Merge pull request #2 from microlinux/much-better

microlinux · web-flow · commit 04fab50efa07 · 2016-09-26T22:59:10.000-05:00
Update shell.py
diff --git a/shell.py b/shell.py
@@ -1,18 +1,15 @@
 """Functions for executing one shell command and multiple, concurrent shell commands.
 
 Repository:
-	https://github.com/microlinux/python-shell
+    https://github.com/microlinux/python-shell
 
 Author:
-	Todd Mueller <firstname@firstnamelastname.com>
-  
-Version:
-	2.0 20160926
+    Todd Mueller <firstname@firstnamelastname.com>
 
 License:
-	This program is free software: you can redistribute it and/or modify it
-	under the terms of the GNU General Public License as published by the
-	Free Software Foundation, version 3. See https://www.gnu.org/licenses/.
+    This program is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by the
+    Free Software Foundation, version 3. See https://www.gnu.org/licenses/.
 
 """
 
@@ -28,176 +25,176 @@
 """Namedtuple representing the result of a shell command.
 
 Fields:
-	cmd (str): command executed
-	pid (int): process id
-	retval (int): return value
-	runtime (int): runtime in msecs
-	stdout (str): stdout buffer, horizontal/vertical whitespace stripped
-	stderr (str): stderr buffer, horizontal/vertical whitespace stripped
+    cmd (str): command executed
+    pid (int): process id
+    retval (int): return value
+    runtime (int): runtime in msecs
+    stdout (str): stdout buffer, horizontal/vertical whitespace stripped
+    stderr (str): stderr buffer, horizontal/vertical whitespace stripped
 
 """
 
 def stripper(string):
-	"""Sexily strips horizontal and vertical whitespace from a string.
+    """Sexily strips horizontal and vertical whitespace from a string.
 
-	Args:
-		string (str): string to strip
+    Args:
+        string (str): string to strip
 
-	Returns:
-		str: stripped string
+    Returns:
+        str: stripped string
 
-	"""
+    """
 
-	lines = map(str.strip, string.splitlines())
+    lines = map(str.strip, string.splitlines())
 
-	while lines and not lines[-1]:
-		lines.pop()
+    while lines and not lines[-1]:
+        lines.pop()
 
-	while lines and not lines[0]:
-		lines.pop(0)
+    while lines and not lines[0]:
+        lines.pop(0)
 
-	return '\n'.join(lines)
+    return '\n'.join(lines)
 
 def command(cmd, timeout=10, stdin=None):
-	"""Executes one shell command and returns the result.
+    """Executes one shell command and returns the result.
 
-	Args:
-		cmd (str): command to execute
-		timeout (int): timeout in seconds (10)
-		stdin (str): input (None)
+    Args:
+        cmd (str): command to execute
+        timeout (int): timeout in seconds (10)
+        stdin (str): input (None)
 
-	Returns:
-		CommandResult: result of command
+    Returns:
+        CommandResult: result of command
 
     """
 
-	kill = lambda this_proc: this_proc.kill()
-	pid = None
-	retval = None
-	runtime = None
-	stderr = None
-	stdout = None
-
-	try:
-		start = time.time() * 1000.0
-		proc = subprocess.Popen(shlex.split(cmd),
-		                        stdout=subprocess.PIPE,
-		                        stderr=subprocess.PIPE,
-								stdin=subprocess.PIPE,
-								close_fds=True,
-								shell=False)
-
-		timer = threading.Timer(timeout, kill, [proc])
-
-		timer.start()
-		stdout, stderr = map(stripper, proc.communicate(input=stdin))
-		timer.cancel()
-
-		runtime = int((time.time() * 1000.0) - start)
-	except OSError:
-		retval = 127
-		stderr = 'command not found'
-	except:
-		retval = 255
-		stderr = traceback.format_exc()
-	finally:
-		if retval == None:
-			if proc.returncode == -9:
-				retval = 254
-				stderr = 'command timed out'
-			else:
-				retval = proc.returncode
-
-			pid = proc.pid
-
-	return CommandResult(cmd, pid, retval, runtime, stdout, stderr)
+    kill = lambda this_proc: this_proc.kill()
+    pid = None
+    retval = None
+    runtime = None
+    stderr = None
+    stdout = None
+
+    try:
+        start = time.time() * 1000.0
+        proc = subprocess.Popen(shlex.split(cmd),
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE,
+                                stdin=subprocess.PIPE,
+                                close_fds=True,
+                                shell=False)
+
+        timer = threading.Timer(timeout, kill, [proc])
+
+        timer.start()
+        stdout, stderr = map(stripper, proc.communicate(input=stdin))
+        timer.cancel()
+
+        runtime = int((time.time() * 1000.0) - start)
+    except OSError:
+        retval = 127
+        stderr = 'command not found'
+    except:
+        retval = 255
+        stderr = traceback.format_exc()
+    finally:
+        if retval == None:
+            if proc.returncode == -9:
+                retval = 254
+                stderr = 'command timed out'
+            else:
+                retval = proc.returncode
+
+            pid = proc.pid
+
+    return CommandResult(cmd, pid, retval, runtime, stdout, stderr)
 
 def command_wrapper(args):
-	"""Wrapper used my multi_command to pass command arguments as a list."""
+    """Wrapper used my multi_command to pass command arguments as a list."""
 
