# Gr-display-master install (was Re: Writing text to a QT GUI Window) **URL:** \ **Category:** GNU Radio\ **Created:** [April 20, 2015, 4:47pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634 "2015-04-20T16:47:55Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\ **Post date:** [April 20, 2015, 4:47pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634/1 "2015-04-20T16:47:55Z")
In the gr-display-master README file under “2. Installation” when it states… $cmake -DCMAKE\_INSTALL\_PREFIX= …/ What is meant by “”? gnuradio gets installed across many directories, to which does this refer? Sorry for the noob question, I never had to use -DCMAKE\_INSTALL\_PREFIX before just using gr\_modtool for my own blocks, even copying between systems. On my system, when I sudo make install my own modules, it puts stuff in… /usr/local/lib/cmake/MYMODULE /usr/local/include/MYMODULE /usr/local/lib64 /usr/local/lib64/python2.7/site-packages/MYMODULE usr/local/include/MYMODULE/MYMODULE/swig /usr/local/share/gnuradio/blocks gr-display sounds like a great idea, and I am eager to try it out. John M. removed\_email\_address@domain.invalid ---
**Author:** ![MurphyS\_John](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ce7236/32.png) [@MurphyS\_John](https://www.ruby-forum.com/u/MurphyS_John)\ **Post date:** [April 20, 2015, 4:52pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634/2 "2015-04-20T16:52:24Z")
Hi John - is the top-evel PREFIX into which GR is installed. In your case, this would be /usr/local, so you’d use: {{{ cmake -DCMAKE\_INSTALL\_PREFIX=/usr/local … }}} Hope this helps. - MLD ---
**Author:** ![MurphyS\_John](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ce7236/32.png) [@MurphyS\_John](https://www.ruby-forum.com/u/MurphyS_John)\ **Post date:** [April 20, 2015, 5:15pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634/3 "2015-04-20T17:15:12Z")
Nevermind. Asked around the linux’ers here and it is just the output of “which gnuradio-companion”. On mine that was /usr/local/bin. Thanks. John PS - this Text Sink takes a stream of chars as an input. So I take it the rate at which a block of mine delivers the chars to the scheduler to connect to this has to be a multiple of the existing output rate of my block (guessing I can vectorize the chars coming out and use a Vector to Stream to input them into the Text Sink?). ---
**Author:** ![MurphyS\_John](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ce7236/32.png) [@MurphyS\_John](https://www.ruby-forum.com/u/MurphyS_John)\ **Post date:** [April 20, 2015, 5:56pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634/4 "2015-04-20T17:56:00Z")
Saw the item below on the archive page (I get the digest). And, yes, /usr/local is correct, /usr/local/bin builds but gets runtime errors. So many thanks MLD. Now, the next time I get stuck doing this on some random system in the future, how do I know what that directory location is for the gnuradio install? It looks on the wiki like this is always /usr/local if you did not do something to set a specific custom directory in the gnuradio install process (by PyBombs or build-gnuradio or most of the other methods that are described). Is that the case? ---
**Author:** ![MurphyS\_John](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ce7236/32.png) [@MurphyS\_John](https://www.ruby-forum.com/u/MurphyS_John)\ **Post date:** [April 20, 2015, 6:22pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634/5 "2015-04-20T18:22:16Z")
Execute “gnuradio-config-info --prefix” to see the PREFIX into which GNU Radio was installed. The default PREFIX is /usr/local, yes. - MLD ---
**Author:** ![MurphyS\_John](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ce7236/32.png) [@MurphyS\_John](https://www.ruby-forum.com/u/MurphyS_John)\ **Post date:** [April 20, 2015, 5:53pm UTC](https://www.ruby-forum.com/t/gr-display-master-install-was-re-writing-text-to-a-qt-gui-window/241634/6 "2015-04-20T17:53:17Z")
If you install gnuradio without a CMAKE\_INSTALL\_PREFIX it goes to /usr/local containing many subdirectories. But in some use cases it may be necessary to install into a different directory. On your system the CMAKE\_INSTALL\_PREFIX is /usr/local Am 20.04.2015 um 16:45 schrieb Murphy, John: