In your third step you said "Blocking every signal in the set, i.e. adding SIGILL to the set of blocked signals".
Didn't we add SIGILL in previous step?
You added it to the s variable, is all. The system hasn't been told to use it, that's what sigprocmask is for.
Quote:
If the set is empty then we only blocking SIGILL?
No. From man sigprocmask:
...meaning. you're adding SIGILL to whatever signals are currently being blocked.
Quote:
When we have empty set of signals does that mean there isn't any signals in it?
(posted this in the scripting forum as well, but figured it should go here) So, what's going on is this:
For our program, we had to create our own shell, and if the user pressed ctrl-c just at the cmdline, then this signal would be ignored, but if there is a foreground process running, let's... (0 Replies)
How can use signals in a C program If i want a child program to signal it's parent program that it(child) program has completed the task that it was assigned.:confused: (2 Replies)
can any one give me an example of a concurrency program in threads and signals, i.e how to deliver messages between threads using signals. thanks (0 Replies)
can any one give me an example of a concurrency program in threads and signals, i.e how to deliver messages between threads using signals. thanks (2 Replies)
Hi,
In our program, we are using SIGTERM and i tired to put break point in this function. But my debuger is unable to brake at that point.
I am working on Mac X and using XCode.
Thanks (0 Replies)
I have following problem with this code..
First time trough the main loop.....
perror gives ....blocked signal:success(all other times gives illlegal seek)
Should every time trought the main loop be success??
And the perror otside of main loop...didn't change mask:success
That line of code... (2 Replies)
I know how to add signal to a set. But what if I want to add 2 or 3 signals to the set.
I know I can use sigaddset (&set,SIGBUS)....but what if I want to add SIGBUS and SIGALRM at once. Do i have to do it like this..
sigaddset (&set,SIGBUS);
sigaddset (&set,SIGALRM);
Is there another way to... (0 Replies)
how can do this programs in c++
Program description:
Infinite loop in a program starts working with 2 seconds the screen (console) "I 'm trying" to write, but it automatically after 10 seconds, the screen "Close" will terminate the execution of typing.
c++ code (3 Replies)
Hi All,
The problem statement is as below:
Problem: A process (exe) is getting executed in background. The output of this process is getting logged in a file. After successfully running for some time the process gets terminated. In the log file following is present:
^M[7m Interrupt ^M[27m... (8 Replies)
Discussion started by: Praty.27
8 Replies
LEARN ABOUT NETBSD
sigblock
SIGBLOCK(3) BSD Library Functions Manual SIGBLOCK(3)NAME
sigblock -- block signals
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <signal.h>
int
sigblock(int mask);
int
sigmask(signum);
DESCRIPTION
This interface is made obsolete by: sigprocmask(2).
sigblock() adds the signals specified in mask to the set of signals currently being blocked from delivery. Signals are blocked if the corre-
sponding bit in mask is a 1; the macro sigmask() is provided to construct the mask for a given signum.
It is not possible to block SIGKILL or SIGSTOP; this restriction is silently imposed by the system.
RETURN VALUES
The previous set of masked signals is returned.
EXAMPLES
The following example using sigblock():
int omask;
omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
Becomes:
sigset_t set, oset;
sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGHUP);
sigprocmask(SIG_BLOCK, &set, &oset);
Another use of sigblock() is to get the current set of masked signals without changing what is actually blocked. Instead of:
int set;
set = sigblock(0);
Use the following:
sigset_t set;
sigprocmask(SIG_BLOCK, NULL, &set);
SEE ALSO kill(2), sigaction(2), sigprocmask(2), sigsetmask(3), sigsetops(3)HISTORY
The sigblock() function call appeared in 4.2BSD and has been deprecated.
BSD August 10, 2002 BSD