12-04-2002
Thanks LivinFree...That did the trick.
10 More Discussions You Might Find Interesting
1. Programming
Hi,
I have an c++ application which uses the function fork and execvp().
The parent does not wait until the child ends. The parents just creates children and let them do their stuff.
You can see the parent program as a batch-manager.
I have added a SIGCHLD handler to the program:
void... (3 Replies)
Discussion started by: jens
3 Replies
2. Programming
Hey guys,
I am trying to write a little shell, and was writing a signal handler to handle SIGINT (I am using 'stty intr ^C' and using ctrl-C to give SIGINT).
I wrote this signal handler: void handle_sigint()
{
write(2,"handling sigint\n",16);
write(1,"\nshell% ",8);
}
... (4 Replies)
Discussion started by: blowtorch
4 Replies
3. Programming
I have written a program to demonstrate a problem I have encountered when using BSD style asynchronous input using the O_ASYNC flag in conjunction with a real time interval timer sending regular SIGALRM signals to the program. The SIGIO handler obeys all safe practices, using only an atomic update... (8 Replies)
Discussion started by: stewartw
8 Replies
4. Programming
Is it ok to use exit() inside a signal handler?
I catch SIGUSR1 in a signal handler and I try to close a file and then exit. The result is inconsistent. Sometimes the process exit and sometimes it returns to the original state before the signal handler was invoked.
Perhaps exit is not legal in... (8 Replies)
Discussion started by: Tuvia
8 Replies
5. Programming
Hi,
I have a daq program that runs in an infinite loop until it receives SIGINT. A handler catches the signal and sets a flag to stop the while loop. After the loop some things have to be cleaned up.
The problem is that I want my main while loop to wait until the next full second begins, to... (2 Replies)
Discussion started by: soeckel
2 Replies
6. Shell Programming and Scripting
I have a problem with signal handlers not working.
I have a long 1000 line code and somehow this code for signal handling is not working:
$SIG{INT} = \&interrupt;
sub interrupt {
print STDERR "Caught a control c!\n";
exit; # or just about anything else you'd want to do
}
Any... (2 Replies)
Discussion started by: som.nitk
2 Replies
7. Programming
Hi,
I have a problem with signal handler algorithm in linux. My code is hanging ( It is continuously looping inside the signal handler) . I am pasting my code here...
Please provide me some help regarding this. I googled many places and wrote this code.. but doesnt seem to be working without... (6 Replies)
Discussion started by: sree_ec
6 Replies
8. Shell Programming and Scripting
I was working on some Perl code that does signal handling and I came across this one liner and wasn't sure what it was doing.
local $SIG{__DIE__} = sub {$! = 2; die $_;};
I think the first part of the anonymous subroutine is setting $! to 2, but I am not sure what the second part is doing. ... (1 Reply)
Discussion started by: SFNYC
1 Replies
9. Programming
i m unble to execute code of
signal handler using
a) Wait b) Waitpid (1 Reply)
Discussion started by: madhura
1 Replies
10. Programming
Hello,
I'm writing some serial(UART) handler but have stuck on few issues, maybe anyone can help to show me what I'm doing wrong.
Basically I'm intending to write serial RX signal handler.
Application receives defined packages of data over serial which contains header and payload. Handler... (3 Replies)
Discussion started by: Lauris_k
3 Replies
LEARN ABOUT CENTOS
trace_printk
TRACE_PRINTK(9) Driver Basics TRACE_PRINTK(9)
NAME
trace_printk - printf formatting in the ftrace buffer
SYNOPSIS
trace_printk(fmt, ...);
ARGUMENTS
fmt
the printf format for printing
...
variable arguments
NOTE
__trace_printk is an internal function for trace_printk and the ip is passed in via the trace_printk macro.
This function allows a kernel developer to debug fast path sections that printk is not appropriate for. By scattering in various printk
like tracing in the code, a developer can quickly see where problems are occurring.
This is intended as a debugging tool for the developer only. Please refrain from leaving trace_printks scattered around in your code.
(Extra memory is used for special buffers that are allocated when trace_printk is used)
A little optization trick is done here. If there's only one argument, there's no need to scan the string for printf formats. The trace_puts
will suffice. But how can we take advantage of using trace_puts when trace_printk has only one argument? By stringifying the args and
checking the size we can tell whether or not there are args. __stringify((__VA_ARGS__)) will turn into "() " with a size of 3 when there
are no args, anything else will be bigger. All we need to do is define a string to this, and then take its size and compare to 3. If it's
bigger, use do_trace_printk otherwise, optimize it to trace_puts. Then just let gcc optimize the rest.
COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 TRACE_PRINTK(9)