bsd_signal


SYNOPSIS
       #define _XOPEN_SOURCE       /* See feature_test_macros(7) */
       #include <signal.h>

       typedef void (*sighandler_t)(int);

       sighandler_t bsd_signal(int signum, sighandler_t handler);

DESCRIPTION
       The  bsd_signal()  function  takes the same arguments, and performs the
       same task, as signal(2).

       The difference between the two is that bsd_signal()  is  guaranteed  to
       provide  reliable  signal semantics, that is: a) the disposition of the
       signal is not reset to the default when  the  handler  is  invoked;  b)
       delivery of further instances of the signal is blocked while the signal
       handler is executing; and c) if the handler interrupts a blocking  sys-
       tem  call, then the system call is automatically restarted.  A portable
       application cannot rely on signal(2) to provide these guarantees.

RETURN VALUE
       The bsd_signal() function returns the previous value of the signal han-
       dler, or SIG_ERR on error.

ERRORS
       As for signal(2).

CONFORMING TO
       4.2BSD,   POSIX.1-2001.   POSIX.1-2008  removes  the  specification  of
       bsd_signal(), recommending the use of sigaction(2) instead.

NOTES
       Use of bsd_signal() should be avoided; use sigaction(2) instead.

       On modern Linux systems, bsd_signal()  and  signal(2)  are  equivalent.
       But  on  older systems, signal(2) provided unreliable signal semantics;
       see signal(2) for details.

       The use of sighandler_t is a GNU extension; this type is  only  defined
       if the _GNU_SOURCE feature test macro is defined.

SEE ALSO
       sigaction(2), signal(2), sysv_signal(3), signal(7)

COLOPHON
       This  page  is  part of release 3.35 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://man7.org/linux/man-pages/.



                                  2009-03-15                     BSD_SIGNAL(3)
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