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diff --git a/man3/sigvec.3 b/man3/sigvec.3 new file mode 100644 index 0000000..c4529a8 --- /dev/null +++ b/man3/sigvec.3 @@ -0,0 +1,283 @@ +'\" t +.\" Copyright (c) 2005 by Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH sigvec 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +sigvec, sigblock, sigsetmask, siggetmask, sigmask \- BSD signal API +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <signal.h> +.PP +.BI "[[deprecated]] int sigvec(int " sig ", const struct sigvec *" vec , +.BI " struct sigvec *" ovec ); +.PP +.BI "[[deprecated]] int sigmask(int " signum ); +.PP +.BI "[[deprecated]] int sigblock(int " mask ); +.BI "[[deprecated]] int sigsetmask(int " mask ); +.B [[deprecated]] int siggetmask(void); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +All functions shown above: +.nf + Since glibc 2.19: + _DEFAULT_SOURCE + glibc 2.19 and earlier: + _BSD_SOURCE +.fi +.SH DESCRIPTION +These functions are provided in glibc as a compatibility interface +for programs that make use of the historical BSD signal API. +This API is obsolete: new applications should use the POSIX signal API +.RB ( sigaction (2), +.BR sigprocmask (2), +etc.). +.PP +The +.BR sigvec () +function sets and/or gets the disposition of the signal +.I sig +(like the POSIX +.BR sigaction (2)). +If +.I vec +is not NULL, it points to a +.I sigvec +structure that defines the new disposition for +.IR sig . +If +.I ovec +is not NULL, it points to a +.I sigvec +structure that is used to return the previous disposition of +.IR sig . +To obtain the current disposition of +.I sig +without changing it, specify NULL for +.IR vec , +and a non-null pointer for +.IR ovec . +.PP +The dispositions for +.B SIGKILL +and +.B SIGSTOP +cannot be changed. +.PP +The +.I sigvec +structure has the following form: +.PP +.in +4n +.EX +struct sigvec { + void (*sv_handler)(int); /* Signal disposition */ + int sv_mask; /* Signals to be blocked in handler */ + int sv_flags; /* Flags */ +}; +.EE +.in +.PP +The +.I sv_handler +field specifies the disposition of the signal, and is either: +the address of a signal handler function; +.BR SIG_DFL , +meaning the default disposition applies for the signal; or +.BR SIG_IGN , +meaning that the signal is ignored. +.PP +If +.I sv_handler +specifies the address of a signal handler, then +.I sv_mask +specifies a mask of signals that are to be blocked while +the handler is executing. +In addition, the signal for which the handler is invoked is +also blocked. +Attempts to block +.B SIGKILL +or +.B SIGSTOP +are silently ignored. +.PP +If +.I sv_handler +specifies the address of a signal handler, then the +.I sv_flags +field specifies flags controlling what happens when the handler is called. +This field may contain zero or more of the following flags: +.TP +.B SV_INTERRUPT +If the signal handler interrupts a blocking system call, +then upon return from the handler the system call is not restarted: +instead it fails with the error +.BR EINTR . +If this flag is not specified, then system calls are restarted +by default. +.TP +.B SV_RESETHAND +Reset the disposition of the signal to the default +before calling the signal handler. +If this flag is not specified, then the handler remains established +until explicitly removed by a later call to +.BR sigvec () +or until the process performs an +.BR execve (2). +.TP +.B SV_ONSTACK +Handle the signal on the alternate signal stack +(historically established under BSD using the obsolete +.BR sigstack () +function; the POSIX replacement is +.BR sigaltstack (2)). +.PP +The +.BR sigmask () +macro constructs and returns a "signal mask" for +.IR signum . +For example, we can initialize the +.I vec.sv_mask +field given to +.BR sigvec () +using code such as the following: +.PP +.in +4n +.EX +vec.sv_mask = sigmask(SIGQUIT) | sigmask(SIGABRT); + /* Block SIGQUIT and SIGABRT during + handler execution */ +.EE +.in +.PP +The +.BR sigblock () +function adds the signals in +.I mask +to the process's signal mask +(like POSIX +.IR sigprocmask(SIG_BLOCK) ), +and returns the process's previous signal mask. +Attempts to block +.B SIGKILL +or +.B SIGSTOP +are silently ignored. +.PP +The +.BR sigsetmask () +function sets the process's signal mask to the value given in +.I mask +(like POSIX +.IR sigprocmask(SIG_SETMASK) ), +and returns the process's previous signal mask. +.PP +The +.BR siggetmask () +function returns the process's current signal mask. +This call is equivalent to +.IR sigblock(0) . +.SH RETURN VALUE +The +.BR sigvec () +function returns 0 on success; on error, it returns \-1 and sets +.I errno +to indicate the error. +.PP +The +.BR sigblock () +and +.BR sigsetmask () +functions return the previous signal mask. +.PP +The +.BR sigmask () +macro returns the signal mask for +.IR signum . +.SH ERRORS +See the ERRORS under +.BR sigaction (2) +and +.BR sigprocmask (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 sigvec (), +.BR sigmask (), +.BR sigblock (), +.BR sigsetmask (), +.BR siggetmask () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +None. +.SH HISTORY +.TP +.BR sigvec () +.TQ +.BR sigblock () +.TQ +.BR sigmask () +.TQ +.BR sigsetmask () +4.3BSD. +.TP +.BR siggetmask () +Unclear origin. +.TP +.BR sigvec () +Removed in glibc 2.21. +.SH NOTES +On 4.3BSD, the +.BR signal () +function provided reliable semantics (as when calling +.BR sigvec () +with +.I vec.sv_mask +equal to 0). +On System V, +.BR signal () +provides unreliable semantics. +POSIX.1 leaves these aspects of +.BR signal () +unspecified. +See +.BR signal (2) +for further details. +.PP +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 SEE ALSO +.BR kill (2), +.BR pause (2), +.BR sigaction (2), +.BR signal (2), +.BR sigprocmask (2), +.BR raise (3), +.BR sigpause (3), +.BR sigset (3), +.BR signal (7) |