A process is an instance of a computer program that is being executed.

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Drop Process Privileges

I have a process that gets started by a damon running as root, now I want to "downgrade" this process's privileges to those of your average user. Is this possible? If yes how? PS: Running unix on a ...
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Under AIX, how can I get the full path of a program bound to a port?

Under Linux I can use netstat -tulpnw and ps, like so: # netstat -tulpnw | grep :53 tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 1482/named udp ...
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1answer
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How do you make a cross-process locking in Linux (C/C++)?

I need to make sure one process executes only in one instance at a time. On Windows you could use named mutex. But I have no idea what to use on Linux. I think I've seen an approach were app creates ...
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How to find which Process is causing High CPU usage

Is there any way to find out from terminal which process is causing high CPU Usage ? It would also be useful to order processes in descending order of cpu Usage
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How can I test if a program is running from within a script

Let's assume that another user started a bunzip process, and I have a script that I'd like to start running after that bunzip finishes. What's the best way to check from inside my script that the ...
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How to run java process to be seen not as 'java…' in processes list?

Is it possible to run a Java process in Linux in a way that it could be seen in ps as some sort of alias? It would be easier to restart it when it is down.
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All about ssh ProxyCommand

I am looking for an in-depth explanation of the following ProxyCommand, down to the nuts and bolts of its operation, please. Can you kindly completely dissect it for me and improve on it if you can? ...
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1answer
697 views

Using `pidof` with `sh -c`

I was wondering why this command line does not print pidof sh: $ sh -c "var=`pidof sh` ; echo \$var; ps -H" This one prints 123 as expected $ sh -c "var=123 ; echo \$var; ps -H" I am on Ubuntu ...
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Simple queuing system?

Given a commodity PC, we would like to use it to execute some tasks in the background round the clock. Basically, we would like to have commands like: add-task *insert command here* list-tasks ...
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248 views

start process so that it can't spawn new ones

Is it possible to start new process so that it couldn't spawn new ones (untrusted code)? Also how do I start a process so it couldn't make any input/output to files and in general any devices?
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How to kill two or more processes with one kill command?

I am using the following command to kill one java process via shell script: pidof java|xargs kill -9 $1 What if the list of pidof output has more than one elements? How do I kill them both with ...
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How to know how long a process has been running? [duplicate]

Possible Duplicate: How to check how a long a program has been running? I am interested in doing this purely using bash.
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Slow down just one process to regulate CPU temperature

I have a program. When it is running, the CPU temperature raise from 50 to 80 Celcius, which is my major concern. I can control the CPU frequency to slow it down, but other processes will be slowed ...
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Measuring RAM usage of a program

time is a brilliant command if you want to figure out how much CPU time a given command takes. I am looking for something similar that can measure the max RAM usage of the program and any children. ...
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37k views

Alternatives for “lsof” command?

In many cases "lsof" is not installed on the machines that with I have to work, but the "function" of lsof would be needed very much (ex. on AIX). :\ Are there any "lsof" like applications in the ...
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1answer
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What does this process STAT indicates?

If you check the STAT column in above image you will see Ss S S< SN and R+ What does this indicates ? Process states. If yes,Then what is the significance of 'Ss S< SN and R+'?
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What are “session leaders” in `ps`?

What are session leaders, as in ps -d which selects all processes except session leaders?
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1answer
332 views

Native and non-native support of thread/process programming in Linux?

POSIX thread (pthread) and OpenMP are both libraries for thread programming. But is it right that they are not native to Linux, i.e. they have to be installed by user later? If yes, what are the ...
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659 views

Which processes should I NOT strace?

I've created a little function for strace'ing a set of the current user's processes by name: function pstrace() { local pattern="$1"; shift; prefixDashP $(pgrep -U $(whoami) $pattern) | ...
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How to stop xargs from badly merging output from multiple processes?

I'm using xargs with the option --max-args=0 (alternatively -P 0). However, the output of the processes is merged into the stdout stream without regard for proper line separation. So I'll often end ...
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177 views

How to detect out-bound port from PID

I have several applications that run on random ports. How would I take the pid or the file location and find which port it is running on? Example of desired output: www-data/apache = 80 ...
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4answers
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What happens to the output of a process that has been disowned and lost its terminal?

If I close the virtual terminal, where some process was started, does the output just go straight to /dev/null, or can it pollute memory somehow? Can I anyhow grab the output to continue reading it at ...
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1answer
471 views

What is a zombie process? [closed]

Could you tell me the meaning of a "zombie process" and give an example.
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385 views

Kill process when it stops to produce further output

Is there a shell tool which can probe if a subprocess is still producing output, and otherwise kill it after a specified timeout? I'm using offlineimap for Gmail backup, but that's very very very ...
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1answer
674 views

Check for process already running in webfaction?

I use Django framework on webfaction and have 5 different cron jobs. One of them lasts much longer than others and sometimes gets stuck (30-120 seconds or more). I have already set that cron job to ...
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1answer
3k views

A more readable ps

Are there any tools that improve the readability of ps in the same spirit as ack for grep? This would be especially on OS X where ps does not even have options such as --sort user. So far the nicest ...
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1answer
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What is the maximum value of the PID of a process?

