28 lines
649 B
C
28 lines
649 B
C
#include <signal.h>
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void (*sigset(int sig, void (*handler)(int)))(int)
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{
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struct sigaction sa, sa_old;
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sigset_t mask, mask_old;
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sigemptyset(&mask);
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if (sigaddset(&mask, sig) < 0)
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return SIG_ERR;
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if (handler == SIG_HOLD) {
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if (sigaction(sig, 0, &sa_old) < 0)
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return SIG_ERR;
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if (sigprocmask(SIG_BLOCK, &mask, &mask_old) < 0)
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return SIG_ERR;
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} else {
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sa.sa_handler = handler;
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sa.sa_flags = 0;
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sigemptyset(&sa.sa_mask);
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if (sigaction(sig, &sa, &sa_old) < 0)
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return SIG_ERR;
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if (sigprocmask(SIG_UNBLOCK, &mask, &mask_old) < 0)
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return SIG_ERR;
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}
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return sigismember(&mask_old, sig) ? SIG_HOLD : sa_old.sa_handler;
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}
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