A process is an instance of a computer program that is being executed.
3
votes
2answers
97 views
Is grandchild process also child process?
In Unix/Linux terminology, do child processes of a process include grandchild processes of the process?
2
votes
2answers
39 views
What is a process GID and what purpose does it serve?
Reading mod_wsgi's documentation I found you can choose which group to run the worker processes as.
I can understand group ownership of files and how only a user who belongs to that group can achieve ...
4
votes
3answers
45 views
Dynamic file content generation: Satisfying a 'file open' by a 'process execution'
I have a read-only file, F.
A program, P, that I'm not the author of, needs to read F.
I want the content of F to come from another 'generator' program, G, whenever P tries to read F (taking F to ...
0
votes
2answers
42 views
`ps | grep | kill` aborts my script prematurely [duplicate]
I have a Linux computer that I remotely SSH into using plink on a Windows XP machine. I have the Plink program set to execute commands in a script using automated login:
plink -ssh [domain name] -l ...
3
votes
3answers
34 views
Print process ID (PID) of a Matlab instance
To run my Matlab scripts, I've created a shell script to which I give two parameters - the path to the matlab file ($1) and to the log file ($2):
nohup time matlab -some_parameters -r "run $1;exit" ...
2
votes
4answers
62 views
Open program as root, close root session but still program is running
When I run my backup script, first I switch to root, mount a truecrypt partition and then run the script.
I've noticed that after run truecrypt as root, I can exit the root session and truecrypt ...
2
votes
3answers
141 views
Why does Firefox refuse to die despite killing it with pkill -9?
I am issuing the following command to kill Firefox on my Red Hat Linux box:
[subhrcho@slc04lyo ~]$ pkill -9 -f firefox
[subhrcho@slc04lyo ~]$
However, when I try to invoke Firefox through ...
0
votes
1answer
54 views
How to kill the (last - 1) PID with bash
I know how to kill the last process with
kill $!
However I would like to kill the last - 1 process, ie not the last one, but the one before the last one.
I tried
kill $$(($! -1))
but it ...
0
votes
0answers
37 views
Tracing system call on Ubuntu 12.04
The main task I have to carry out, is to trace the system call of processes in ubuntu 12.04 LTS.
Problem is, I am unable to trace them continuously, i.e. as soon as they are added to the system, they ...
4
votes
3answers
63 views
Can I pipe any two processes to each other?
In this page from The Design and Implementation of the 4.4BSD Operating System, it is said that:
A major difference between pipes and sockets is that pipes require a
common parent process to set ...
1
vote
2answers
350 views
Is nohup indefinite?
If I run a program with an infinite loop with nohup, will the program run indefinitely (until the machine is reset or until I manually terminate it)?
4
votes
2answers
861 views
Number of running processes show in top
The usual maximum number that I have seen in the "running" field displayed in top(1) is the number of logical CPUs installed in the system. However, I have observed that under Ubuntu 10.04 (not ...
-1
votes
1answer
38 views
System call tracing [closed]
I am working on system call tracing for host based IDS, i need to trace a process as soon as it entered in the system (a new entry in /proc). Is there any interrupt or signal or kernel datastructure ...
11
votes
5answers
2k views
What is using this network socket?
I'm trying to use NTP to update the time on my machine. However, it gives me an error:
host # ntpdate ntp1.example.org
10 Aug 12:38:50 ntpdate[7696]: the NTP socket is in use, exiting
What does the ...
2
votes
4answers
99 views
pkill can't kill processes with parent process id 1
I want to kill the following processes using
pkill "run_tcp_sender.sh"
or
pkill -SIGKILL "run_tcp_sender.sh"
root 14320 1 0 2012 ? 00:00:00 bash run_tcp_sender.sh ...
10
votes
3answers
1k views
Can I limit a process to a certain amount of time / CPU cycles?
We have a script which runs on our web servers, triggered by customer action, which initiates a unix process to generate some cache files. Because this process acts upon files supplied by our ...
