I'm trying to write some code against libnotify, but the documentation for perl with libnotify is seriously lacking. So is there something that, as of 2011-08-26, is "better" than libnotify? All I need is to send a notification to the currently logged in user on a Linux machine (Ubuntu specifically).
Gtk2::Notify does seem to lack good documentation, but you can browse through some examples at http://cpansearch.perl.org/src/FLORA/Gtk2-Notify-0.05/examples/ including the basic one:
#!/usr/bin/perl
use strict;
use warnings;
use Gtk2::Notify -init, 'Basic';
my $n = Gtk2::Notify->new('Summary', 'This is some sample content');
$n->show;
In fact this seems pretty cool, I may use it for something soon! Thanks for bringing it to my attention.
Otherwise:
On Linux you can use zenity to send a popup message, and to send it to another user's screen you have to play with some environment variables but it can be done. From Perl I would set the appropriate %ENV values and then just execute system or backtick (``) calls to zenity.
Perhaps start here http://www.cyberciti.biz/tips/spice-up-your-unix-linux-shell-scripts.html
Also from within that link, perhaps libnotify-bin/notify-send would also work, depending on the message you are sending.
perl -E '$ENV{DISPLAY} = ":0.0";`notify-send "Hello World"`;'
From what I searched, when porting an application from Windows to Linux, there's no :(
I'll glad to here if there's.
Update: Indeed I was talking about libinotify and not about libnotify.
As far as I can tell freedesktop specification contains a notification service which can be accessed via dbus.
Here is a link to a perl module for that feature.
Related
I managed to install windows based network printer with python3 on ubuntu.
For better coding, I want to check first if the file with the drivers in it exists after the download. I know it is possible with os.path.isfile or something like that but I would like to do that with subprocess although os will not be supported in the future anymore.
So how do I do it? With subprocess.call or something like that?
to check for a file to be present, You ideally use pathlib, which is the pythonic and portable way to interact with the filesystem.
But to avoid Time of Check to Time of Use Errors (TOCTTOU) You should consider:
Instead of :
if check_printer_present():
# now, after checking the printer is present,
# the printer might go offline
use_printer()
better use:
try:
use_printer()
except PrinterError():
printer_error_cleanup()
see:
https://de.wikipedia.org/wiki/Time-of-Check-to-Time-of-Use-Problem
You might remember that idiom as :
it's better to ask forgiveness than permission
(t is better to act decisively and apologize for it later
than to seek approval to act and risk delay, objections, etc.)
We have a python script that needs to trigger the open of the Microsoft Store. We believe that the easiest way to do that is to use the ms-windows-store:// protocol.
We're currently doing that like this
import subprocess
ret = subprocess.call(["start", "ms-windows-store://pdp/?ProductId=9WZDNCRFHVJL"], shell=True)
Is that the recommended way to do this? I'm not sure if using start is correct here, or if there's something better?
Use os.startfile("ms-windows-store://pdp/?ProductId=9WZDNCRFHVJL"). This calls WINAPI ShellExecuteW directly. If you use subprocess, you have the expense of starting a child process. Plus CMD's start command will first search PATH to find a file that it can execute. Presuming nothing is found (and nothing likely will be, given this name), it hands the request off to ShellExecuteExW to let the OS shell handle it.
What I mean by this is:
I have a program. The end user is currently using it. I submit a new piece of source code and expect it to run as if it were always there?
I can't find an answer that specifically answers the point.
I'd like to be able to say, "extend" or add new features (rather than fix something that's already there on the fly) to the program without requiring a termination of the program (eg. Restart or exit).
Yes, you can definitely do that in python.
Although, it opens a security hole, so be very careful.
You can easily do this by setting up a "loader" class that can collect the source code you want it to use and then call the exec builtin function, just pass some python source code in and it will be evaluated.
Check the package
http://opensourcehacker.com/2011/11/08/sauna-reload-the-most-awesomely-named-python-package-ever/ . It allows to overcome certain raw edges of plain exec. Also it may be worth to check Dynamically reload a class definition in Python
I building my sites on the localhost (runs wamp on windows), and when I upload it to my server, I always get
"Cannot modify header information - headers already sent"
I understand that there shouldn't be any blank lines and everyhing, and usually this works out. but now I need to redirect someone after the header has been sent, how can I make my server act like my localhost ?
i'm using cpanel and WHM:
cPanel 11.25.0-R42399 - WHM 11.25.0 - X 3.9
CENTOS 5.4 x86_64 virtuozzo on vps
I will appreciate any help
In short, you need to prevent PHP from outputting anything to the browser before you get to the point where you want to use the header() function.
This should be done by careful programming practices, of which your 'no blank lines' is one, or by storing PHP's output in an output buffer, and only outputting when you're ready for it.
See the ob_start() and ob_flush() methods. You use ob_start() at the start of your application. This disables output and stores it into a buffer. When you're ready to start outputting, use ob_flush() and PHP will send the buffer's contents to the browser, including the headers that are set till that point. If you don't call ob_flush() then the buffer is output (flushed) at the end of the script.
The reason why it works on your WAMP development environment is most likely that output buffering is already enable by default in the php.ini. Quite often these all-in-one packages enable a default buffer for the first 4k bytes or so. However, it is generally better to explicitly start and flush the buffer in your code, since that forces better coding practices.
Well,
I guess by more thinking and better programing you can manage to keep all redirects before any HTML is written.
This problem solved by the old rules...
#user31279: The quickest and dirtiest way I know of is to use # to suppress the warning, so e.g.
#header('Location: some-other-page.php');
I'm working on an application controller for a program that is spitting text directly to /dev/tty.
This is a production application controller that must be able to catch all text going to the terminal. Generally, this isn't a problem. We simply redirect stdout and stderr. This particular application is making direct calls to echo and redirecting the result to /dev/tty (echo "some text" > /dev/tty). Redirects via my application controller are failing to catch the text.
I do have the source for this application, but am not in a position to modify it, nor is it being maintained anymore. Any ideas on how to catch and/or throw away the output?
screen -D -m yourEvilProgram
should work. Much time passed sinced I used it, but if you need to read some of its output it could even be possible that you could utilize some sockets to read it.
[Added: two links, Rackaid and Pixelbeat, and the home page at GNU]
The classic solution to controlling an application like this is Expect, which sets up pseudo-terminals, does logging, and drives the controlled application from a script. It comes with lots of sample scripts so you can probably just adapt one to fit your needs.
This is what I did in python
import pty, os
pid, fd = pty.fork()
if pid == 0: # In the child process execute another command
os.execv('./my-progr', [''])
print "Execv never returns :-)"
else:
while True:
try:
print os.read(fd,65536),
except OSError:
break
I can't quite determine whether the screen program mentioned by #flolo will do what you need or not. It may, but I'm not sure whether there is a logging facility built in, which appears to be what you need.
There probably is a program out there already to do what you need. I'd nominate sudosh as a possibility.
If you end up needing to write your own, you'll probably need to use a pseudo-tty (pty) and have your application controller sit in between the user's real terminal connection and the the pty device, where it can log whatever you need it to log. That's not trivial. You can find information about this in Rochkind's "Advanced UNIX Programming, 2nd Edn" book, and no doubt other similar books (Stevens' "Advanced Programming in the UNIX Environment" book is a likely candidate, but I don't have a copy to verify that).