10.2.2 Linux signal options

The following values for the sa_flags member of the sigaction structure are defined for Linux.

• SA_NOCLDSTOP: Don't send SIGCHLD when a child process is stopped.
• SA_RESTART: Force restart of certain system calls when interrupted by a signal handler.
• SA_NOMASK: Disable signal mask (which blocks signals during execution of a signal handler).
• SA_ONESHOT: Clear signal handler after execution. Note that SVR4 uses SA_RESETHAND to mean the same thing.
• SA_INTERRUPT: Defined under Linux, but unused. Under SunOS, system calls were automatically restarted, and this flag disabled that behavior.
• SA_STACK: Currently a no-op, to be used for signal stacks.

Note that POSIX.1 defines only SA_NOCLDSTOP, and there are several other options defined by SVR4 not available under Linux. When porting applications which use sigaction, you may have to modify the values of sa_flags to get the appropriate behavior.