3
votes
1answer
884 views
Understanding ps elapsed time format for long running processes
I'm using a ps command as part of an exercise to identify processes running longer than a given threshold.
I'm using the following template to get the elapsed time for a know process command:
ps -eo ...
1
vote
1answer
34 views
How to trace process scheduling of certain process?
For a project at my university I am researching ways to trace, log and manipulate the process scheduling of certain processes. I would like to launch an number of applications, everyone in a single ...
11
votes
2answers
879 views
Is there a way to intercept interprocess communication in Unix/Linux?
For intercepting/analyzing network traffic, we have a utility called Wireshark.
Do we have a similar utility for intercepting all the interprocess communication between any two processes in ...
1
vote
2answers
201 views
Discrepancy between reported used memory and sum of application memory usage
I'm running a desktop system that quite regularly suffers from lack of memory, this prompted me to investigate what causes the issue in the first place.
Problem is, there's no single process that ...
13
votes
3answers
1k views
How can I set the processor affinity of a process on Linux?
The question is all in the title: How can I set the processor affinity of a process on Linux?
1
vote
2answers
28 views
Single process accessible temporary file
I want to create a file that is only accessible to the process that created it (and potentially its children), and that disappears when the process exits, ideally never persisting the file to disk. As ...
4
votes
1answer
41 views
Suspend and edit previous single line commands
Say I want to modify the latter of some concatenated command line options, is it possible without killing the first command?
Specifically I have compile and run scripts executed thusly:
> compile ...
5
votes
2answers
126 views
What does it mean each process has a current directory?
I'm reading "The Unix Programming Environment", but I don't comprehend the concept current directory of process.
Each process, has a current directory, and all filenames are
implicitly assumed ...
4
votes
5answers
99 views
Is a persistent zombie process sign of a bug?
(OS: Debian variant.)
Having a process with zombie-status. The PPid belonged to a gvim process.
The contents of /proc/[pid]/wchan is do_exit,
/comm is sh and /cmdline is empty, /status is shown ...
4
votes
1answer
53 views
Kill user processess on logout
I have a Ubuntu server that handles remote X sessions from users. However, I don't want to allow users to run any kind of background processes - so here is my question:
How do I prevent users from ...
0
votes
0answers
29 views
dynamic pool of process C [migrated]
I'm writing program in UNIX on C. I have to write client-server(TCP) program on sockets. Client sends some information and server answer. No matter what client sends or receives because I successfully ...
7
votes
1answer
2k views
How to suspend and resume proccesses like bash does
this question is a follow-up to: How to suspend and resume proccesses
I have started firefox from a bash session in gnome-terminal.
The proccess tree looks like this:
$ ps -e -o pid,ppid,cmd -H
...
6
votes
2answers
451 views
Viewing foreground process using ps
I can see the background process using ps. But Is there a way to view the foreground process? For example,
$nohup process1 &
then
ps -ef | grep "process1"
would display the process ...
-1
votes
1answer
18 views
How to check the ports of Main and dependent Programs [closed]
we can see the ports using the Netstat -tulpn, e.g netstat -tulpn |grep program.
But what is there is program that has multiple modules dependent on main program. How we will know what ports are they ...
3
votes
3answers
2k views
Fork bomb on a Mac?
I just learned about a fork bomb, an interesting type of a denial of service attack. Wikipedia (and a few other places) suggest using :(){ :|:& };: on UNIX machines to fork the process an infine ...
3
votes
3answers
32 views
How can you change the process name of Wing IDE from python to something more descriptive
In my process list under Ubuntu (using top/System Monitor) one of the largest memory hogs (200+Mb) was python. I searched a bit for one of my programs to be the cause until I realised this was my ...
2
votes
1answer
124 views
How to find Heap memory of a running process? [duplicate]
I would Like to know how to find the heap captured of a process which is running in the background?
Is there any command by which you can find the process heap memory and here the process is still ...
