im willing to create a project same as JUNOS cli or cisco cli,
I came through gnu readline, but im confused as there are too many functions and methods to implement. any how i want a cli with auto complete using tab and space bar with question mark to display commands with help text.
I have two questions :
I have found code in python and perl but the im not use to python that code is complete and i just want to know if i should continue with python. im more experienced in perl but the code i found so far isn't complete for perl.
readline.parse_and_bind('tab: complete')
should i use the same complete function for both help and autocomplete feature. where as i have gone through another function
readline.set_completion_display_matches_hook(print_suggestions)
what you suggest :P im completely new to it!
I must say that I struggle to understand which specific point you are addressing in your question. But here is a suggestion anyway:
Start out with the cmd module. It gives you a nice little framework to build a command-line interpreter. It supports tab completion out of the box (provided readline is available). Start implementing your command-line interface. Once this stabilizes you can think about adding more comfort, e.g. tab completion for command arguments, help keys, and the like. This way, you have a working app to deal with, and can address readline details more specifically when you really need them. I wouldn't wade through the whole readline API upfront, if I were in your shoes.
We had to create a cli like JunOS/Cisco/VyOS and we built it on top of ishell, which uses readline for this job.
From the project page:
ishell helps you to easily create an interactive shell for your application. It supports command completion, dynamic arguments, a command history, and chaining of commands.
You can check the project at github: https://github.com/italorossi/ishell
Cisco example:
PS: I'm the author :).
Related
So, I recently made a Python program that I want to send to someone with them being able to execute it, but not read the code I have typed in it. Any ideas how to do it?
BTW, I want it to be irreversible
In short, here are my Parameters:
Should remain a Python file
Can't be reversed
Code should not be readable
Should still have the ability to be run
The criteria you've posted are inconsistent.
Python is an interpreted language. The entity running the language (i.e. Python interpreter) is reading your code and executing it, line by line. If you wrap it up to send to someone, their Python interpreter must have read permissions on the file, whether it's source code or "compiled" Python (which is easily decompiled into equivalent source code).
If we take a wider interpretation of "send to someone", there may be a business solution that serves your needs. You would provide your functionality, rather than the code: deploy it as a service from some available server: your own, or rented space. To do this, you instead provide an interface to your functionality.
If this fulfills your needs, you now have your next research topic.
I've done a bit of research and I've played with different graphical kits and was wondering if there was a way to display a native windows command line in my application. So, it'd be something like the command line in Jetbrains products (I think eclipse has one too), but the goal is to have 4 of them.
I've found a piece of linux software demonstrating the core concept of what I want to do and I've attached it at the bottom. Basically, I just want four terminals, and I'm going to have the app handle specific key bindings for "ease of access" tasks. I've used the linked software before and like it, but I thought as I'm exploring python it'd be a good learning experience to write something like this for windows as well!
Thanks in advance!
Edit - Google searching "Windows Tkinter Command Line" and the likes haven't been fruitful :) I promise I googled a LOT before posting here.
I dont know if there is anything readymade for this. Basically, you will need to have a text widget and simulate the output with the subprocess module to directly pass user input to run system commands and append results to the same text widget. You could also consider two windows - one for text input and one for result output.
Here is a link: Calling an external command in Python
Hello Python developers!
I'm a Java one and I know that there is a way of running Java code on the fly, but my question is, is there any way to do that with Python?
The main goal here is to enable middle-school students to start coding with chromebooks from day one on Python.
I've been looking for some resources, but I got nothing so far.
Thanks a lot!
http://shell.appspot.com might be of your interest. (there's a link to the source code too)
Hey, I just recovered a link to a nice page I used in the past. It shows the execution flow of a Python script. Students I taught found it very useful in terms of comparing with other languages they new already, e.g. Java, how stack and arguments are being passed to the functions, memory allocations, etc:
http://people.csail.mit.edu/pgbovine/python/tutor.html
(click on "Visualize execution" button beneath the window with the code)
IPython allows you to run python interactively from a web environment. You can try a demo here: IPython. You can set this up on a local computer and have you students view it from their machines.
Coderbuddy let's you create and run AppEngine applications online, without having to download the AppEngine SDK, Python, or anything for that matter.
I use that when I do workshops, so I don't have to bother with making sure that everyone has the SDK and proper configurations in their machines. We just go straight to coding. :)
Imagine a web application that allows a logged in user to run a shell command on the web server at the press of a button. This is relatively simple in most languages via some standard library os tools.
But if that command is long running you don't want your UI to hang. Again this is relatively easy to deal with using some sort of background process or putting the command to be executed onto a message queue (and maybe saving the output and status somewhere for later consumption). Just return quickly saving we'll run that and get back to you.
What I'd like to do is show the output of said web ui triggered shell command as it happens. So vertically scrolling text like when running in a terminal.
I have a vague idea of how I might approach this, streaming the output to a websocket perhaps and simply printing the output to screen.
What I'd like to ask is:
Are their any plugins, libraries or applications that already do this. Something I can either use or read the source of. Ideally an open source python/django or ruby/rails tool, but other stacks would be interesting too.
I'm not sure if it's what you want, but there are some web based ssh clients out there. If you care about security and really just want dynamic feedback, you could look into comet or just have a frame with its own http session that doesn't end until it's done printing.
web-based ssh client would work, into the host (there are java ssh clients out there).
Ruby has a web-based terminal:
http://tryruby.org (link to the source is at the bottom of the page).
