[pyside] Implement a "tail -f" solution using QTextBrowser

martinbach

I'd like to show on my QTextBrowser the current content of a log text file (i.e. /var/log/syslog) like I usually use to see when typing "tail -f /var/log/syslog" on a terminal.

Is there a way to obtain such a result on a QTextBrowser ?

@def tail_syslog(self):
filename = '/var/log/syslog'
f = subprocess.Popen(['tail','-F',filename], stdout=subprocess.PIPE,stderr=subprocess.PIPE)
p = select.poll()
p.register(f.stdout)

    while True:
        if p.poll(1):
            self.textBrowser_SYSLOG.insertPlainText(f.stdout.readline())

print f.stdout.readline()

        time.sleep(1)

@

If I use something like the above code my MainWindows doesn't show anymore.

Could you help me ?

andreyc

tail_syslog(self) does not return control to Qt. If it is running in a main thread then Qt does not have a chance to display anything.

I would suggest to run tail_syslog() in separate thread and emit a signal each time when new data arrived. Catch this signal a main thread and display data that comes whith the signal.

SGaist

Hi,

What about QProcess ?

martinbach

Do you have any link where I can study more about what you suggest ?
I'm really a newby.

[quote author="andreyc" date="1397920871"]tail_syslog(self) does not return control to Qt. If it is running in a main thread then Qt does not have a chance to display anything.

I would suggest to run tail_syslog() in separate thread and emit a signal each time when new data arrived. Catch this signal a main thread and display data that comes whith the signal.[/quote]

andreyc

Frankly speaking I don't know. Just copule articles that I've read about QThread.
"Here":http://qt-project.org/wiki/Threads_Events_QObjectsis
Another "good article on QThread":http://mayaposch.wordpress.com/2011/11/01/how-to-really-truly-use-qthreads-the-full-explanation/

And of course the books.
Although most of the "books":http://qt-project.org/books are for Qt4 there is no big changes in QThread between Qt 4 and 5