Questions tagged [signal]
Questions about signals, a kind of interprocess communication.
69
questions
4
votes
2
answers
404
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Detect that the workspace has changed
I can change my current workspace in various ways, e.g. by clicking on some switcher widget, with some key combination, with a command in a terminal.
Is there a way to detect that the workspace has ...
0
votes
0
answers
85
views
Tl-wn823n ubuntu 22.04 [duplicate]
Its connect but very week signal router is on desktop still week other device is work properly
1
vote
0
answers
193
views
Old version of Signal persists after update
Upon installing the latest version of Signal (6.16.0) the old and in-operable version (5.54.0) persists. Normally with other applications, the new version is installed and the old version is ...
1
vote
1
answer
262
views
Why does `/usr/bin/time` report the wrong exit status with format `%x` in case of SIGABRT?
I'm using /usr/bin/time to report information about a set of benchmarks I'm running. The interesting data points are runtime, memory usage and the exit status. This works fine except when the ...
3
votes
1
answer
854
views
remove Signal in ubuntu when you forgot how you installed it
i don't remember how i installed Signal desktop. i think i did it with ubuntu software.
the version is v1.39.6
so i removed it with all the ways i know
as if installed w/snap but it says here that ...
0
votes
0
answers
71
views
Uhuntu 22.04 monitor problem.... Monitor is not connected
I am a new user at Ubuntu and just today's morning I installed in on my computer dual boot with windows 10 when ever I try to open my pc the monitor works fine with windows 10 but when I boot uhuntu ...
0
votes
0
answers
69
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What is the correct way to see what signals a process handles?
EDIT: Since my question was not clear let me reformulate: how can one find what signals a process handles? From this answer: https://unix.stackexchange.com/questions/85364/how-can-i-check-what-signals-...
1
vote
1
answer
2k
views
Postgresql service stopping on its own in ubuntu server
In the postgresql log file, I found message:
startup process (PID 1886772) was terminated by signal 9: Killed
Although upon restarting service, postgresql database starts functioning normally. ...
0
votes
0
answers
28
views
On attempt to install Signal, I think I made some mistake and now getting some error in Ubuntu 20.04 LTS. How to correct this? Thank you [duplicate]
On sudo apt update command I get the following output:
> sudo apt update
[sudo] password for chess:
Hit:1 http://ppa.launchpad.net/alexlarsson/flatpak/ubuntu focal InRelease
Hit:2 https://...
1
vote
1
answer
223
views
Notification when some input (stdin, file, named pipe) is available? [closed]
is there some mechanism to be notified asynchronously when input from a 'file' is available?
I have a program that cyclically does its work. So far so good. But there also is a serial line and ...
0
votes
1
answer
389
views
Input signal out of range Change settings to 1600x900 60 [duplicate]
Ubuntu was working fine till i changed the resolution to one that was higher than the recommended settings(1600x900) now i don't know what to do. Any help?
5
votes
1
answer
930
views
Make gnome-terminal request user confirmation before close
When you open gnome-terminal without any options and execute a blocking command (e.g. python3, vim or cat) and then try to close the window by the close button (i.e. x button in the title bar) or some ...
7
votes
2
answers
36k
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Why does Ctrl + C not kill Python running in terminal?
I am trying to understand the reason why the whole Python process does not get killed when I press Ctrl + C inside and infinite loop or for that matter any Python function that I am running in ...
1
vote
1
answer
1k
views
HDMI monitor not receiving signal after waking up from suspend mode
i have a problem that after I wake my ubuntu 18.04 laptop from the suspend mode, my HDMI monitor, which is set up a the primary monitor in the extended display set up, is not receiving the signal.
I ...
1
vote
3
answers
2k
views
Is there any conflict between nohup and mpirun?
I want to start a big simulation on an ubuntu desktop computer. I have physical (not remote) access to this PC. This simulation may take some weeks. The command to start the process is:
mpirun -np ...
1
vote
0
answers
164
views
half signal strength from wireless rtl8188ce lubuntu
I get super slow speeds (half the signal strength I get on windows) and an unstable connection. I ran this script and this is the info I get on Lubuntu 19.04 Kernel 5.0.0-29-generic.
02:00.0 Network ...
0
votes
0
answers
590
views
How to move one process from SWAP to RAM?
As far as I can see, there is a design error in how my processes are moved between SWAP and RAM:
If RAM gets full, some are moved to SWAP. So far so good. But if RAM gets freed, they are not moved ...
1
vote
1
answer
55
views
What does it mean when ^\ doesn't work, but kill -9 does?
