# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
A release-automation toolkit.

Don't use this outside of Twisted.

Maintainer: Christopher Armstrong
"""

import os


# errors

class DirectoryExists(OSError):
"""
Some directory exists when it shouldn't.
"""
pass



class DirectoryDoesntExist(OSError):
"""
Some directory doesn't exist when it should.
"""
pass



class CommandFailed(OSError):
pass



# utilities

def sh(command, null=True, prompt=False):
"""
I'll try to execute C{command}, and if C{prompt} is true, I'll
ask before running it. If the command returns something other
than 0, I'll raise C{CommandFailed(command)}.
"""
print "--$", command

if prompt:
if raw_input("run ?? ").startswith('n'):
return
if null:
command = "%s > /dev/null" % command
if os.system(command) != 0:
raise CommandFailed(command)



def runChdirSafe(f, *args, **kw):
origdir = os.path.abspath('.')
try:
return f(*args, **kw)
finally:
os.chdir(origdir)