Next: 10.2.3 signal under Linux Up: 10.2 Signal handling Previous: 10.2.1 Signals under SVR4

## 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.