1
vote
2answers
38 views

Remove unneeded file lock in script

I have some script using flock executable. It works well. Problem is when this script calls another script, and it creates background process. In this situation background process inherits file locked ...
1
vote
2answers
40 views

Call background process back to stdout

Is it possible to "call" a background process output to be shown in the terminal? Example: cron starts apt-get to update the system and I want to see the output of apt-get
5
votes
1answer
79 views

Why does `bash -c somecommand` sometimes not leave a bash process?

On an Ubuntu 12.04, with GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu), I tried the following command: $ bash -c 'pstree -s $$' init───sshd───sshd───sshd───bash───pstree $ bash -c 'pstree ...
1
vote
4answers
108 views

How to set the process won't be terminated when the terminal stops

[Edit] Make it simple. I invoked java xxx... on Machine A using putty to connect from Machine B. However I cannot reach Machine B. How can I connect Machine A from Machine C to set the running ...
1
vote
1answer
41 views

getting pid of two last commands executed in background and do stuff

I wrote this bash: #!/bin/bash eval "(a command) &" pid1=$! eval "(while kill -0 $pid1; do .... ; done) &" #It creates file.txt after few seconds pid2=$! if [ -s ...
3
votes
5answers
681 views

Getting pid of bash script from itself

I have a bash script with doing lot of things called script.sh: #!/bin/bash #It #Is #Doing #Things Is there a way that I be able to get the proccess of script and then kill it after 5 minutes? ...
4
votes
2answers
134 views

How to kill a process started as daemon?

I start a process using foo &. It outputs something like: [1] 16915 This is the process id, I guess. How can I store this number into a variable named MY_PROCESS_ID (for example)? Then I ...
1
vote
2answers
184 views

Running a bash script as root prevents asynchronous execution?

The script below get's executed differently if run as a root user. #!/bin/sh gnome-terminal -x sleep 10 echo 'Why must I wait for sleep to finish?' If its run as a regular user, message is ...
1
vote
2answers
1k views

In bash script, how to capture stdout line by line

In a bash script, I would like to capture the standard output of a long command line by line, so that they can be analysed and reported while initial command is still running. This is the complicated ...
6
votes
1answer
3k views

There are stopped jobs (on bash exit)

I get the message There are stopped jobs. when i try to exit a bash shell sometimes. Here is a reproducible scenario in python 2.x: ctrl+c is handled by the interpreter as an exception. ctrl+z ...
0
votes
1answer
120 views

Full path name of bash? and base process of Linux?

I am new to Linux and I recently had a test at school which had the following questions: What is the full path name of bash? What is the base process of Linux? I couldn't answer these. Does anyone ...
0
votes
2answers
596 views

How do I run two ongoing processes at once in linux/bash?

I would like to know how I can run two ongoing processes at the same time in Linux/bash. basically, I have a Node web server, and a MJPG-Streamer server. I want to run both these processes at once, ...
1
vote
1answer
155 views

fg a bg process because you forgot to redirect output to /dev/null

I did Ctrl+Z bg with the intention of disowning next, but I forgot to redirect, now I cant get to my terminal because the scrolling of the output (tarballed a huge directory with verbose set). How do ...
1
vote
2answers
346 views

How to terminate a background process in Linux when the pid is unknown?

I have a job dispatcher bash shell script containing below codes: for (( i=0; i<$toBeDoneNum; i=i+1 )) do while true do processNum=`ps aux | grep Checking | wc -l` ...
3
votes
1answer
206 views

How does the piping in this command ultimately achieve to kill the process?

I have seen the following line in a bash script for killing a process(in this case started with the command loadgen): ps xww | grep -i "loadgen" | grep "PATTERNMATCH_FACT.xml" | cut -c1-5 | xargs -i ...
2
votes
2answers
47 views

Processes lose attachment to shell when started via bash -x

Normally, if I run emacs & and then close the shell, emacs will exit. However, if I run bash -x foo.foo (where foo.foo is a script that runs emacs &), then emacs will remain open even when I ...
5
votes
2answers
461 views

Obtaining PID of command earlier in Pipeline

I'm writing a bash script to use inotifywait to monitor a directory and kick off actions when changes are detected. Something like: inotifywait -m ... | while read f; do something; done Since ...
5
votes
2answers
590 views

Get the PID of file creation

I am writing a bash script that creates 5 files with the extension ".P" and write a line of "something" into them. "P" represents a number and it's the PID of the process that creates the file. How ...
70
votes
4answers
1k views

Can I somehow add a “&& prog2” to an already running prog1?

