36 lines
871 B
C
36 lines
871 B
C
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/* SYSVR4 and ANSI compatible signal(2). */
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#include <lib.h>
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#define sigaction _sigaction
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#define sigemptyset _sigemptyset
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#include <signal.h>
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PUBLIC sighandler_t signal(sig, disp)
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int sig; /* signal number */
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sighandler_t disp; /* signal handler, or SIG_DFL, or SIG_IGN */
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{
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struct sigaction sa, osa;
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if (sig <= 0 || sig > _NSIG || sig == SIGKILL) {
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errno = EINVAL;
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return(SIG_ERR);
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}
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sigemptyset(&sa.sa_mask);
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#ifdef WANT_UNRELIABLE_SIGNALS
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/* Allow the signal being handled to interrupt the signal handler. */
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sa.sa_flags = SA_NODEFER;
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/* When signal is caught, reset signal handler to SIG_DFL for all but
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* SIGILL and SIGTRAP.
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*/
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if (sig != SIGILL && sig != SIGTRAP) sa.sa_flags |= SA_RESETHAND;
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#else
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sa.sa_flags = 0;
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#endif
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sa.sa_handler = disp;
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if (sigaction(sig, &sa, &osa) < 0) return(SIG_ERR);
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return(osa.sa_handler);
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}
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