-	return command(*args)
+    return command(*args)
 
 def multi_command(cmds, timeout=10, stdins=None, workers=4):
-	"""Executes multiple shell commands concurrently and returns the results.
+    """Executes multiple shell commands concurrently and returns the results.
 
-	If stdins is given, its length must match that of cmds. If commands do
-	not require input, their corresponding stdin field must be None.
+    If stdins is given, its length must match that of cmds. If commands do
+    not require input, their corresponding stdin field must be None.
 
-	Args:
-		cmds (list): commands to execute
-		timeout (int): timeout in seconds per command (10)
-		workers (int): max concurrency (4)
-		stdins (list): inputs (None)
+    Args:
+        cmds (list): commands to execute
+        timeout (int): timeout in seconds per command (10)
+        workers (int): max concurrency (4)
+        stdins (list): inputs (None)
 
-	Returns:
-		CommandResult generator: results of commands in given order
+    Returns:
+        CommandResult generator: results of commands in given order
 
-	"""
+    """
 
-	num_cmds = len(cmds)
+    num_cmds = len(cmds)
 
-	if stdins != None:
-		if len(stdins) != num_cmds:
-			raise RuntimeError("stdins length doesn't match cmds length")
+    if stdins != None:
+        if len(stdins) != num_cmds:
+            raise RuntimeError("stdins length doesn't match cmds length")
 
-	if workers > num_cmds:
-		workers = num_cmds
+    if workers > num_cmds:
+        workers = num_cmds
 
-	for i in xrange(num_cmds):
-		try:
-			stdin = stdins[i]
-		except:
-			stdin = None
+    for i in xrange(num_cmds):
+        try:
+            stdin = stdins[i]
+        except:
+            stdin = None
 
-		cmds[i] = (cmds[i], timeout, stdin)
+        cmds[i] = (cmds[i], timeout, stdin)
 
-	pool = multiprocessing.Pool(processes=workers)
-	results = pool.imap(command_wrapper, cmds)
+    pool = multiprocessing.Pool(processes=workers)
+    results = pool.imap(command_wrapper, cmds)
 
-	pool.close()
-	pool.join()
+    pool.close()
+    pool.join()
 
-	return results
+    return results
 
 def test(single_cmds=['ls -l', 'uptime', 'blargh'],
          multi_cmds=['ls -l', 'uptime', 'ping -c3 -i1 -W1 google.com']):
-	"""Demonstrates command and multi_command functionality.
-
-	Args:
-		single_cmds (list): commands to run one at a time
-		multi_cmds (list): commands to run concurrently
-
-	"""
-
-	print
-	print '-----------------------'
-	print 'Running single commands'
-	print '-----------------------'
-
-	for cmd in single_cmds:
-		result = command(cmd)
-		print
-		print 'cmd: %s' % result.cmd
-		print 'pid: %s' % result.pid
-		print 'ret: %s' % result.retval
-		print 'run: %s' % result.runtime
-		print 'out:'
-		print result.stdout
-		print 'err:'
-		print result.stderr
-
-	print
-	print '-------------------------'
-	print 'Running multiple commands'
-	print '-------------------------'
-
-	for result in multi_command(multi_cmds):
-		print
-		print 'cmd: %s' % result.cmd
-		print 'pid: %s' % result.pid
-		print 'ret: %s' % result.retval
-		print 'run: %s' % result.runtime
-		print 'out:'
-		print result.stdout
-		print 'err:'
-		print result.stderr
+    """Demonstrates command and multi_command functionality.
+
+    Args:
+        single_cmds (list): commands to run one at a time
+        multi_cmds (list): commands to run concurrently
+
+    """
+
+    print
+    print '-----------------------'
+    print 'Running single commands'
+    print '-----------------------'
+
+    for cmd in single_cmds:
+        result = command(cmd)
+        print
+        print 'cmd: %s' % result.cmd
+        print 'pid: %s' % result.pid
+        print 'ret: %s' % result.retval
+        print 'run: %s' % result.runtime
+        print 'out:'
+        print result.stdout
+        print 'err:'
+        print result.stderr
+
+    print
+    print '-------------------------'
+    print 'Running multiple commands'
+    print '-------------------------'
+
+    for result in multi_command(multi_cmds):
+        print
+        print 'cmd: %s' % result.cmd
+        print 'pid: %s' % result.pid
+        print 'ret: %s' % result.retval
+        print 'run: %s' % result.runtime
+        print 'out:'
+        print result.stdout
+        print 'err:'
+        print result.stderr
