Find running daemons linux

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Now, if we use the information that I gave in my answer, we could find running daemons by searching for processes which run without a controlling terminal attached to them. This can be done quite easily with ps : $ ps -eo ‘tty,pid,comm’ | grep ^?

How do I know which daemons are running?

Verify that the daemons are running.

1. On BSD-based UNIX systems, type the following command. % ps -ax | grep sge.
2. On systems running a UNIX System 5–based operating system (such as the Solaris Operating System), type the following command. % ps -ef | grep sge.

What daemons are running Linux?

List of service daemons for Linux and Unix-like systems

• amd – Auto Mount Daemon.
• anacron – Executed delayed cron tasks at boot time.
• apmd – Advanced Power Management Daemon.
• atd – Runs jobs queued using the at tool.
• autofs – Supports the automounter daemon allowing mount and unmount of devices on demand.

How do I see what services are running in Linux terminal?

Method-1: Listing Linux Running Services with service command. To display the status of all available services at once in the System V (SysV) init system, run the service command with the –status-all option: If you have multiple services, use file display commands (like less or more) for page-wise viewing.

How do you check if a systemd service is running?

For instance, to check to see if a unit is currently active (running), you can use the is-active command: systemctl is-active application.

How do I check if a service is running in Linux?

Check running services on Linux

1. Check the service status. A service can have any of the following statuses:
2. Start the service. If a service isn’t running, you can use the service command to start it.
3. Use netstat to find port conflicts.
4. Check xinetd status.
5. Check logs.
6. Next steps.

How do I run daemons?

To start a daemon, if it is in the bin folder, then you could, for example, run sudo ./feeder -d 3 from the bin folder. hi, I have tested or used kill/killall to kill one deamon. But in a moment, the deamon will automatically restart(using bin/status, the status of the daemon is running).

How do I start daemons in Linux?

To restart the httpd Web Server manually under Linux. Check inside your /etc/rc. d/init. d/ directory for services available and use command start | stop | restart to work around….3.12. Starting and stopping daemon services.

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How do I see what services are running in Unix?

How do I know if Xinetd is running on Linux?

Task: Verify that xinetd is running Type the following command to verify xinetd service is running or NOT: # /etc/init. d/xinetd status Output: xinetd (pid 6059) is running…

How to list all running daemons in Linux?

How to kill a daemon process in Linux?

Are there any daemons running without root privileges?

How to get list of zombie and daemon process?

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How to List All Running Services Under Systemd in Linux

Linux systems provide a variety of system services (such as process management, login, syslog, cron, etc.) and network services (such as remote login, e-mail, printers, web hosting, data storage, file transfer, domain name resolution (using DNS), dynamic IP address assignment (using DHCP), and much more).

Technically, a service is a process or group of processes (commonly known as daemons) running continuously in the background, waiting for requests to come in (especially from clients).

Linux supports different ways to manage (start, stop, restart, enable auto-start at system boot, etc.) services, typically through a process or service manager. Most if not all modern Linux distributions now use the same process manager: systemd.

Systemd is a system and service manager for Linux; a drop-in replacement for the init process, which is compatible with SysV and LSB init scripts, and the systemctl command is the primary tool to manage systemd.

In this guide, we will demonstrate how to list all running services under systemd in Linux.

Listing Running Services Under SystemD in Linux

When you run the systemctl command without any arguments, it will display a list of all loaded systemd units (read the systemd documentation for more information about systemd units) including services, showing their status (whether active or not).

To list all loaded services on your system (whether active; running, exited, or failed, use the list-units subcommand and —type switch with a value of service.

# systemctl list-units --type=service OR # systemctl --type=service

And to list all loaded but active services, both running and those that have exited, you can add the —state option with a value of active, as follows.

# systemctl list-units --type=service --state=active OR # systemctl --type=service --state=active

But to get a quick glance at all running services (i.e. all loaded and actively running services), run the following command.

# systemctl list-units --type=service --state=running OR # systemctl --type=service --state=running

If you frequently use the previous command, you can create an alias command in your ~/.bashrc file as shown, to easily invoke it.

Then add the following line under the list of aliases as shown in the screenshot.

alias running_services='systemctl list-units --type=service --state=running'

Save the changes in the file and close it. And from now onwards, use the “running_services” command to view a list of all loaded, actively running services on your server.

# running_services #use the Tab completion

Besides, an important aspect of services is the port they use. To determine the port a daemon process is listening on, you can use the netstat or ss command as shown.

Where the flag -l means print all listening sockets, -t displays all TCP connections, -u shows all UDP connections, -n means print numeric port numbers (instead of application names) and -p means show the application name.

