Does the handler auto-restart syscalls?

Challenge

sigaction's sa_flags word controls handler behaviour; the SA_RESTART bit makes interrupted slow syscalls resume instead of failing with EINTR. Test for it.

Task

Implement int restarts_syscalls(int flags) that returns 1 if the SA_RESTART bit is set in flags, else 0.

Input

• flags: an sa_flags value (bitmask).

Output

1 if SA_RESTART is set, else 0.

Example

restarts_syscalls(SA_RESTART)   ->   1
restarts_syscalls(0)            ->   0

Input format

flags: an sa_flags bitmask.

Output format

1 if the SA_RESTART bit is set, else 0.

Constraints

flags is an int representing sa_flags in a struct sigaction.

Starter code

#include <signal.h>

int restarts_syscalls(int flags) {
    /* TODO */
    return 0;
}

Common mistakes

Using equality (flags == SA_RESTART) instead of bitwise AND (& SA_RESTART).

Edge cases to handle

flags == 0, flags with SA_RESTART set among other bits, flags without SA_RESTART.