BSD_SIGNAL(3) Linux Programmer's Manual BSD_SIGNAL(3) NAME bsd_signal - signal handling with BSD semantics 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). ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). +-------------+---------------+---------+ |Interface | Attribute | Value | +-------------+---------------+---------+ |bsd_signal() | Thread safety | MT-Safe | +-------------+---------------+---------+ 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 defined only 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 4.10 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. 2015-03-02 BSD_SIGNAL(3) |