| 1 | |
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| 2 | /* |
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| 3 | * signals.c -- general signals interface for nmh |
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| 4 | * |
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| 5 | * $Id: signals.c,v 1.1.1.1 1999-02-07 18:14:10 danw Exp $ |
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| 6 | */ |
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| 7 | |
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| 8 | #include <h/mh.h> |
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| 9 | #include <h/signals.h> |
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| 10 | |
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| 11 | |
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| 12 | int |
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| 13 | SIGPROCMASK (int how, const sigset_t *set, sigset_t *oset) |
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| 14 | { |
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| 15 | #ifdef POSIX_SIGNALS |
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| 16 | return sigprocmask(how, set, oset); |
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| 17 | #else |
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| 18 | # ifdef BSD_SIGNALS |
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| 19 | switch(how) { |
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| 20 | case SIG_BLOCK: |
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| 21 | *oset = sigblock(*set); |
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| 22 | break; |
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| 23 | case SIG_UNBLOCK: |
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| 24 | sigfillset(*oset); |
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| 25 | *oset = sigsetmask(*oset); |
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| 26 | sigsetmask(*oset & ~(*set)); |
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| 27 | break; |
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| 28 | case SIG_SETMASK: |
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| 29 | *oset = sigsetmask(*set); |
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| 30 | break; |
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| 31 | default: |
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| 32 | adios(NULL, "unknown flag in SIGPROCMASK"); |
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| 33 | break; |
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| 34 | } |
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| 35 | return 0; |
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| 36 | # endif |
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| 37 | #endif |
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| 38 | } |
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| 39 | |
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| 40 | |
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| 41 | /* |
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| 42 | * A version of the function `signal' that uses reliable |
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| 43 | * signals, if the machine supports them. Also, (assuming |
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| 44 | * OS support), it restarts interrupted system calls for all |
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| 45 | * signals except SIGALRM. |
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| 46 | */ |
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| 47 | |
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| 48 | SIGNAL_HANDLER |
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| 49 | SIGNAL (int sig, SIGNAL_HANDLER func) |
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| 50 | { |
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| 51 | #ifdef POSIX_SIGNALS |
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| 52 | struct sigaction act, oact; |
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| 53 | |
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| 54 | act.sa_handler = func; |
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| 55 | sigemptyset(&act.sa_mask); |
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| 56 | act.sa_flags = 0; |
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| 57 | |
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| 58 | if (sig == SIGALRM) { |
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| 59 | # ifdef SA_INTERRUPT |
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| 60 | act.sa_flags |= SA_INTERRUPT; /* SunOS */ |
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| 61 | # endif |
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| 62 | } else { |
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| 63 | # ifdef SA_RESTART |
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| 64 | act.sa_flags |= SA_RESTART; /* SVR4, BSD4.4 */ |
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| 65 | # endif |
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| 66 | } |
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| 67 | if (sigaction(sig, &act, &oact) < 0) |
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| 68 | return (SIG_ERR); |
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| 69 | return (oact.sa_handler); |
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| 70 | #else |
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| 71 | return signal (sig, func); |
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| 72 | #endif |
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| 73 | } |
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| 74 | |
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| 75 | |
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| 76 | /* |
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| 77 | * A version of the function `signal' that will set |
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| 78 | * the handler of `sig' to `func' if the signal is |
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| 79 | * not currently set to SIG_IGN. Also uses reliable |
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| 80 | * signals if available. |
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| 81 | */ |
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| 82 | SIGNAL_HANDLER |
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| 83 | SIGNAL2 (int sig, SIGNAL_HANDLER func) |
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| 84 | { |
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| 85 | #ifdef POSIX_SIGNALS |
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| 86 | struct sigaction act, oact; |
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| 87 | |
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| 88 | if (sigaction(sig, NULL, &oact) < 0) |
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| 89 | return (SIG_ERR); |
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| 90 | if (oact.sa_handler != SIG_IGN) { |
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| 91 | act.sa_handler = func; |
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| 92 | sigemptyset(&act.sa_mask); |
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| 93 | act.sa_flags = 0; |
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| 94 | |
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| 95 | if (sig == SIGALRM) { |
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| 96 | # ifdef SA_INTERRUPT |
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| 97 | act.sa_flags |= SA_INTERRUPT; /* SunOS */ |
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| 98 | # endif |
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| 99 | } else { |
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| 100 | # ifdef SA_RESTART |
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| 101 | act.sa_flags |= SA_RESTART; /* SVR4, BSD4.4 */ |
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| 102 | # endif |
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| 103 | } |
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| 104 | if (sigaction(sig, &act, &oact) < 0) |
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| 105 | return (SIG_ERR); |
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| 106 | } |
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| 107 | return (oact.sa_handler); |
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| 108 | #else |
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| 109 | SIGNAL_HANDLER ofunc; |
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| 110 | |
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| 111 | if ((ofunc = signal (sig, SIG_IGN)) != SIG_IGN) |
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| 112 | signal (sig, func); |
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| 113 | return ofunc; |
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| 114 | #endif |
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| 115 | } |
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| 116 | |
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