signals

How to capture different signals such as SIGINT and SIGTERM in Swift correctly? For example, when people stop my script by pressing Control - C , I want to do some cleanup before terminating it. Dispatch Sources can be used to monitor UNIX signals. Here is a simple example, a Swift 3 translation of the C code in the "Monitoring Signals" section from the Concurrency Programming Guide. import Dispatch // or Foundation signal(SIGINT, SIG_IGN) // // Make sure the signal does not terminate the application. let sigintSrc = DispatchSource.makeSignalSource(signal: SIGINT, queue: .main) sigintSrc

Here is the code on which I set my handler for SIGABRT signal then I call abort() but handler does not get trigered, instead program gets aborted, why? #include <iostream> #include <csignal> using namespace std; void Triger(int x) { cout << "Function triger" << endl; } int main() { signal(SIGABRT, Triger); abort(); cin.ignore(); return 0; } PROGRAM OUTPUT: As others have said, you cannot have abort() return and allow execution to continue normally. What you can do however is protect a piece of code that might call abort by a structure akin to a try catch. Execution of the code will be aborted

When using Pro*C (a embedded SQL preprocessor from Oracle for C-Code) or OCI I noticed that the connect/init routine installs some signal handlers. That means before a EXEC SQL CONNECT :username IDENTIFIED BY :password USING :dbspec ; or a OCIEnvNlsCreate() I can verify that for example those signals have following handlers: No NAME Pointer SA_SIGINFO SIG_DFL SIG_IGN ――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――― 1 SIGHUP (nil) false true false 2 SIGINT (nil) false true false 3 SIGQUIT (nil) false true false 4 SIGILL (nil) false true false 5 SIGTRAP (nil) false

Before I begin, I want to clarify that this is not a command-line tool, but an application that accepts commands through it's own command-line interface. Edit: I must apologize about my explanation from before, apparently I didn't do a very good job at explaining it. One more time... I am building a command-line interface application that accepts commands from a user. I have a signal handler setup to catch the signals, which then sets a flag that I need to terminate the application. The problem I'm having is all of the console functions I can find are blocking, which means that I can't detect

As per the title. Can I use std::atomic<> in a signal handler or does sig_atomic_t provide other compiler features? n3376 1.9/6 When the processing of the abstract machine is interrupted by receipt of a signal, the values of objects which are neither — of type volatile std::sig_atomic_t nor — lock-free atomic objects (29.4) are unspecified during the execution of the signal handler, and the value of any object not in either of these two categories that is modified by the handler becomes undefined. Lock-free 29.4/1,2 The ATOMIC_..._LOCK_FREE macros indicate the lock-free property of the

From the question: Is it good programming practice to use setjmp and longjmp in C? Two of the comments left said: "You can't throw an exception in a signal handler, but you can do a longjmp safely -- as long as you know what you are doing. – Dietrich Epp Aug 31 at 19:57 @Dietrich: +1 to your comment. This is a little-known and completely-under-appreciated fact. There are a number of problems that cannot be solved (nasty race conditions) without using longjmp out of signal handlers. Asynchronous interruption of blocking syscalls is the classic example." I was under the impression that signal

How does the compiler or OS distinguish between sig_atomic_t type and a normal int type variable, and ensures that the operation will be atomic? Programs using both have same assembler code. How extra care is taken to make the operation atomic? sig_atomic_t is not an atomic data type. It is just the data type that you are allowed to use in the context of a signal handler, that is all. So better read the name as "atomic relative to signal handling". To guarantee communication with and from a signal handler, only one of the properties of atomic data types is needed, namely the fact that read and

There are a few questions on this already, but nothing in them seems to provide accurate results. I need to determine simply if the phone is connected to a cell network at a given moment. http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Reference/CTCarrier/Reference/Reference.html This class seems to be documented incorrectly, returning values for mobileCountryCode, isoCountryCode and mobileNetworkCode where no SIM is installed to the phone. carrierName indicates a 'home' network or a previous home network if the phone has been unlocked. I also looked up and found some