I have a signal handler in my tool, which is registered and used between some particular interval (i am using timer). Now this signal handler should NOT allow any other handler to be registered or invoked after this handler is once registered. Is there any way to accomplish this?
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I'm doing a project in Unix version Ubuntu 10.04. I'm doing an standalone app using C++(Qcreator) and GMT(generic mapping tool) so i need help in the following: how to invoke any extension files using C++?
View 1 Replies View RelatedI have a few questions regarding HTML, UNIX and Javascript. I've been tasked with creating a fairly simple webpage that takes a few inputs. Each input must correspond to an argument in a UNIX command running on a server.On a UNIX server we have a script (.ksh) that takes 3 arguments. The result of the script is a data file which is FTP'ed to an external server. Let's forget about the FTP portion for now. I would like to know where I should begin.What I know so far:
1) I will need HTML to create the webpage. Skill level is high
2) I will need Javascript to make my webpage more interactive. Skill level is high.
3) I will need to understand the UNIX environment. Skill level is high.
I have the following requirement in my module. The driver gets some data from the external device. After getting 1MB of data it has to send it to the user space application. What is the best thing to implement for this in driver.? Is it ok to implement like, after getting data, the driver will send a signal to the user space application. Then the user space application sends an ioctl to read the data. Is there any alternate, that the driver directly sends the data without the user space application asks for it.?
View 4 Replies View RelatedI've been looking for help on the #debian irc chan, this was my problem :when I startx, my two screens stop receiving any signal.I was using the vesa driver, so the guy told me to use radeonhd driver instead (I have a radeonhd graphic card)when using radeonhd driver, it tells me that no screen or monitor is found then he told me that I should install fglrx and that he couldn't help me for this
View 14 Replies View RelatedDoes anyone know how to stop ubuntu (when loading) looking for wifi signal's in the 5000000 khz range? I have a problem with other devices around my house that operate on this range of frequencies and it effects ubuntu while its booting, to the extent that it won�t load. My wireless router is on the 2000000 khz range therefore I only really need Ubuntu to look for devices on this range of frequencies. If anyone know a way to prevent Ubuntu looking on the 5000000 khz range by editing something I would be very greatful to know how to do this.
As at the moment I am having to boot about 5 times until it eventually decided to load. Sometimes the only way I can get in, is by going into recovery mode, dropping to terminal and typing in: "sudo gdm" and eventually I get it. Which is a right pain. Please see my previous post outlining my problem: [URL]
I am trying to give access to ONE single user to start and shutdown tomcat server. The problem being, when I enter syntax: username ALL= /etc/init.d/tomcat5, /usr/local/tomcat/webapps, PASSWD:ALL This gives the user access to start and stop tomcat but also gives user access to start and stop other services within /etc/init.d - such as httpd etc... What is the proper way to give user access to start and stop service, and limiting that power to only one service....
View 2 Replies View RelatedI want that I click with the mouse on the video, it paused.I notice that there is "BaconVideoWidget" which I guess is the video rendering widget but it don't have signal named "clicked":
Code:
vd = totem_object.get_video_widget()
vd.connect("clicked", vd.hide)
[code]....
I'm doing the shell history audit logging using syslog to gather the command history. I'm using this well publicized method using trap and logger:
declare -r REAL_LOGNAME=`/usr/bin/who am i | cut -d" " -f1`
function log2syslog {
declare command
command=`fc -ln -0`
logger -p local1.notice -t bash -i ": $REAL_LOGNAME as $LOGNAME :$command"
}
trap log2syslog DEBUG TERM
The problem is that the trap on DEBUG will catch the next to last command executed (by virtue of the "fc" command) which is not the current command executed. TERM will catch that "next to last" command on exit, thus completing the logging of each command executed during that session.