What is the maximum value of the PID of a process? Also, is it possible to change the PID of a running process?
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Find out what processes are writing to hard drive

On my Lenovo T400 and Ubuntu, the light for hard drive writing keeps flashing. I was wondering if in Linux it is possible to find out what processes are doing I/O to the hard drive? Just like by top, ...
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1answer
958 views

Automount lookup failed. How to determine what is trying to access the file?

Is there a way to find out what is trying to mount this file? Jul 13 14:27:24 myhost automount[13527]: lookup(file): lookup for tmp_dir failed Something is looking for "tmp_dir", and I've ...
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File descriptor limits are lost after a system reboot

I'm trying to increase the default file descriptor limits for processes on my system. Specifically I'm trying to get the limits to apply to the Condor daemon and its sub-processes when the machine ...
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1answer
136 views

Is there a way to determine which process creates a file on osx 10.6.8

I would like to know which process has created files on os X 10.6. I'm trying DTrace, which probably will give the right answer, but I have not eyes to see the method. I'm doing this because I think ...
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1answer
728 views

Make top shows only server process

Can I make top show info about the web and db servers? Can it be done by piping the pids to the top? They can be many process from every one?!? Or is there any better method for this?
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Who's got the other end of this unix socketpair?

I want to determine which process has the other end of a UNIX socket. Specifically, I'm asking about one that was created with socketpair(), though the problem is the same for any UNIX socket. I ...
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Removing zombie process from the process table

Can somebody please explain when parent process receives the exit status of a dead child process via wait, who actually reallocates the memory of the child process and removes it from the process ...
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Terminal command (called not from SU) that would restrict process from writting to all directories but one?

We have an app testApp. We have a folder called notRestricted in the directory where we run app from. We want to limit access of the app to file system so that app could write only to that folder (we ...
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Process descendants

I'm trying to build a process container. The container will trigger other programs. For example - a bash script that launches running background tasks with '&' usage. The important feature I'm ...
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What is a command line alternative to top for finding current CPU utilization that isn't dependent on screen width?

If I run top -p <myPID> -n 1 with a terminal that isn't wide enough, the CPU utilization % is omitted from the output. When trying to find a process' cpu utilization via bash scripting, this is ...
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2answers
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stop parallel processing for a cron triggered process

I have configured my webservers cron jobs to trigger some php script, every 15min, but sometimes the script takes morethan 15 min to complete execution, by the time another process of the same script ...
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view stdout for another pts

Here is the situation. I left my pc at home doing an rsync from a 2TB hard drive to another 2TB hard drive (it's going to take a while since they are both USB 2.0). I am now at work and I have ssh-ed ...
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1answer
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parsing process ID/names from /proc, thread IDs

When I'm parsing process IDs from /proc, obviously each thread of a process gets its own ID. And I realize that all the threads in that same process can be gathered from /proc/${pid}/task/. But my ...
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825 views

Finding out with which parameters a program was started

Is there a way to find out for any given process with which parameters it was started?
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3answers
1k views

How to monitor or kill a process which has been started by cron?

I have some bots, which are run by the System scheduler at given time interval. But sometimes due to some logical error I have to stop these bots manually. How can I find these processes run by the ...
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killall gives me `no process found ` but ps

Could somebody explain to me the difference between kill and killall? Why doesn't killall see what ps shows? # ps aux |grep db2 root 1123 0.0 0.8 841300 33956 pts/1 Sl 11:48 0:00 ...
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1answer
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Is there a way to tell which file (script, specifically) executed a command?

I'm running Slackware 13.37, and I was wondering if there was a way to tell which script executed a command. I tracked the process and its arguments, but I would like to know where the command ...
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2answers
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Need for thread_info structure in Linux 2.6 Kernel

Prior to the Linux 2.6 kernel, struct task_struct was present at the end of the kernel stack of each process. There was no thread_info struct concept. But in Linux 2.6 kernel, instead of task_struct ...
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How to determine which process is creating a file?

Given file path, how can I determine which process creates it (and/or reads/writes to it)?
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1answer
783 views

Solution to get data from memory of a process

If I'm using Firefox and filling out a big form (with lots of text to write), and for some reason I accidentally press F5 and all my text in the forms is lost, I can use e.g. HxD on Windows to ...
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Can you specify a separate trap in a subshell created with ()?

I'm writing a script that starts a subshell to go off and do some work. In a special case, the script needs to tell the subshell to cleanly stop what it's doing and exit early. However, my ...
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How to list only non-<defunct> processes?

Is there a combination of command-line options for ps or pgrep or some other relatively direct way to determine if a particular process name is actually running (available for normal use).. By ...
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Process Monitor equivalent for Linux?

Is there a Unix/Linux equivalent of Process Monitor, whether GUI or CUI? If it makes a difference, I'm looking at Ubuntu, but if there's an equivalent for other systems (Mac, other Linux variants ...