Recently, I've had a third-party program hang in a weird way. It stops taking input or output, and ^C and ^\ do nothing. kill -9 and killing the parent process do end it.
What state could the process ...
1
vote
1
answer
280
views
SIGQUIT breaks the pipe
Linux ping utility can produce some statistics on receiving SIGQUIT without terminating. It looks like this:
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=45 time=...
0
votes
1
answer
1k
views
Synchronize Signal contacts on signal-desktop in Ubuntu 18 from Signal on Ubuntu Touch (Fairphone2)
I installed the Signal app on my Fairphone2 running Ubuntu Touch.
Contacts were correctly imported from contacts list to the app.
I installed the Signal desktop client for Ubuntu 18 on my computer ...
0
votes
0
answers
20
views
Difference in Wifi connection %'s?
This is something I've wondered about for a long time...Ubuntu 16.04 using Cinnamon. On a tower computer.
In the action bar I have the Wifi icon. It shows that I'm currently connected to the local ...
1
vote
0
answers
43
views
Which version of Signal Desktop is legit? [duplicate]
I saw both of these in the apt sources. Since this is a secure communications app, what is the correct source to use for Ubuntu? Searching for Signal, I see:
And lower:
With these details:
Before ...
1
vote
0
answers
394
views
Multiple repository errors when I try any APT command after trying to install signal [duplicate]
I am currently using 18.04.
I wanted to install signal for desktop and I got this code from the site to install on Debian:
curl -s https://updates.signal.org/desktop/apt/keys.asc | sudo apt-key add ...
0
votes
1
answer
1k
views
Send multiple kill signals to a process
Say I run a .sh process. And now I open a new terminal tab and I want to send signals to it, for that, I just use kill:
kill -*signal number* *pid*
right? But I want to send 13 signals at the same ...
1
vote
1
answer
777
views
Signal messenger app not starting up
Over the past 2 weeks (after installing Ubuntu 18.04 from scratch) I have had problems on and off with the Signal messenger app. It sometimes doesn't start up at all. Uninstalling and reinstalling ...
2
votes
2
answers
1k
views
Sending SIGSTOP or SIGCONT signals graphically (similar to xkill)
Question
Do you know any tool/script to send SIGSTOP (to pause a process) or SIGCONT (to resume it) to a process by clicking on a graphical window generated by the process?
Some context
There is ...
0
votes
1
answer
630
views
Week wireless signal in Linux mint [closed]
After installing Linux Mint 18.3 "Sylvia" - Cinnamon (64-bit) on my HP laptop, I realize that the WiFi signal is a way too weak and the modem and the router is near my laptop.
Model: HP Probook 4540s
4
votes
1
answer
7k
views
How can I get yarn to use the right version of Node?
I am new to Node, JavaScript etc. and want to try messing with the code of Signal. For this I need a specific version of Node. I did this (on Ubuntu 16.04) using the following procedure:
wget https://...
1
vote
0
answers
436
views
Upstart service killed by TERM signal, how to track that
I have upstart script as
description "My API API"
author "me@localhost"
env MY_API_PYTHON_HOME=/opt/services
start on runlevel [2345]
stop on runlevel [!2345]
script
mkfifo /tmp/my-api-log-fifo
...
1
vote
1
answer
3k
views
Ubuntu 16.04, hdmi monitor: no signal in login screen
My main monitor is connected over HDMI and my second one over DVI.
Both get a signal when the PC starts up, but the moment I get to the login screen the HDMI one goes dark, though it doesn't seem to ...
0
votes
1
answer
231
views
Chromium Signal App crashing in Xubuntu
When I try to launch Signal through the launcher on Linux with the following
/usr/bin/chromium-browser --profile-directory=Default --app-id=bikioccmkafdpakkkcpdbppfkghcmihk
It crashes, nothing ...
2
votes
0
answers
135
views
Ubuntu 16.04LTS Four monitor display issue
I've been browsing the forum trying to find a solution to my specific problem but can't find anything specific. My graphics card is the Radeon R9 380 Sapphire Nitro. I have three DVI displays, one of ...
0
votes
1
answer
176
views
Why sigset includes unadded SIGINT? [closed]
Wrote simple program to learn writing POSIX style signal handling.
#include <signal.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
static void sig_int(int);
...
2
votes
1
answer
311
views
Disable "System program problem detected" for segfaults in my own programs
I don't mind being notified about system programs that SEGV -- I would actually like to report those cases, so this is not a duplicate of Getting “System program problem detected” pops up regularly ...
