proc.communicate(input)
+
+    # if the command worked, don't retry any more.
+    if proc.returncode == 0:
+      break
+
+  # If they asked for an exit_code, give it to them on success or failure
+  if exit_code:
+    return proc.returncode
+
+  # If the command (and all retries) failed, handle error result
+  if proc.returncode != 0:
+    if error_ok:
+      Warning('Command "%r" failed.\n' % (cmd) +
+              (error_message or error or output or ''))
+    else:
       raise RunCommandException('Command "%r" failed.\n' % (cmd) +
                                 (error_message or error or output or ''))
-    except RunCommandException as e:
-      if not error_ok and retry_count == num_retries:
-        raise e
-      else:
-        Warning(str(e))
-        if print_cmd:
-          Info('PROGRAM(%s) -> RunCommand: retrying %r in dir %s' %
-               (GetCallerName(), cmd, cwd))
 
+  # return final result
   return output
 
 
 def RunCommandCaptureOutput(cmd, print_cmd=True, cwd=None, input=None,
                             enter_chroot=False,
                             combine_stdout_stderr=True,
                             verbose=False):
   """Runs a shell command. Differs from RunCommand, because it allows
      you to run a command and capture the exit code, output, and stderr
      all at the same time.
@@ skipping 153 matching lines @@
   either via a VM or remote machine on the same network.
   """
   ifconfig_output = RunCommand(['/sbin/ifconfig', device],
                                redirect_stdout=True, print_cmd=False)
   match = re.search('.*inet addr:(\d+\.\d+\.\d+\.\d+).*', ifconfig_output)
   if match:
     return match.group(1)
   else:
     Warning('Failed to find ip address in %s' % ifconfig_output)
     return None