siginterrupt(3)siginterrupt(3)NAMEsiginterrupt - Allow signals to interrupt functions
SYNOPSIS
#include <signal.h>
int siginterrupt(
int sig,
int flag );
LIBRARY
Standard C Library (libc)
Berkeley Compatibility Library (libbsd.a)
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
siginterrupt() (libc version): XSH4.2
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
PARAMETERS
Specifies the expected interrupt signal. Indicates whether the func‐
tion is to restart when interrupted by the specified signal. When the
flag parameter is TRUE, restart is disabled. When the flag parameter is
FALSE, restart is enabled.
DESCRIPTION
The siginterrupt() function is used to change the restart behavior of a
system call when it is interrupted by the signal specified by the sig
parameter. When the flag parameter is FALSE (0), system calls restart
when they are interrupted by the sig signal and no data has yet been
transferred.
When the flag parameter is TRUE (1), restart of system calls is dis‐
abled. When a system call is interrupted by the sig signal and no data
has been transferred, the function returns a value of -1 with errno set
to [EINTR]. Otherwise, interrupted system calls that have started
transferring data return a value that is the number of data bytes actu‐
ally transferred.
[Tru64 UNIX] System call interrupt is the default behavior unless the
calling program has been linked with the libbsd library and the libbsd
version of signal() has been used.
NOTES
The siginterrupt() function is provided for compatibility with BSD sys‐
tems. When writing or rewriting portable applications, use the sigac‐
tion() function with the SA_RESTART option instead of siginterrupt().
The use of the siginterrupt() function does not affect signal-handling
semantics in any other way. Programs may switch between restartable and
interruptible system call operation as often as desired in the execu‐
tion of a program.
Issuing a siginterrupt() call during the execution of a signal handler
causes the new action to take place when the next instance of the spec‐
ified signal is caught.
RETURN VALUES
Upon successful completion, siginterrupt() returns a value of 0 (zero).
Otherwise, a value of -1 is returned to indicate that an invalid signal
value has been used.
ERRORS
If the siginterrupt() function fails, errno may be set to the following
value: The value of the sig parameter does not represent a valid sig‐
nal.
SEE ALSO
Functions: sigaction(2), sigprocmask(2), sigsuspend(2)
Standards: standards(5)siginterrupt(3)
