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

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add “check if fetchmail is running” to this script

while ! postqueue -p | grep -q empty; do sleep 1 done killall wvdial this script checks if my mail queue is empty, then disconnects my modem. now i would like to add also a checking to fetchmail ...
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1answer
531 views

There is no bash indicator prompt after a forked process terminates

I am reading the book Advanced Programming in the Unix Environment. There is a test program to test the fork function. It works well in my Ubuntu. But what I confused is that why there is no command ...
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1answer
5k views

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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1answer
2k views

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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2answers
1k views

How can I make a process I start during an SSH session run after the session has ended? [duplicate]

Possible Duplicate: Keep SSH Sessions running after disconnection. I have a process which is basically a web-server, I start it during an SSH session. However, when I leave the session (by ...
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2answers
51 views

How to know the source of a process in Linux?

In our firm, we are using Fedora 14. Our developers are using Python code to process documents. All are running as root. Somehow they did something and a file came inside which makes lots and lots of ...
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1answer
59 views

how to get the full command line args passed to a process on unix/linux systems? [duplicate]

I am looking for a reliable way to get the full command line args passed to a process even when these are very long. I do know about ps -f -p <pid> and /proc/<pid>/cmdline, both of which ...
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1answer
24 views

Re-enter PID 1 namespace

I'm trying to enter PID namespace that process with PID 1 is in from a process cloned with CLONE_NEWPID. I keep getting Invalid argument error. In other words, I clone a child process with clone() ...
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1answer
27 views

Is there a way to suspend an process belongs to shell A and foreground it in shell B?

I knew how to suspend one process and bring it into foreground in current shell, but I have no idea about that If I have run a process in shell A and now I want to bring it into foreground in current ...
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1answer
52 views

monitor multiple pids with top

I want to monitor memory usage for several processes and came up with a command like this: ps aux |grep -e postgres -e unicorn -e nginx|cut -d' ' -f2|for i in $(xargs); do echo $i; done 16112 16113 ...
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3answers
54 views

Controlling the environ passed to child process by bash

I am using x86_64 GNU/Linux with bash #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv) { system("set > setc"); // A subset of `$ ...
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1answer
90 views

strace works for some builtin commands

I'm trying to understand some kernel level concepts in Linux. I was checking on the difference between shell builtin commands and the other executable commands. This wonderful answer clearly tells ...
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1answer
6k views

I can't install new packages and can't update and upgrade

I'm trying to install some program on Ubuntu, but when I try it I got the following error.- E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock ...
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1answer
1k views

Why does't stopping the nginx server kill the processes associated with it?

When I stop nginx like this on ubuntu 12.04, I get the following errors: $ sudo service nginx stop Stopping nginx: nginx. $sudo service nginx start Starting nginx: nginx: [emerg] bind() to 0.0.0.0:80 ...
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1answer
303 views

How to renice a group of processes?

lb build can build live system image, and it invokes many processes while building the image. If I start it as below: # nice -n 19 ionice -n 7 -c 3 lb build all the children processes get the same ...
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1answer
634 views

How do I print the process name next to the process ID number in a file?

I'm redirecting results for something into a file and I also need to find the process name and ID number and redirect it to the file as well. I'm guessing the process name is the command in which I'm ...
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2answers
703 views

lsof - debug the output information

I was going through the questions of this site. In this particular question, I see the command lsof being used to list the files that are open for a particular user. I ran the below command in my ...
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1answer
2k views

child process does not inherit the pending signals from the parent after a fork system call, why?

Could anybody please tell me the reason to why pending signals are not inherited by the child process? On the other hand, the child process inherits the signal handlers and signal mask from the ...
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1answer
89 views

Run a script when a process throws stderr message

I want to "wrap" a process around another to catch stderr messages when they occur. Use Case I'm using Compass and I have to have a terminal open and see if there is something wrong. My plan is to ...
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1answer
209 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 ...
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2answers
729 views

Which script from /etc/init.d/ started the process?

Let's say we have a PID of a process and we know that it was started by init during startup. How do we find the script name that started it? One way is to run grep $PROCESS_NAME /etc/init.d/*, but ...
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1answer
503 views

Please explain the output from the jobs command

When I ran jobs command I see the following output : [1] - Suspended ./startWebLogic.sh [2] + Suspended (signal) top What does -/+ indicate in the second column ? ...
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`[java] <defunct>` with defunct children -> Any way to collect them?

Relating to question : What if 'kill -9' doesn't work? I have following situation : zombie process with threads, not collected by init : [root@Arch64]# ps auxH | grep java gwpl 569 ...
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1answer
263 views

What's the best strategy to catch mystery process?

