i am new to python and am trying to call a c++ function from python, I cam across this answer from Florian Bösch and found it really helpful, i did everything as in the link but i have a small problem which really surprised me, when i run the fooWrapper.py from command prompt it displays the result "hello" but when i run the program from idle by clicking run as module the python shell opens and displays nothing, only action is the cursor moves down as when you press enter. Is this normal or is this a problem???
I use python 2.7.3(32bits),with windows 7 and MInGW complier.
The problem is that IDLE redirects standard input and output, but your C++ function writes to the original standard output and thus IDLE will not show it. If you launch IDLE from a terminal you will see the C++'s output in the terminal.
It's a problem of IDLE, and I doubt that you can do something about it.
If you want to develop something bigger than a really small script you ought to use a different IDE.
Related
I try to ask here if somebody has encountered such a problem.
From time to time, I have a situation: I launch my Qt app on Windows (in debug mode, but I am not sure if it matters) via cmd.exe and then I work with it and then I stop working with it for some time. Then I return it to be focused and very rarely I experience this: the app is Not Responding even though I do not have any logic for it to react on being returned to be focused. Then I wait and wait and noting happens and then I press any key in my cmd.exe, and instead of being killed, my app suddenly wakes up and continues to work, and then I do not experience any problems anymore.
What can be the problem? On Linux I do not experience such a problem. I ask because I cannot trace the problem, as it happens not very often. Also, I am not very good acquainted with Windows. If it was Linux I would use gdp -p and try to see where the app hangs. But what can I do on Windows? Any advice on how to catch this?
UPDATE: I can press any key in my cmd.exe to unfreeze the program.
UPDATE:
It looks like it freezes on one of my debug-printfs:
STACK_TEXT:
: ntdll!NtWriteFile+0x14
: KERNELBASE!WriteFile+0x76
!write_text_ansi_nolock+0x183
!_write_nolock+0x451
!_write_internal+0x377
!__acrt_stdio_flush_nolock+0xc4
!__acrt_stdio_end_temporary_buffering_nolock+0x54
!__acrt_stdio_temporary_buffering_guard::~__acrt_stdio_temporary_buffering_guard+0x28
!<lambda_303760bc4008a2b3ec4768a30b06a80c>::operator()+0x104
!__crt_seh_guarded_call<int>::operator()<<lambda_d854c62834386a3b23916ad6dae2782d>,<lambda_303760bc4008a2b3ec4768a30b06a80c> &,<lambda_4780a7ea4f8cbd2590aec34bd14e2bbf> >+0x35
!__acrt_lock_stream_and_call<<lambda_303760bc4008a2b3ec4768a30b06a80c> >+0x58
!common_vfprintf<__crt_stdio_output::standard_base,char>+0x21a
!__stdio_common_vfprintf+0x5c
!_vfprintf_l+0x3f
!printf+0x58
! MyClass::myfunc -- that executes my handler of the button pressed (which freezes)
Why can be so? I mean it's just a printf writing to cmd.
Here is the answer to my question:
https://stackoverflow.com/a/33883532/4781940
I really have that Select Command Prompt title when the freeze happens.
I am really new to programming (actually trying to get this to work for my 1000 level intro C++ class) so I apologize for bad descriptions and lack of terminology.
I am having trouble getting a "Hello World" program to work on Geany. I have followed the instructions here http://wiki.geany.org/howtos/win32/getting-started , pretty much to the letter. My program gets a successful message when I hit compile/build. When I hit execute the terminal pops up but it is blank.
There is a flashing cursor in the spot where I would expect Hello World to be but instead it is blank, and I cannot type anything in the window. From what I've researched I think it may be a similar problem from here How do you make Execute do anything in Geany? but searches on changing the terminal form to work for windows has not yielded any results.
In fact, I have not found much help for Geany on windows at all, so if there is a better set of software to use that is pretty basic I would be interested, I am only really attached to Geany because that is what we will be using in class (on a Linux operating system)
Thanks for the help!
John
Avast Antivirus does, in fact, cause Geany to fail execution of the program. Windows 10 Pro 64-bit using Geany 1.26 full installer with MinGW. I just shut down shields for 10 mins and this allowed the program to execute.
Thanks.
I have a C++ program that runs nicely and it gives my output in the terminal when it runs, this is handy if the algorithm takes time.
How do I 'cout' the output in a terminal styled div in the browser (doesn't allow user to type into it as an actual terminal)
Alternatively is there a different C++ command to direct output elsewhere other than the terminal window in which it is currently running?
Kind of new to C++ so maybe this is a obvious fix but thanks anyway
I am trying to write up a C++ program for a class using XCode. One of the things I wish to do, is to simply clear the screen. I've looked into how to do this, however the catch is that the code needs to run on both a Windows and Macintosh computer. I've looked at some other similar questions, but none of the answers help me. I know there is no "screen" but I want the system to clear the output window. I know that the command system("clear"); does what I want it to, but when XCode tests the program, instead of clearing the screen it prints TERM Variable not set
I've tried opening up the terminal and typing clear and it does in fact respond the way I want it to, so why doesn't the 'terminal' inside of XCode do the same? I just want to get the output window in XCode to respond to clear the same way that the terminal already does.
Here is something I have already tried;
I went to the terminal and ran echo $TERM, to which the terminal responded xterm-256color. I then went over to XCode and opened the "Scheme" settings, and found an Environment Variables setting under "Arguments". I added a variable (to the blank list) called TERM and gave it value xterm-256color. Upon running the program again, the output displays ¿[H¿[2J in the output window, positioned where the TERM Variable not set used to be printed.
Last thing, as a reminder, I cannot change the source code from the way it is now, or it could cause errors when the program is run on a Windows machine.
It does not work because you are "lying": The terminal in Xcode is not a xterm-256color, but it is dumb terminal. More precise, the display represents a NSTextStorage that collects stdout and/or (depending on target switch) stderr.
A dumb terminal is not able to clean the display. If you want to change this, you can write a plug-in similar to Xcode-Colors what adds the ability to understand ansi color codes.
However, if your requirement that the code simply run at Windows and OSX, you may stick with your solution system("clear"), since it works prefectly in the "normal" OSX terminal.
I've got a program called pgm1 which create a new process using fork.
Then in this process, I launch a new program (pgm2) using the following command:
execv( exec_path_name, argv ).
But the thing is that with this method I've got both output in the same terminal.
I've been searching for a while ans the only solution i found was this one:
Open a new terminal with a system call
Attach my pgm2 to the new terminal using this soft http://blog.nelhage.com/2011/01/reptyr-attach-a-running-process-to-a-new-terminal/comment-page-1/#comment-27264
So my question is really simple, is there a more simple way to do that ?
Thanks in advance !
PS: Distro - Ubuntu 11.10 32bit
I can think of two possible solutions:
Do The Right Thing(TM) and send your output to a file: Each process can use a different file, providing both clear separation of the output and better record-keeping. As a bonus, you are also bound to see a performance improvement - terminal output is computationally expensive, even nowadays...
Execute a terminal emulator with the proper arguments: Most terminal emulators provide a way to execute a specific program in place of the shell. For example xterm:
$ xterm top
This will launch top in an xterm instance, without a shell. Quiting top also terminates the xterm window.
If your terminal emulator of choice supports this, you can use it simply by modifying the arguments passed to execv(). Of course, in this case you will be actually executing the terminal emulator instead of your program, which will then call your own process.
Keep in mind that, depending on the terminal emulator, any open file descriptors may not be passed correctly to your program - the terminal will at least mangle the standard file descriptors.