However, CTL+D doesn't seem to emit a SIGTERM signal. What signal is actually being emitted and can it be trapped? I guess another question would be whether there is a way to trap history after command line execution? Moving to Bash 4.1 isn't possible in our "supported" multi-platform environment
I have created a pthread, and installed a signal handler inside that, same way as we do in main( ) function. The thread's signal handler is a separate function. Surprisingly, it is not working, that is the thread's signal handler is not able to catch signals. Here is the code:
Code: #include <unistd.h>
#include <sys/types.h>
#include <stdio.h>
#include <signal.h>
typedef struct data
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I have a Socket library, written in C++, in which the method used to send data never has the opportunity to handle an errno of SIGPIPE. Thus I thought perhaps I should setup a signal handler to receive the signal, but this too is not being called.Is there something that I am missing or doing that is completely wrong? Below is the relevant code. Note that a SIGPIPE signal is generated when the Server is unable to send data to the Client (e.g. the client has terminated).Server code:
Code:
#include <TCPServerSocket.hpp>
#include <string>
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Is it possible to connect a signal handler to a variable?So when the variable changes the signal handler is called.I have a vector containing strings which i want to parse when there are one or more available strings in the vector
View 3 Replies View RelatedI am writing a bash script where I need standard Input should be saved in a file and should be terminated by passing CTRL+D signal. Any clue how can I do that in bash script.
e.g.
Enter one line at a time
Press CTRL+D to finish
But unable to catch the SIGTERM signal if I do shutdown, as man pages says shutdown genrates the SIGTERM and SIGKILL signals, but we cant handle the SIGKILL signal. My code is working fine if I genrate the SIGTERM signal by Kill command, and also for SIGINT signgal genrated from the CTRL+c key.
Here is my code:
/* Example of using sigaction() to setup a signal handler with 3 arguments
* including siginfo_t.
*/
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
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I was trying to program using fork(). The objective of this code is to
1. I am activating a process A - SubSuctionMotors.
2. Process A is going to stop with either of this condition
a) Switch is activated - swret=1
b) Time allowed has expired
3. Stop the process A.
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1. We purposely force the switch to be inactive to test the child process (timer), whether after 2 seconds the motor stop. It turns out to be successful in first few attempts. After some while, the program hang, nothing is executed anymore and the program is not exit or terminated. What can cause the program to hang?
2. We tried to stop motor by switch activation (if the switch is to be successfully activated, the time it takes will always be shorter than the timer allowed time). However, the program did not seems like noticing the switch has been activated, and it just stop the motor according to timer. Why it behave this way?
#!/bin/sh
trap "echo Haha" SIGUSER1
echo "asit"
count=1
while [ $count -le 10 ]
do
echo "Loop #$count"
sleep 10
count=$[ $count + 1 ]
done
echo "This is the end"
Why this is showing following error?
trap: 3: SIGUSER1: bad trap
I'm just beginning to program with GTK+, and I'm facing this issue: I want to inhibit a signal emission inside one and only one function. I've down cut my code into the smallest example I can to show you what I want to do:The "Emitter" contains a "GtkSpinBox" and it relays the "value-changed" signal, it's header:
Code:
#ifndef EMITTER_H
#define EMITTER_H
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Basically I'm intending to write serial RX signal handler.Application receives defined packages of data over serial which contains header and payload. Handler should analyse incoming stream and upon detection of header (header is 6B in length) switches to receive payload of length defined in header, then after receiving full message packs it and sends to application for handling.Problem I'm facing is that at random moments in signal I receive errors that "Resource temporarily unavailable" while reading from ttyOx device and I see that sometimes I miss incoming data.Also is it possible that if while I'm handling signal one more signal arrives and it is started to be handled parallel? If it is, what are the ways to prevent it? So I would be sure that no more signals will fire on same peripheral until I will finish handling what I have on my hands now.