I have running processes on my server that get killed every night at midnight. It's at work, I'm not around when it happens and I don't have remote access. The kill occurs very predicably at 23:59 ...
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1answer
1k views

How often is PSS value updated for a given process in /proc/pid/smaps

So if n processes are sharing a library L with size M then the contribution to their PSS is M/n. Now imagine one of the process terminates. So the contribution would be M/(n-1). Q1: My question is ...
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1answer
856 views

How to track file change

nsswitch.conf file always corrupts somehow. I do restore from my backup every time it corrupt. When this file corrupts, its time stamp is changing. Now I wonder if there is a way to track that file ? ...
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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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2answers
437 views

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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3answers
503 views

process that only root can run

I have created a process and it is running in the background as a daemon it.Now I want that only root should be able to view the output of that process.My process is something like "top" which ...
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2answers
24 views

Can someone explain exactly what is happening with single quotes and double quotes with process IDs in the below example? [duplicate]

[root@localhost ~]# echo $$ 16991 [root@localhost ~]# bash -c "echo $$" 16991 [root@localhost ~]# bash -c "echo $$" 16991 [root@localhost ~]# bash -c 'echo $$' 21062 [root@localhost ~]# bash -c 'echo ...
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1answer
38 views

What's the easiest way to detect what signals are being sent to a process?

I'm trying to debug an issue with my shell (specifically, fish) sending signals to my background processes. I'd like to be able to recognize what signals a process is receiving. Ideally, I'd like ...
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1answer
37 views

Creating symlinks in the etc directory without root access

What I would like to create if I had root access would be a symlink from some file or folder in the /etc to another file or folder in the /etc. However, I do not have root access. Is there any way to ...
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1answer
50 views

Get total bytes sent by pid

I have some processes in my unix system that sends data to a remote machine. It is possible to fetch the total bytes sent per pid ? In general, how i can monitor that pid in terms of network? Thank ...
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1answer
117 views

“incrond dead but subsys locked” what does it mean?

While running "service incrond status" it shows "incrond dead but subsys locked". Can you please tell me what does it means. Normally its status should be running. Let me know what may cause it to ...
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3answers
956 views

CPU and Memory usage monitoring for a single process

I need to monitor the CPU and Memory usage for a single process in an AIX server. The program runs 3 times a day. I need to find the way to capture statistics within some time intervals, lets say ...
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1answer
2k views

kill pid is not working? [duplicate]

This is pretty weird now. I am trying to kill a process by using its pid but it is not working at all. root@machineA:/home/david# ps aux | grep modelling david 5075 0.0 0.0 1285420 29404 ? ...
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2answers
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High Idle CPU / Low CPU Load average

After removing APC (alternative php cache), I noticed that there are less pagination access and less dirty pages but in the same time: High idle CPU Very low CPU load (relatively to the time before ...
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1answer
133 views

Application lags if started from init.d?

I have a program (pre-compiled binary) that, when started manually on linux, runs fine. It has a CLI that I use to enter commands. This program is a software router, I can connect to it's CLI to ...
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2answers
1k views

Determine what java applications are running within the java process name

I am writing a Built System for Sublime Text 3 for JavaScript unit testing. I am using js-test-driver as my testing framework. Sublime Text can only execute one command, so I am using a bash script to ...
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2answers
1k views

Find the PID's of all threads of a process without ps or pidof

So the system I'm working on (BusyBox) has a ps that takes no command line arguments and pidof returns nothing even though it exists within /sbin and points to killall5. Another issue I had is that ...
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1answer
2k views

How to check the status of bash shell script while executing from Python script?

I have a simple Python script which will execute a shell script using subprocess module in Python. Below is my Python shell script which is calling testing.sh shell script and it works fine. import ...
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2answers
651 views

AIX open() : file descriptor is zero (!?)

A daemon process, on detecting the presence of a text file in a particular directory then launches an executable file which opens the aforementioned text file in order to read and then transmit its ...
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4answers
1k views

Process is eating all of the CPU time

Is there any magic command to track down which process is starting this perl task that is eating 100% of CPU time? I have this problem on several machines where JBoss AS is installed.
2
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1answer
335 views

pmap and memory usage

On Ubuntu 12.04, I have several apache2 processes running (the 1130 parent and the children it spawned), and as you can see, they have around 300-400 mb of virtual memory and 10 mb of resident memory: ...
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1answer
656 views

How does One Find the PID of a Process Started with startproc?

My understanding is that it's generally a good idea to create a PID file for daemon processes and that startproc is a good way to start these daemons. I know that startproc takes -i and -p arguments ...
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1answer
1k views

What is the `ucond` process state?

When debugging a program I saw that top -U username showed the following: 39769 eigenein 107 98 0 179M 38448K ucond 19 0:00 0.00% program What does it mean that a process in the ...
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61 views

remotely query text file associated with an instance of vi

I have opened several text files (a.txt, b.txt, c.txt, ...) in different sessions of vi launched from different instances of a bash shell. Having then accessed that machine remotely, I wish to ...
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2answers
462 views

How to stop a infinite running process (ztail) started by a ssh session after that session is closed

I have a peculiar problem. My server supports multiple ssh session simultaneously, so that multiple admins can manage (via command line interface) it simultaneously. We have a command which calls ...
2
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1answer
139 views

Start and stop multiple executable for easy debugging

I'm debugging a networking project, which involves interacting of 3 programs, ie a server, two different clients. However I find it difficult to start and stop them for debugging. Some methods I have ...
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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 ...