git.distorted.org.uk Git - u/mdw/putty/blob - unix/uxsignal.c

   1 #include <signal.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4
   5 /*
   6  * Calling signal() is non-portable, as it varies in meaning
   7  * between platforms and depending on feature macros, and has
   8  * stupid semantics at least some of the time.
   9  *
  10  * This function provides the same interface as the libc function,
  11  * but provides consistent semantics.  It assumes POSIX semantics
  12  * for sigaction() (so you might need to do some more work if you
  13  * port to something ancient like SunOS 4)
  14  */
  15 void (*putty_signal(int sig, void (*func)(int)))(int) {
  16     struct sigaction sa;
  17     struct sigaction old;
  18
  19     sa.sa_handler = func;
  20     if(sigemptyset(&sa.sa_mask) < 0)
  21         return SIG_ERR;
  22     sa.sa_flags = SA_RESTART;
  23     if(sigaction(sig, &sa, &old) < 0)
  24         return SIG_ERR;
  25     return old.sa_handler;
  26 }
  27
  28 void block_signal(int sig, int block_it)
  29 {
  30     sigset_t ss;
  31
  32     sigemptyset(&ss);
  33     sigaddset(&ss, sig);
  34     if(sigprocmask(block_it ? SIG_BLOCK : SIG_UNBLOCK, &ss, 0) < 0) {
  35         perror("sigprocmask");
  36         exit(1);
  37     }
  38 }
  39
  40 /*
  41 Local Variables:
  42 c-basic-offset:4
  43 comment-column:40
  44 End:
  45 */