Which (untrapped) signals will cause a Perl program to stop executing?

What signals will cause a Perl program to stop running if their %SIG entries are not explicitly set?开发者_如何学Go

The answer is platform dependent. To see the default behavior of each signal on your own system, download the Signals::XSIG module (you don't need to install it) and run the program spike/analyze_default_signal_behavior.pl (with no arguments). Or just download and run the script from here.

Note that some signals cannot be trapped by your program even if you do install a %SIG handler. This is also system dependent but usually includes at least SIGKILL and SIGSTOP.

It is easier to talk about the ones that won't stop your program. On my machine (RHEL), everything but FPE (floating point exception), CHLD (child status change), CONT (continue process), URG (urgent condition on socket), and WINCH (window size change) cause the Perl program to stop executing.

Four of the signals don't cause the program to exit, but temporarily cause the program to stop execution: STOP (stop, unblockable), TSTP (terminal stop), and TTIN (Background read from tty), TTOU (Background write to tty). The program will start running again if it recieves CONT.

From man kill on Debian,

   Name     Num   Action    Description
   0          0   n/a       exit code indicates if a signal may be sent
   ALRM      14   exit
   HUP        1   exit
   INT        2   exit
   KILL       9   exit      cannot be blocked
   PIPE      13   exit
   POLL           exit
   PROF           exit
   TERM      15   exit
   USR1           exit
   USR2           exit
   VTALRM         exit
   STKFLT         exit      might not be implemented
   PWR            ignore    might exit on some systems
   WINCH          ignore
   CHLD           ignore
   URG            ignore
   TSTP           stop      might interact with the shell
   TTIN           stop      might interact with the shell
   TTOU           stop      might interact with the shell
   STOP           stop      cannot be blocked
   CONT           restart   continue if stopped, otherwise ignore
   ABRT       6   core
   FPE        8   core
   ILL        4   core
   QUIT       3   core
   SEGV      11   core
   TRAP       5   core
   SYS            core      might not be implemented
   EMT            core      might not be implemented
   BUS            core      core dump might fail
   XCPU           core      core dump might fail
   XFSZ           core      core dump might fail