signals

Here I'm trying to get an user input with getline . Upon receiving an interrupt ^C I want it to signal getline to stop and resume with my program instead of terminating it. I tried to write a newline to stdin but apparently that doesn't work. fwrite("\n", 1, 1, stdin); So what would be a way to achieve this? Assuming your code resembles this: int main(int argc, char **argv) { //Code here (point A) getline(lineptr, size, fpt); //More code here (point B) } Include <signal.h> and bind SIGINT to a handler function f . #include <signal.h> //Declare handler for signals void signal_handler(int signum

For my GUI i would like to have two pairs of buttons that scroll up and down a scrollarea. The first set of buttons should work on say scrollarea1 and the second set of buttons should work on a scrollarea2. The widgets that I put in the scrollarea are called viewport1 and viewport2. Since both both set of buttons should do the same (scrolling up and down) I thought I would make two slots called scrollUp and scrollDown that would handle the scrolling for both sets of buttons. Unfortunately I cannot make this work and need some help. I have tried the following: QPushButton up; QPushButton down;

According to the documentation : There is no way to “block” signals temporarily from critical sections (since this is not supported by all Unix flavors). What stops me using signal.signal(signum,SIG_IGN) to block it, then adding the signal back? What stops you is that, if the signal actually arrives while SIG_IGN is in place, then it will be ignored and thrown away. When you add the signal back later, it's too late because it's gone and you'll never get to learn that it happened. Thus, you will have "ignored" (= thrown away) the signal rather than "blocked" it (= kept it for handling at the

The following is my code. Parent forks a child. Child pause until parent sends a signal to it, then it continues running. My question is why doesn't child process continue running after parent sending signal to him. Did I miss or misunderstand something? #include<stdio.h> #include<unistd.h> #include<signal.h> void sigusr1( int pidno ) { printf("Catched\n"); } int main() { pid_t pid; signal( SIGUSR1, sigusr1 ); if( (pid = fork()) == 0 ){ pause(); printf("Child\n"); } kill( pid , SIGUSR1 ); //parent sends signal to child pause(); } Here's what happens in the parent: Fork a child. Send SIGUSR1 to