Can Jython help here? Should I run Grails above Jython and if yes, how? Somehow I should be able to run Grails and Python script on same JVM. There are other possibilities like making REST service for Python script or some interprocess communication but lets not deal with those for now.
Jython is a JSR223 scripting language, so you should be able to follow the usual methods. (http://www.jython.org/archive/22/userguide.html#embedding-jython)
ScriptEngine engine = new ScriptEngineManager().getEngineByName("python")
engine.eval("x = 2 + 2")
It might be a non-trivial thing to get your Jython and any libraries you want to use organized on your server, but if all you need is the language and the standard libraries, you should be able to just add it as a dependency in your buildfile - it is on Maven Central (compile 'org.python:jython:2.7.1b3').
But keep in mind that many python libraries (i.e. ones that use compiled C-code) are not going to work with Jython.
So, you might need to instead use a native python installation and call it as a process (using ProcessBuilder, for example). Groovy has some nice sugar for doing this sort of thing with strings.
Process process = "python mypython.py".execute()
An internet search for things like "groovy execute shell command" will yield lots of examples. Depending on your deployment scenario, this could be tricky to set up and maintain.
I'm kinda new to scripting for IDA - nevertheless, I've written a complex script I need to debug, as it is not working properly.
It is composed of a few different files containing a few different classes.
Writing line-by-line in the commandline is not effective for obvious reasons.
Running a whole script from the File doesn't allow debugging.
Is there a way of using the idc, idautils, idaapi not from within IDA?
I've written the script on PyDev for Eclipse, I'm hoping for a way to run the scripts from within it.
A similar question is, can the api classes I have mentioned work on idb files without IDA having them loaded?
Thanks.
Now I may be wrong for I haven't written any IDA script for long time. But as far as I remember the answer to your first question is no. There is the part that loads the IDA script and prepare the whole environment so you could re implement it and create your own environment, however I would not recommend that.
What I can tell you is to consider running your script from command line if automation is what you are aiming for. IDA python (as well as any other IDA plugin) have a good support for running scripts from command line. For performance you can also run the TUI version of IDA.
There is also a hack for that enables you to launch a new python interpreter in the middle of the IDA script. It is useful for debugging a current state yet you will still need to edit the python file every time to launch the interpreter.
Here is the hack:
import code
all = globals()
all.update(locals())
code.interact(local = all)
Anyway - logs are good and debug prints are OK.
Good luck :)
We've just got a notice from one of our users that the latest version of WingIDE supports debugging of IDAPython scripts. I think there are a couple of other programs using the same approach (import a module to do RPC debugging) that might work.
I created a module in Python which provides about a dozen functionalities. While it will be mostly used from within Python, there is a good fraction of legacy users which will be calling it from Perl.
What is the best way to make a plug in to this module? My thoughts are:
Provide the functionalities as command line utilities and make system calls
Create some sort of server and handle RPC calls (say, via JSON RPC)
Any advise?
One other choice is to inline Python directly in your Perl script, using Inline::Python.
This may be simpler than other solutions, and only requires one additional module.
In the short run the easiest solution is to use Inline::Python. Closely followed by calling a command-line script.
In the long run, using a server to provide RPC functionality or simply calling a command-line script will give you the most future proof solution.
Why?
Becuase that way you aren't tied to Perl or Python as the language used to build the systems that consume the services provided by your library. Either method creates a clear, language independent interface that you can use with whatever development environment you adopt.
Depending on your needs any of the presented options may be the "best choice". Depending on how your needs evolve over time, a different choice may be revealed as "best".
My approach to this would be to ask a couple of questions:
How often do you change development tools. You've switched to Python from Perl. Did you start with Tcl and go to Perl? Are you going to switch to the exciting new language X in 1, 5 or 10 years? If you change tools 'often' (whatever that means) emphasize cross tool compatibility.
How fast is fast enough? Is the start up time for command line solutions ok? Does Inline::Python slow things down too much (you are still initializing a Python interpreter, it's just embedded in your Perl interpreter)?
Based on the answers to these questions, I would do the simplest thing that is likely to work.
My guess is that means in order:
Inline::Python
Command line scripts
Build an RPC server
Provide the functionalities as command line utilities and make system calls
Works really nicely. This is the way programs like Python (and Perl) are meant to use used.
I decided to rewrite all our Bash scripts in Python (there are not so many of them) as my first Python project. The reason for it is that although being quite fluent in Bash I feel it's somewhat archaic language and since our system is in the first stages of its developments I think switching to Python now will be the right thing to do.
Are there scripts that should always be written in Bash? For example, we have an init.d daemon script - is it OK to use Python for it?
We run CentOS.
Thanks.
It is OK in the sense that you can do it. But the scripts in /etc/init.d usually need to load config data and some functions (for example to print the nice green OK on the console) which will be hard to emulate in Python.
So try to convert those which make sense (i.e. those which contain complex logic). If you need job control (starting/stopping processes), then bash is better suited than Python.
Generally, scripts in /etc/init.d are written in the "native shell" of the OS (e.g. bash, sh, posix-sh, etc). This is especially true of scripts that will be run at the lower init levels (e.g. not every directory will be mounted in single user mode, including wherever python or the site-libraries might be installed).
Most OS's provide some "helper functions" that make writing scripts in some native shell easier. These scripts define certain return codes and messages that are required/desired when writing service scripts. On RedHat based systems, see:
/etc/init.d/functions
Beyond that, the service scripts in /etc/init.d can be written in any language (including compiled languages). The general calling syntax will need to be supported. Typically there are three arguments that should be supported: start, stop, and status. Some additional arguments might be appropriate, depending on the purpose of the scripts.