You could also embed Ruby via jruby: http://tim.lossen.de/2007/03/jruby/applet.html
http://github.com/jruby/jruby/blob/master/samples/irb-applet.html
I haven't heard of any libraries that do this, but you'll need to setup the system command and call out to the system. You will then need to "pump" the sysout and syserr standard inputs and pipe that data back out to your web client.
As an example for this style of problem, look into code snippits of how people use ruby/python/etc to transcode a video, i.e. http://kpumuk.info/ruby-on-rails/encoding-media-files-in-ruby-using-ffmpeg-mencoder-with-progress-tracking/ - my example was taken from this blog post.
class MediaFormatException < StandardError
end
def execute_mencoder(command)
progress = nil
IO.popen(command) do |pipe|
pipe.each("r") do |line|
if line =~ /Pos:[^(]*(s*(d+)%)/
p = $1.to_i
p = 100 if p > 100
if progress != p
progress = p
print "PROGRESS: #{progress}n"
$defout.flush
end
end
end
end
raise MediaFormatException if $?.exitstatus != 0
end
I don't know if this example is pulling data from both sysout and syserr, but you will definitely need to be pulling data from both of those interfaces, typically if the buffer fills up, the executing command might hang or fail (I have experienced this with Python). This method will also look different if the only thing you do is return line to the web client - in a terminal, the progress indicator of ffmpeg/mencoder remains stationary on the bottom line, but this method will give you a long list of progress indicator updates. Pipe line out to your terminal and you'll see what I'm referring to.
So, I've tried to answer my own question with code as I couldn't find anything to quite fit the bill. Hopefully it's useful to anyone coming across the same problem.
Redbeard 0X0A pointed me in the general direction, I was able to get a stand along ruby script doing what I wanted using popen. Extending this to using EventMachine (as it provided a convenient way of writing a websocket server) and using it's inbuilt popen method solved my problem.
More details here http://morethanseven.net/2010/09/09/Script-running-web-interface-with-websockets.html and the code at http://github.com/garethr/bolt/
Certainly not the best way to run shell commands, but likely the easiest:
#!/bin/sh
echo Content-Type: text/plain
echo
/usr/bin/uptime
http://www.sente.cc/scripts/uptime.cgi
Take a look at Galaxy (online demo) or Yabi.
Except from the requirement to be able to show output during the job run, they are both excellent solutions to this! They are also both written i Python (and Yabi even on django).
They were both built with bioinformatics in mind, but really are both general job runner/workflow tools.
They will let you specify parameters in a web interface, see queued/running/finished jobs in a separate column, and after the jobs are finished, inspect details and results, or re-run the job, with possibly changed parameters.
Galaxy is the easier one to install. The Galaxy installation boils down to downloading and run "sh run.sh"), and adding your own tool boils down to creating an XML file in the line of:
<tool id="mytool" name="My Tool" version="1.0.0">
<description>Does this and that</description>
<command>somecommand --aparam $aparam</command>
<inputs>
<param name="aparam" type="text" label="A parameter"/>
</inputs>
<outputs>
<data name="outfile" format="tabular"/>
</outputs>
</tool>
... and place it in the /tools folder, and add a line in the tool_conf.xml to tell galaxy of your new tool (There you can also get rid of the bioinformatics-tools, so they don't mess up your tools menu).
Yabi is more complicated to install (see the readme file), but the process might be smooth if you are on the right kind of system. On the other hand, it allows you even do the tool configuration in the web interface, rather than as an XML file like in Galaxy.
Galaxy still is the one with the biggest community though, which is reflected in the number of features/already integrated tools (See the toolshed for shared tools/wrapper).
websocketd looks like the perfect tool for that.
I'm planning to develop a GUI application that uses curses. The idea is to provide an extra interface for a web interface, so that everything on the web site could also be done via the UI.
Basically, it should be platform independent: the user would have to SSH to the server after which the UI would automatically take over.
First of all, is this doable? As far as I understand, it would be platform independent as long as the end-user had the proper terminal software installed. Correct me, if I'm wrong.
I was planning to use Python for this, as it is the language I'm the most proficient in. Python comes with the ncurses library and Urwid, which I've been told, is quite good.
After having a quick test with Urwid, I had some problems. The thing is, I'm quite worried that I won't find answers to the problems that I will encounter down the road because apparently curses UI-s aren't all the rage nowadays. Documentation and examples are thus quite scarce.
In conclusion, should really I embark on this and quit my whining or drop the idea altogether? Any other suggestions?
It's certainly possible, and curses-based applications are still written regularly (e.g. PuDB is only 14 months old) although maybe not very often.
Did you try asking questions on the Urwid mailing list and/or IRC channel?
oh my, wouldn't this be a dream!
i've seen a couple of things out there to varying degrees of success.
Morticious Thrind: http://thrind.xamai.ca/
future death toll: http://f-dt.com/?wptheme=wp-cli
wordpress yadda yadda, this could be as simple as a 960/blueprint CSS, prototype.js, and a oneliner:
//TODO: Implement useful functionality && unit tests && documentation
//TODO: read
try { eval($F(x)); } catch (e) { panic(); }
BUT! this type of thing is pretty radical. i mean- ANYTHING can happen on the canvas of a web-browser these days, but any terminal emulator or lynx serves this purpose with flare.
also be sure to check out: https://stackoverflow.com/questions/472644/javascript-collection-of-one-line-useful-functions
the real question is what sort of software you plan on ncursing (sic,pun,etc.)-- it probably already has some rather useful command-line interfaces (sh).
It can be done but it's a struggle. I would recommend improving the web interface. You can use JavaScript to add keyboard shortcuts, for example, which can be very helpful for a faster workflow (see Gmail's interface, for example).