0
votes
1
answer
3k
views
Weak WiFi signal in Ubuntu on HP G240 G5 [duplicate]
I had purchased new HP 240 G5 laptop. Wifi is working good with windows but in ubuntu 16 wifi signal comes very weak. Below are laptop wifi details,
*-network
description: Wireless interface
...
1
vote
0
answers
85
views
Ubuntu 16.04 immediately terminates all running programs on restart or shutdown?
When I choose restart or shutdown in Ubuntu 16.04, it immediately terminates all running applications. I'm not prompted to save open documents or anything like that - and I've lost work several times ...
0
votes
2
answers
692
views
How to pass SIGALRM to a program which finishes execution in milliseconds?
I have a C program which computes the first n prime numbers if n is passed as an argument.
$ ./prime 5
2
3
5
7
11
The logic of the program allows me to enter into a desired function if I can give ...
2
votes
1
answer
3k
views
No SIGTERM before SIGKILL/shutdown with systemd on Ubuntu 16.04
I ran across this problem while I tried to answer a question on Stackoverflow.
On shutdown, Ubuntu 12.04 sends SIGTERM to all processes and waits at most 10 seconds before killing them with SIGKILL (...
2
votes
1
answer
634
views
After upgrade to 16.04, wifi signal strength jumps from perfect to zero and back
I upgraded from 14.04 LTS to 16.04 LTS on HP Z230. Internet connection worked perfectly under 14.04 LTS. There were no hardware changes.
The computer connects to the router by a wireless usb device (...
1
vote
1
answer
971
views
xvfb-run hangs on trap/wait in Elastic Bamboo's Ubuntu 15.04 AMI on AWS
I'm trying to run some headless robot/Selenium tests via Elastic Bamboo using Xvfb, on Ubuntu 15.04 in AWS EC2. It works if I run Xvfb manually and then run the test...
export display=:99
Xvfb :99 -...
0
votes
2
answers
543
views
Ubuntu 14.04 wireless unstable and the signal is weak
I installed Ubuntu 14.04 LTS alongside Win8.1 and the wireless was unstable. I updated windows network drivers then it went better but the signal is still very weak and also sometimes network switches ...
2
votes
2
answers
2k
views
Wifi apparently connected, but webpages won't load
I'm running the latest Ubuntu 14.04.3, and my issue today is that my Wifi connection sometimes becomes really slow, and eventually disconnects. I tried googling around to see if I can get any good ...
0
votes
2
answers
1k
views
Difference between C programs and shell scripts receiving signals from fuser
I have written the shell script below for a lab in my college. It must look at a log file being upgraded frequently from another process and create a number of copies passed at invokation.
Here is the ...
0
votes
1
answer
2k
views
index out of range? [closed]
# load parameters file
yml = yaml.load(open(sys.argv[1]))
# imports
for pkg, functions in yml['imports'].iteritems():
stri = 'from ' + pkg + ' import ' + ','.join(functions)
exec(stri)
...
1
vote
0
answers
474
views
Why does sudo prevent catching SIGTSTP (Ctrl+Z)?
This program is written to catch SIGTSTP (Ctrl+Z) and bypass its normal effect, printing a message and returning to its normal operation instead of allowing its process to be suspended:
#include<...
1
vote
0
answers
71
views
The UBUNTU Graphics Catch 22
Trying to use a Live DVD to run Ubuntu 14.04.1, I get the "Monitor signal out of range" error.
I hit ctrl-alt-F1 to bring up the command line.
I do sudo nano /etc/default/grub and remove # from ...
-1
votes
2
answers
2k
views
12.04 wifi signal very weak
Ii am new people in Ubuntu
I am using 12.04 version , but my wifi signal very weak
My router beside me only , my signal also only 50% ...
Anybody know how to fix it?i have try to research solution, ...
1
vote
1
answer
3k
views
emit signal with custom type objects array parameter from c++ and receive in qml
I would like to emit a signal from a Qt C++ class which includes a parameter that is an array of custom objects (inherited from QObject) and receive the parameter in its qml slot, but i'm afraid it is ...
0
votes
1
answer
65
views
sigfillset is not setting signal bits
I am having this strange problem! My code is very simple.
#include<stdio.h>
#include<unistd.h>
#include<signal.h>
#include<stdlib.h>
main(...
1
vote
1
answer
3k
views
What do these Terminal Signals mean?
When I start to use a command to terminate an ongoing process, I can include a signal.
What is the difference between the signal 9 and the signal 15?