% /etc/init.d/foo (start|stop|status)
Every task has languages that are better suited for it and less so. Replacing the backtick ` quote of sh is pretty ponderous in Python as would be myriad quoting details, just to name a couple. There are likely better projects to cut your teeth on.
And all that they said above about Python being relatively heavyweight and not necessarily available when needed.
Certain scripts that I write simply involving looping over a glob in some directories, and then executing some a piped series of commands on them. This kind of thing is much more tedious in python.
I've got some experience with Bash, which I don't mind, but now that I'm doing a lot of Windows development I'm needing to do basic stuff/write basic scripts using
the Windows command-line language. For some reason said language really irritates me, so I was considering learning Python and using that instead.
Is Python suitable for such things? Moving files around, creating scripts to do things like unzipping a backup and restoring a SQL database, etc.
Python is well suited for these tasks, and I would guess much easier to develop in and debug than Windows batch files.
The question is, I think, how easy and painless it is to ensure that all the computers that you have to run these scripts on, have Python installed.
Summary
Windows: no need to think, use Python.
Unix: quick or run-it-once scripts are for Bash, serious and/or long life time scripts are for Python.
The big talk
In a Windows environment, Python is definitely the best choice since cmd is crappy and PowerShell has not really settled yet. What's more Python can run on several platform so it's a better investment. Finally, Python has a huge set of library so you will almost never hit the "god-I-can't-do-that" wall. This is not true for cmd and PowerShell.
In a Linux environment, this is a bit different. A lot of one liners are shorter, faster, more efficient and often more readable in pure Bash. But if you know your quick and dirty script is going to stay around for a while or will need to be improved, go for Python since it's far easier to maintain and extend and you will be able to do most of the task you can do with GNU tools with the standard library. And if you can't, you can still call the command-line from a Python script.
And of course you can call Python from the shell using -c option:
python -c "for line in open('/etc/fstab') : print line"
Some more literature about Python used for system administration tasks:
The IBM lab point of view.
A nice example to compare bash and python to script report.
The basics.
The must-have book.
Sure, python is a pretty good choice for those tasks (I'm sure many will recommend PowerShell instead).
Here is a fine introduction from that point of view:
http://www.redhatmagazine.com/2008/02/07/python-for-bash-scripters-a-well-kept-secret/
EDIT: About gnud's concern: http://www.portablepython.com/
Are you aware of PowerShell?
Anything is a good replacement for the Batch file system in windows. Perl, Python, Powershell are all good choices.
#BKB definitely has a valid concern. Here's a couple links you'll want to check if you run into any issues that can't be solved with the standard library:
Pywin32 is a package for working with low-level win32 APIs (advanced file system modifications, COM interfaces, etc.)
Tim Golden's Python page: he maintains a WMI wrapper package that builds off of Pywin32, but be sure to also check out his "Win32 How Do I" page for details on how to accomplish typical Windows tasks in Python.
Python is certainly well suited to that. If you're going down that road, you might also want to investigate SCons which is a build system itself built with Python. The cool thing is the build scripts are actually full-blown Python scripts themselves, so you can do anything in the build script that you could otherwise do in Python. It makes make look pretty anemic in comparison.
Upon rereading your question, I should note that SCons is more suited to building software projects than to writing system maintenance scripts. But I wouldn't hesitate to recommend Python to you in any case.
As a follow up, after some experimentation the thing I've found Python most useful for is any situation involving text manipulation (yourStringHere.replace(), regexes for more complex stuff) or testing some basic concept really quickly, which it is excellent for.
For stuff like SQL DB restore scripts I find I still usually just resort to batch files, as it's usually either something short enough that it actually takes more Python code to make the appropriate system calls or I can reuse snippets of code from other people reducing the writing time to just enough to tweak existing code to fit my needs.
As an addendum I would highly recommend IPython as a great interactive shell complete with tab completion and easy docstring access.
I've done a decent amount of scripting in both Linux/Unix and Windows environments, in Python, Perl, batch files, Bash, etc. My advice is that if it's possible, install Cygwin and use Bash (it sounds from your description like installing a scripting language or env isn't a problem?). You'll be more comfortable with that since the transition is minimal.
If that's not an option, then here's my take. Batch files are very kludgy and limited, but make a lot of sense for simple tasks like 'copy some files' or 'restart this service'. Python will be cleaner, easier to maintain, and much more powerful. However, the downside is that either you end up calling external applications from Python with subprocess, popen or similar. Otherwise, you end up writing a bunch more code to do things that are comparatively simple in batch files, like copying a folder full of files. A lot of this depends on what your scripts are doing. Text/string processing is going to be much cleaner in Python, for example.
Lastly, it's probably not an attractive alternative, but you might also consider VBScript as an alternative. I don't enjoy working with it as a language personally, but if portability is any kind of concern then it wins out by virtue of being available out of the box in any copy of Windows. Because of this I've found myself writing scripts that were unwieldy as batch files in VBScript instead, since I can't usually depend on Python or Perl or Bash being available on Windows.
Python, along with Pywin32, would be fine for Windows automation. However, VBScript or JScript used with the Windows Scripting Host works just as well, and requires nothing additional to install.
I've been using a lot of Windows Script Files lately. More powerful than batch scripts, and since it uses Windows scripting, there's nothing to install.
As much as I love python, I don't think it a good choice to replace basic windows batch scripts.
I can't see see someone having to import modules like sys, os or getopt to do basic things you can do with shell like call a program, check environment variable or an argument.
Also, in my experience, goto is much easier to understand to most sysadmins than a function call.