Serial open and init:
Code: Select allint open_port(int port_nr) {
  int fd; /* File descriptor for the port */
  switch (port_nr) {
  case 1:
    fd = open("/dev/ttyO1", O_RDWR | O_NOCTTY | O_NDELAY);
    break;
 Â
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I'm learning Signals, and I have a question:
Is possible to make a handle when I press any of the keyboard buttons?
The SIGINT handles the Ctrl-C combination, but I want to handle if any keyboard button was pressed.
locking mutex (phtread_t type) in a signal handler function (installed by function signal()) for Linux. It seems that if the mutex has been previously locked by another thread outside the signal handler function and then the signal handler function tries to lock it, the whole process hangs.
View 5 Replies View RelatedI'm new to Unix and every signal handler algorithm I've seen is more or less a copy of what I'm trying to do.[URL] designing a signal handler with sigwait in UNIX?
View 1 Replies View RelatedI have a problem with the last point of some homework I have for an OS class. I need the program to print the pid upon execution, then for 10 seconds react to SIGUSR1, SIGUSR2 and SIGTERM. If either USR1 or USR2 is received, the 10 seconds are reset. Some of the functions I'm told to use are alarm(), pause() and signal(). The nicest way I found was to handle SIGUSR1, SIGUSR2 and SIGALRM in the parent process, with SIGALRM killing the child (with a SIGTERM). In the child a pause() (or for(; pause() would be enough for it to be alive until killed from the SIGALRM handler in the parent.
What I found is that I can't just do a wait() in the parent process, waiting for the child to be killed, since whenever the parent receives a SIGUSR1 or SIGUSR2, the right handler is called but the child exits nicely. I tried blocking/ignoring those signals in the child, since the default behaviour for SIGUSR1 and SIGUSR2 is to terminate the process, but the result is the same. The only way I could do it is using a waitpid() within a do { } while(!WIFSIGNALED(status)) since when the child gets killed with the parent's kill(), it's WIFSIGNALED, whereas when it exits after the parent handles a SIGUSR1/2, it's WIFEXITED.
P.S. What I'm doing to achieve the expected 10s window is calling alarm(10) in the parent process and again within the SIGUSR1/2 handlers. In the SIGALRM handler I kill the child and within the child I simply do a for(; pause()
I am using an imx27 and have a timer set up for 100 ms and a loop to count the pulses while the timer has not expired. I get about 90 % reliable results but every once in a while i get one that is out to lunch. I am reading in a signal that is about 500khz and counting on an transition. I usually get around 85k count. But i will randomly get a 50k count.
View 3 Replies View RelatedWhenever my computer's idle for about 2 minutes, it automatically goes to the login screen. How do I prevent this from happening?
View 4 Replies View RelatedI know this is not something that's usually done, but how do I stop a service like Apache only when I log on my user account?
View 4 Replies View RelatedIn a single main() function,so need signal handling. Use Posix Message Queue IPC mechanism , can ignore the priority and other linked list message,to implement the scenario:
View 1 Replies View Relatedwhen i press Alt+F2 then type "r" it rebuilds the gnome shell but when i do this twice it crashs with "oops something has gone bad" or similar to it. i press Alt+F2 then type "lg" to see what is the problem and in the error tab there is "Error : Error invoking Gio.make_directory_with_parents Cannot create directory : filed already exist".
View 6 Replies View RelatedI need to invoke one package namely "Size aware scheduling" in advanced version of NS2.34. In net they have given steps for installing it in older version NS2.18b. i have attached url for that package download. I followed the same steps as they said in note but couldnt install it NS2.34.
[URL]
1st url shows how the package work. second url shows from where the package should be downloaded and how to install it and all.
How can I, a single user, stop the hassle of having to constantly log in. Ubuntu 11.04 is what I currently using.
View 7 Replies View RelatedHow do I stop a user, from gaining access to the internet(port) via a restricted browser? In other words, I want a general user to only to have access to Firefox and no other browsers.
My first approach so far, has been to write a bash shell script. It terminates a program based on keywords from known browsers (opera, asus, ect).