# netstat -ltup | grep zabbix_agentd OR # ss -ltup | grep zabbix_agentd

The fifth column shows the socket: Local Address:Port. In this case, the process zabbix_agentd is listening on port 10050.

Also, if your server has a firewall service running, which controls how to block or allow traffic to or from selected services or ports, you can list services or ports that have been opened in the firewall, using the firewall-cmd or ufw command (depending on the Linux distributions you are using) as shown.

# firewall-cmd --list-services [FirewallD] # firewall-cmd --list-ports $ sudo ufw status [UFW Firewall]

That’s all for now! In this guide, we demonstrated how to view running services under systemd in Linux. We also covered how to check the port service is listening on and how to view services or ports opened in the system firewall.

Do you have any additions to make or questions? If yes, reach us using the comment form below.

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How to list all running daemons?

From my question Can Process id and session id of a daemon differ?, it was clear that I cannot easily decide the features of a daemon. I have read in different articles and from different forums that service —status-all command can be used to list all the daemons in my system. But I do not think that the command is listing all daemons because NetworkManager , a daemon which is currently running in my Ubuntu 14.04 system, is not listed by the command. Is there some command to list the running daemons or else is there some way to find the daemons from the filesystem itself?

Are you sure it’s not listed? How are you checking? I can see it on my Debian. Note that the name is network-manager , not NetworkManager .

Yes. I am sure. Nothing related to the term network is listed. Also it lists anacron which is mentioned as not a daemon in its init script.

Anacron not being a daemon is more a question of semantics because it is not run constantly. It is still run as a service which is what you normally refer to as daemons. Please edit your question and i) tell us which Ubuntu you are running and ii) what exactly you mean by «daemon». What is your final objective here?

I suppose any service running in the background is a daemon. I mentioned anacron because it was said in /etc/init.d/anacron that it is not a daemon. My objective is to write a C++ program to list all daemons running in my system. For that I need to know which files to parse to get the details.

Well, if you define daemons as services, service —status-all is what you need. Ubuntu seems to treat NetworkManager differently. I get both networking and network-manager in the output of services —status-all on Debian but only networking on Ubuntu. I think you need to define what exactly you mean by «daemon».

3 Answers 3

The notion of daemon is attached to processes, not files. For this reason, there is no sense in «finding daemons on the filesystem». Just to make the notion a little clearer : a program is an executable file (visible in the output of ls ) ; a process is an instance of that program (visible in the output of ps ).

Now, if we use the information that I gave in my answer, we could find running daemons by searching for processes which run without a controlling terminal attached to them. This can be done quite easily with ps :

The tty output field contains «?» when the process has no controlling terminal.

The big problem here comes when your system runs a graphical environment. Since GUI programs (i.e. Chromium) are not attached to a terminal, they also appear in the output. On a standard system, where root does not run graphical programs, you could simply restrict the previous list to root’s processes. This can be achieved using ps ‘ -U switch.

Yet, two problems arise here:

• If root is running graphical programs, they will show up.
• Daemons running without root privileges won’t. Note that daemons which start at boot time are usually running as root.

Basically, we would like to display all programs without a controlling terminal, but not GUI programs. Luckily for us, there is a program to list GUI processes : xlsclients ! This answer from slm tells us how to use it to list all GUI programs, but we’ll have to reverse it, since we want to exclude them. This can be done using the —deselect switch.

First, we’ll build a list of all GUI programs for which we have running processes. From the answer I just linked, this is done using.

$ xlsclients | cut -d' ' -f3 | paste - -s -d ',' 

Now, ps has a -C switch which allows us to select by command name. We just got our command list, so let’s inject it into the ps command line. Note that I’m using —deselect afterwards to reverse my selection.

$ ps -C "$(xlsclients | cut -d' ' -f3 | paste - -s -d ',')" --deselect 

Now, we have a list of all non-GUI processes. Let’s not forget our «no TTY attached» rule. For this, I’ll add -o tty,args to the previous line in order to output the tty of each process (and its full command line) :

$ ps -C "$(xlsclients | cut -d' ' -f3 | paste - -s -d ',')" --deselect -o tty,args | grep ^? 

The final grep captures all lines which begin with «?», that is, all processes without a controlling tty. And there you go! This final line gives you all non-GUI processes running without a controlling terminal. Note that you could still improve it, for instance, by excluding kernel threads (which aren’t processes).

$ ps -C "$(xlsclients | cut -d' ' -f3 | paste - -s -d ',')" --ppid 2 --pid 2 --deselect -o tty,args | grep ^? 

. or by adding a few columns of information for you to read:

$ ps -C "$(xlsclients | cut -d' ' -f3 | paste - -s -d ',')" --ppid 2 --pid 2 --deselect -o tty,uid,pid,ppid,args | grep ^? 

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