[Next] [Up] [Previous]
Next: SigProcMask Up: Functions and procedures Previous: Dup2

SigAction

   

Declaration:

Procedure SigAction (Signum : Integer; Var Act,OldAct : PSigActionRec) ;

Description:

Changes the action to take upon receipt of a signal. Act and Oldact are pointers to a SigActionRec record.

SigNum specifies the signal, and can be any signal except SIGKILL or SIGSTOP.

If Act is non-nil, then the new action for signal SigNum is taken from it. If OldAct is non-nil, the old action is stored there.

Sa_Handler may be SIG_DFL for the default action or SIG_IGN to ignore the signal.

Sa_Mask Specifies which signals should be ignord during the execution of the signal handler.

Sa_Flags Speciefies a series of flags which modify the behaviour of the signal handler. You can 'or' none or more of the following :

SA_NOCLDSTOP
If signum is SIGCHLD do not receive notification when child processes stop.
SA_ONESHOT or SA_RESETHAND
Restore the signal action to the default state once the signal handler has been called.
SA_RESTART
For compatibility with BSD signals.
SA_NOMASK or SA_NODEFER
Do not prevent the signal from being received from within its own signal handler.

Errors:

LinuxError is used to report errors.

sys_einval
an invalid signal was specified, or it was SIGKILL or SIGSTOP.
sys_efault
Act,OldAct point outside this process address space
sys_eintr
System call was interrupted.

See also:

SigProcMask, SigPending, SigSuspend, Kill, Sigaction(2)



Michael Van Canneyt
Thu Dec 12 15:40:07 MET 1996