Module posix.signal
Software Signal Facilities.
Constants and functions for propagating signals among processes.
 Note that posix.signal.signal is implemented with sigaction(2) for
 consistent semantics across platforms.
Functions
| kill (pid, opt) | Send a signal to the given process. | 
| killpg (pgrp[, sig=`SIGTERM`]) | Send a signal to the given process group. | 
| raise (sig) | Raise a signal on this process. | 
| signal (signum[, handler=SIG_DFL[, flags]]) | Install a signal handler for this signal number. | 
Constants
| posix.signal | Signal constants. | 
Functions
- kill (pid, opt)
- 
    Send a signal to the given process.
    Parameters:- pid int process to act on
- opt
            int
        =SIGTERMsig signal to send
 Returns:- 
           int
        
 0, if successfulOr- nil
- string error message
- int errnum
 See also:
- killpg (pgrp[, sig=`SIGTERM`])
- 
    Send a signal to the given process group.
    Parameters:- pgrp
            int
         group id to act on, or 0for the sending process`s group
- sig int signal to send (default `SIGTERM`)
 Returns:- 
           int
        
 0, if successfulOr- nil
- string error message
- int errnum
 See also:
- pgrp
            int
         group id to act on, or 
- raise (sig)
- 
    Raise a signal on this process.
    Parameters:- sig int signal to send
 Returns:- 
           int
        
 0, if successfulOr- nil
- string error message
- int errnum
 See also:
- signal (signum[, handler=SIG_DFL[, flags]])
- 
    Install a signal handler for this signal number.
Although this is the same API as signal(2), it uses sigaction for guaranteed semantics.
    Parameters:- signum int
- handler
            function
         function, or SIG_IGNorSIG_DFLconstants (default SIG_DFL)
- flags
         the sa_flagselement ofstruct sigaction(optional)
 Returns:- 
           function
        previous handler function
    
 See also:
Constants
- posix.signal
- 
    Signal constants.
Any constants not available in the underlying system will be nilvalued.Fields:- SIGABRT int abort ()
- SIGALRM int alarm clock
- SIGBUS int bus error
- SIGCHLD int to parent on child stop or exit
- SIGCONT int continue a stopped process
- SIGFPE int floating point error
- SIGHUP int hangup
- SIGILL int illegal instruction
- SIGINT int interrupt
- SIGKILL int kill
- SIGPIPE int write on pipe with no reader
- SIGQUIT int quit
- SIGSEGV int segmentation violation
- SIGSTOP int stop
- SIGTERM int terminate
- SIGTSTP int stop signal from tty
- SIGTTIN int to readers process group on background tty read
- SIGTTOU int to readers process group on background tty output
- SIGUSR1 int user defined
- SIGUSR2 int user defined
- SIGSYS int bad argument to system call
- SIGTRAP int trace trap
- SIGURG int urgent condition on i/o channel
- SIGVTALRM int virtual time alarm
- SIGXCPU int exceeded cpu time limit
- SIGXFSZ int exceeded file size limit
- SA_NOCLDSTOP int do not generate a SIGCHLD on child stop
- SA_NOCLDWAIT int don't keep zombies child processes
- SA_RESETHAND int reset to SIG_DFL when taking a signal
- SA_NODEFER int don't mask the signal we're delivering
 Usage:-- Print signal constants supported on this host. for name, value in pairs (require "posix.signal") do if type (value) == "number" then print (name, value) end end