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diff --git a/man/man3/sigset.3 b/man/man3/sigset.3 new file mode 100644 index 0000000..195b5fe --- /dev/null +++ b/man/man3/sigset.3 @@ -0,0 +1,265 @@ +'\" t +.\" Copyright (c) 2005 by Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH sigset 3 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +sigset, sighold, sigrelse, sigignore \- System V signal API +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <signal.h> +.P +.B typedef void (*sighandler_t)(int); +.P +.BI "[[deprecated]] sighandler_t sigset(int " sig ", sighandler_t " disp ); +.P +.BI "[[deprecated]] int sighold(int " sig ); +.BI "[[deprecated]] int sigrelse(int " sig ); +.BI "[[deprecated]] int sigignore(int " sig ); +.fi +.P +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.P +.BR sigset (), +.BR sighold (), +.BR sigrelse (), +.BR sigignore (): +.nf + _XOPEN_SOURCE >= 500 +.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED +.fi +.SH DESCRIPTION +These functions are provided in glibc as a compatibility interface +for programs that make use of the historical System V signal API. +This API is obsolete: new applications should use the POSIX signal API +.RB ( sigaction (2), +.BR sigprocmask (2), +etc.) +.P +The +.BR sigset () +function modifies the disposition of the signal +.IR sig . +The +.I disp +argument can be the address of a signal handler function, +or one of the following constants: +.TP +.B SIG_DFL +Reset the disposition of +.I sig +to the default. +.TP +.B SIG_IGN +Ignore +.IR sig . +.TP +.B SIG_HOLD +Add +.I sig +to the process's signal mask, but leave the disposition of +.I sig +unchanged. +.P +If +.I disp +specifies the address of a signal handler, then +.I sig +is added to the process's signal mask during execution of the handler. +.P +If +.I disp +was specified as a value other than +.BR SIG_HOLD , +then +.I sig +is removed from the process's signal mask. +.P +The dispositions for +.B SIGKILL +and +.B SIGSTOP +cannot be changed. +.P +The +.BR sighold () +function adds +.I sig +to the calling process's signal mask. +.P +The +.BR sigrelse () +function removes +.I sig +from the calling process's signal mask. +.P +The +.BR sigignore () +function sets the disposition of +.I sig +to +.BR SIG_IGN . +.SH RETURN VALUE +On success, +.BR sigset () +returns +.B SIG_HOLD +if +.I sig +was blocked before the call, +or the signal's previous disposition +if it was not blocked before the call. +On error, +.BR sigset () +returns \-1, with +.I errno +set to indicate the error. +(But see BUGS below.) +.P +The +.BR sighold (), +.BR sigrelse (), +and +.BR sigignore () +functions return 0 on success; on error, these functions return \-1 and set +.I errno +to indicate the error. +.SH ERRORS +For +.BR sigset () +see the ERRORS under +.BR sigaction (2) +and +.BR sigprocmask (2). +.P +For +.BR sighold () +and +.BR sigrelse () +see the ERRORS under +.BR sigprocmask (2). +.P +For +.BR sigignore (), +see the errors under +.BR sigaction (2). +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR sigset (), +.BR sighold (), +.BR sigrelse (), +.BR sigignore () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +POSIX.1-2008. +.TP +.I sighandler_t +GNU. +POSIX.1 uses the same type but without a +.IR typedef . +.SH HISTORY +glibc 2.1. +SVr4, POSIX.1-2001. +POSIX.1-2008 marks these functions +as obsolete, recommending the use of +.BR sigaction (2), +.BR sigprocmask (2), +.BR pthread_sigmask (3), +and +.BR sigsuspend (2) +instead. +.SH NOTES +The +.BR sigset () +function provides reliable signal handling semantics (as when calling +.BR sigaction (2) +with +.I sa_mask +equal to 0). +.P +On System V, the +.BR signal () +function provides unreliable semantics (as when calling +.BR sigaction (2) +with +.I sa_mask +equal to +.IR "SA_RESETHAND | SA_NODEFER" ). +On BSD, +.BR signal () +provides reliable semantics. +POSIX.1-2001 leaves these aspects of +.BR signal () +unspecified. +See +.BR signal (2) +for further details. +.P +In order to wait for a signal, +BSD and System V both provided a function named +.BR sigpause (3), +but this function has a different argument on the two systems. +See +.BR sigpause (3) +for details. +.SH BUGS +Before glibc 2.2, +.BR sigset () +did not unblock +.I sig +if +.I disp +was specified as a value other than +.BR SIG_HOLD . +.P +Before glibc 2.5, +.BR sigset () +does not correctly return the previous disposition of the signal +in two cases. +First, if +.I disp +is specified as +.BR SIG_HOLD , +then a successful +.BR sigset () +always returns +.BR SIG_HOLD . +Instead, it should return the previous disposition of the signal +(unless the signal was blocked, in which case +.B SIG_HOLD +should be returned). +Second, if the signal is currently blocked, then +the return value of a successful +.BR sigset () +should be +.BR SIG_HOLD . +Instead, the previous disposition of the signal is returned. +These problems have been fixed since glibc 2.5. +.\" See http://sourceware.org/bugzilla/show_bug.cgi?id=1951 +.SH SEE ALSO +.BR kill (2), +.BR pause (2), +.BR sigaction (2), +.BR signal (2), +.BR sigprocmask (2), +.BR raise (3), +.BR sigpause (3), +.BR sigvec (3), +.BR signal (7) |