2
votes
1answer
62 views
How to demonstrate invalid PID assumptions?
It seems many programmers are happy with saving a PID to a file, and then later read and use the PID as if it was guaranteed to be the same process. It seems the general idea is that the odds are good ...
1
vote
1answer
58 views
Do kernel counters for jiffies in state exist in Linux?
I am looking to get time/jiffie stats on the state of a daemon process. The states I'm referring to are mentioned in the Linux Kernel Proc Filesystem document. Running, Sleeping, uninterruptible ...
1
vote
1answer
49 views
List of killed processes HP-UX
Is there a file similar to the one in this answer http://unix.stackexchange.com/a/10078/5027 to determine the processes which were killed, in a certain time, for example, yesterday, in HP-UX?
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votes
0answers
48 views
Client-Server with unnamed pipes and select [closed]
I try to write simple client-server program using fork(), pipe() and select(). Parent process is a server, which select pipe with data from client by FD_ISSET and write data to other clients. And ...
2
votes
3answers
113 views
How do I start a process with a nice value of -20 and not give it root privilege?
I would like to start a process with a nice value of -20. This requires me to use a command like - sudo nice -n -20 matlab. However, this starts matlab as root too. Is there a way to have matlab as ...
0
votes
0answers
29 views
Pass process ownership to another shell [duplicate]
I didn't hear of anything like this, but It might be possible.
I often end up starting a process on a server and midway realizing that I would like to suspend that process and continue it inside a ...
1
vote
1answer
32 views
Looking for /procfs documentation, describing values and units of measurement
Surprisingly, comprehensive documentation for /procfs is hard to find.
For my specific question, I am looking at: cat /proc/1/statm (let's use pid=1 because it seems to be always there). I just ran ...
1
vote
2answers
45 views
Tracking which files are used by program
I am looking for a way to track which files are used by program installer(InstallAnywhere). I cannot use lsof because as far as I know it works on active processes and I want a tool which will work ...
1
vote
2answers
62 views
How to decrease ps aux output to a few lines?
When my computer is slowing down, I usually run ps aux --sort -rss to find out which process consumes too much memory. There may be a lot of processes. How to see only a few ones?
0
votes
1answer
57 views
Move terminal emulator process from xorg to tty? [duplicate]
Is it possible (and if so, how?) to move a process from a terminal emulator running in X to a different virtual terminal, so that I can restart the X server without killing the process running in the ...
0
votes
4answers
118 views
Show running processes with file name(s)?
I am using putty to connect my linux server which my sites are in. I can run
# ps aux | less
to show running processes. But I want to display which files running these processes ?
I have also ...
3
votes
1answer
639 views
A tee >( process ) is truncating its stdout when writing a file
When I use tee to pipe stdout directly to a "specific block of code" (which then writes the modified data to a file), I always get the full complement of exptected output lines in the file.
...
2
votes
2answers
69 views
End process from another SSH window
I forgot to use screen and I have a task that has been running for quite some time, and I do not want to lose the saved data. Basically Ctrlc will end the task and save the data if I am on the same ...
10
votes
2answers
376 views
Why does bash show 'Terminated' after killing a process?
Here is the behaviour I want to understand:
$ ps
PID TTY TIME CMD
392 ttys000 0:00.20 -bash
4268 ttys000 0:00.00 xargs
$ kill 4268
$ ps
PID TTY TIME CMD
392 ttys000 ...
1
vote
1answer
60 views
How to watch pgrep?
When running a pgrep command with watch it does not only show the actual pgrep output, but also the watch process as well.
Example:
watch pgrep -lf donothing
will show 3 processes, although
...
4
votes
3answers
233 views
Silently start task in background
I know that you can use this to start a process in the background, without getting the notification when the process is put in the background and when it is done like so:
(command &) &> /dev/null
...
1
vote
3answers
126 views
Block network access of a process?
Is it possible to block the (outgoing) network access of a single process?
