SIGPROCMASK
Section: System Calls (2)
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BSD mandoc
NAME
sigprocmask
- manipulate current signal mask
SYNOPSIS
Fd #include <signal.h>
Ft int
Fn sigprocmask int how const sigset_t *set sigset_t *oset
DESCRIPTION
The
Fn sigprocmask
function examines and/or changes the current signal mask (those signals
that are blocked from delivery).
Signals are blocked if they are members of the current signal mask set.
If
Fa set
is not null, the action of
Fn sigprocmask
depends on the value of the parameter
Fa how .
The signal mask is changed as a function of the specified
Fa set
and the current mask.
The function is specified by
Fa how
using one of the following values from
Aq Pa signal.h :
- SIG_BLOCK
-
The new mask is the union of the current mask and the specified
Fa set .
- SIG_UNBLOCK
-
The new mask is the intersection of the current mask
and the complement of the specified
Fa set .
- SIG_SETMASK
-
The current mask is replaced by the specified
Fa set .
If
Fa oset
is not null, it is set to
the previous value of the signal mask.
When
Fa set
is null,
the value of
how
is insignificant and the mask remains unset
providing a way to examine the signal mask without modification.
The system
quietly disallows
SIGKILL
or
SIGSTOP
to be blocked.
RETURN VALUES
A 0 value indicated that the call succeeded. A -1 return value
indicates an error occurred and
errno
is set to indicated the reason.
ERRORS
The
Fn sigprocmask
call will fail and the signal mask will be unchanged if one
of the following occurs:
- Bq Er EINVAL
-
Fa how
has a value other than those listed here.
SEE ALSO
kill(2),
sigaction(2),
sigsetops(3),
sigsuspend(2)
STANDARDS
The
Fn sigprocmask
function call is expected to
conform to
St -p1003.1-88 .
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUES
-
- ERRORS
-
- SEE ALSO
-
- STANDARDS
-
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Time: 16:28:59 GMT, April 18, 2022