signals

问题 I am trying to add add some data to the database as soon as tables are created, using the post_syncdb signal. signals.post_syncdb.connect(init) Then in the init function, I want to set permission, so I use ct = ContentType.objects.get(app_label='news', model='Article') Permission(name='Approve articles', codename='can_approve_article', content_type=ct) But if I drop all the tables and run syncdb , I get ... File "...\base\functions\init.py", line 11, in init ct = ContentType.objects.get(app

问题 I'm facing a weird issue regarding sending signal 9 (SIGKILL) to the init process (PID 1). As you may know, SIGKILL can't be ignored via signal handlers. As I tried sending SIGKILL to init, I noticed that nothing was happening; init would not get terminated. Trying to figure out this behaviour, I decided to attach myself to the init process with strace too see more clearly what was happening. Now comes the weird part. If I'm "looking" at the init process with strace and send it SIGKILL, the

问题 I have an object that should signal that a value has changed by emitting a signal with the new value as an argument. The type of the value can change, and so I'm unsure of how to write the signal type. I know that I can acconmplish this using old-style signals like this: self.emit(SIGNAL("valueChanged(PyQt_PyObject)"), newvalue) but how would I write this using new-style signals? I am aware of a previous question related to this but no "real" answer was given there. 回答1: First, the object you

问题 man signal.h indicates there's no SIGEXIT in Solaris 11. How can I trap it in my shell scripts? Or how can I simulate the old behavior of traping SIGEXT? 回答1: Why are you looking to the C API manual for a shell feature ? You definitely can trap the SIGEXIT signal under Solaris 11 shells (at least ksh93, bash and sh). $ cat /etc/release Oracle Solaris 11.1 X86 Copyright (c) 1983, 2012, Oracle and/or its affiliates. All rights reserved. Assembled 19 September 2012 $ cat /tmp/z #!/bin/ksh trap

问题 I have a two column array of data. First column is time (date in decimal years) and second column is the signal strength. The plot is a triangle wave or should be ideally because the sampling is irregularly timed. I've tried numerous methods to get the period of the wave, including fitting a sine wave to the data via lsqcurvefit, but it doesn't always return the right period. Using OCTAVE how do I get the period (my main aim) of this/any irregularly-spaced time series?See plot 回答1: Found

问题 Original post: MATLAB scrolling plot I got a second part in my problem now. As before, I have a 19*1000*134 matrix that I'm plotting thanks to the nicely answer from Aero Engy on the last post. I would like to create in my workspace a vector called clean that will have a 134 length. By default, the value for clean(i) (with i between 1 and 134) will be 1 -- but, if I press a button on the UI interface, the value must get to 0. My code bellow, just don't give me any ouput. The button seems to

问题 I try to catch a termination signal to my code to write a restart file before exiting. My solution is based on this answer. #include <exception> #include <csignal> #include <iostream> class InterruptException : public std::exception { public: InterruptException(int _s) : signal_(_s) { } int signal() const noexcept { return this->signal_; } private: int signal_; }; /// method to throw exception at signal interrupt void sig_to_exception(int s) { throw InterruptException(s); } int main() { //

问题 Note: this is a general question (not limited to wolfram command, and you don't have to know about wolfram ). I consider wrapping wolfram (CUI calculator like python interpreter). Without any wrapper, SIGINT causes the program to suspend the calculation. $ /usr/bin/wolfram -noinit In[1] := While[True, 1] #start infinite loop #execute `kill -SIGINT` from another shell to send SIGINT Interrupt> #calculation now interrupted (you can cancel or resume it) However, with a wrapper, SIGINT causes

问题 I am working on writing a shell, but I want to have stubbed signal handlers when the user hits i.e. control-C or control-Z. My code is as follows; as I have investigated it, I can get it to not stop on a control-Z, but still suspend on a control-Z. The most recent published version of the code is at http://JonathansCorner.com/cjsh/download.cgi. The code I am working on is: def handle_signal(signal_number, frame): print (''' CJSH does not support the traditional and rather archaic methods of

问题 https://en.wikipedia.org/wiki/Unix_signal says Signals are a limited form of inter-process communication used in Unix, Unix-like, and other POSIX-compliant operating systems. A signal is an asynchronous notification sent to a process or to a specific thread within the same process in order to notify it of an event that occurred. ... The kernel can generate signals to notify processes of events. For example, SIGPIPE will be generated when a process writes to a pipe which has been closed by the