Most shells provide functions like && and ; to chain the execution of commands in certain ways. But what if a command is already running, can I still somehow add another command to be executed ...
5
votes
3answers
1k views

Use & (ampersand) in single line bash loop

I have been using this command successfully, which changes a variable in a config file then executes a Python script within a loop: for((i=114;i<=255;i+=1)); do echo $i > numbers.txt;python ...
3
votes
1answer
3k views

bash: Run command in background and capture pid [duplicate]

Am writing a bash 4.1 script... Would like run another script (or internal function) in the background... And capture the pid of that background job in a variable in the foreground script... If the ...
3
votes
2answers
569 views

Wait for background processes to finish with inverse match process ID

I'm looking to run a number of background processes in a loop, but only want to wait for all of those processes to finish, still allowing another background process to continue. After doing some ...
0
votes
2answers
253 views

Find PHP process that logs to file

I have started a PHP script via browser and due to a loop error the script continues to be executed even after closing the browser. I am noticing it since the script is logging error messages to my ...
2
votes
0answers
72 views

Linux child processes not being culled [closed]

This is causing significant problems for script portability between BSD and Linux. I am on a CentOS 6.4 where this happens. I have a nice compact test case: bash -c "inotifywait -mcr . | sed ...
1
vote
0answers
230 views

gnome-terminal cmd leaving processes open after closing parent window

The following simple command should demonstrate my issue: gnome-terminal --tab -t "Tab 1" -e "/bin/bash" --tab -t "Tab 2" -e "/bin/bash" This should open a new window with two tabs and an active ...
-3
votes
2answers
206 views

Bash operator & not working [closed]

As per the bash reference, we can give a non-blocking command by ending it with an ampersand(&) character. However, when I try the below command its not working: python -m SimpleHTTPServer ...
6
votes
8answers
8k views

Bash way to check if a process is already running in the background (and skip re-execution based on that)?

Can I make a bash command line that only runs a certain command if the process is not already running (in the background)? How do I check*, if a command is already running? (so I can add the next ...
3
votes
3answers
4k views

Fix “firefox is already running” issue in Linux

I am trying to open Firefox in CentOS, but I'm getting the following message: Firefox is already running but is not responding and Firefox doesn't open. I tried this in command line: kill ...
2
votes
1answer
602 views

How to check if a currently running process is opened by root or user

I'm currently creating a BASH script to kill off processes. I first check if the process is running then kill it. But I would like to add a nested if to find out if that process was opened by root ...
0
votes
1answer
397 views

Identify Tasks/Process which are 7 days old in linux

How can I identify the processes running since 7 days in Linux?
1
vote
1answer
833 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, i.e. not the last one, but the one before the last one. I tried kill $$(($! -1)) but ...
12
votes
2answers
2k 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 ...
4
votes
2answers
5k views

Bash script wait for processes and get return code

I am trying to create a script which will start many background command. For each background command I need to get the return code. I have been trying the following script : #!/bin/bash set -x ...
3
votes
2answers
276 views

$BASHPID And $$ differ in some cases

I'm reading "BASH pocket guide of Oreilly". It said: The process ID of the current Bash process. In some cases, this can differ from $$. Above explanation , explained $BASHPID variable. ...
1
vote
1answer
172 views

How to ensure a process has started reading a file before continuing?

I'm trying to write a command to test that data is written to a file. My first approach was: Start reading in the background. Write some data to the file. Wait for the reader to find a result. ...
2
votes
1answer
242 views

Can I transfer running process from dead ssh [duplicate]

Possible Duplicate: How can I disown a running process and associate it to a new screen shell? I have started (as expected) a long copy process from ssh shell (putty) which died due to ...
8
votes
4answers
8k views

How to view the output of a running process in another bash session?

I have left a script running on a remote machine from when I was locally working at it. I can connect over SSH to the machine as the same user and see the script running in ps. $ ps aux | grep ...
1
vote
2answers
170 views

receiving command as a parameter in bash

I have a following simple script called single-instance that executes the given command if there is no process under that command running. If I hard-code the command after the else statement, it has ...
0
votes
2answers
4k views

Get PID of a function executed in the background

#!/bin/bash function abc() # wait for some event to happen, can be terminated by other process { sleep 3333 } echo "PID: $$" abc & echo "PID: $$" I need to retrieve the pid of this function, ...
3
votes
1answer
341 views

bash: disable new process PID message

It may look like this: [2] 2847. I guess the first digit is just an enumeration of processes created from the shell. The second is the PID. Anyway, I never care about that information so it is just ...
2
votes
2answers
264 views

Quick and dirty way to run a process more than once

I am looking for very simple bash script that would allow me to launch a process a few times. What's essential to me is that after the processes terminate, everything will clean up automatically. ...
1
vote
1answer
129 views

How do you prevent user from opening a program?

I'm trying to write a script which prevents the concerned user from opening programs (mostly internet browsers) from being run during a certain time (like 1000 to 1200 hrs). This is like a ...
5
votes
1answer
233 views

Why is the following command killing a system?

Anyone understand the following code , running in bash ? :(){ :|:& };: It seems to be a "fork" bomb on Linux.
2
votes
2answers
351 views

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 ...
3
votes
3answers
1k views

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 ...
3
votes
4answers
899 views

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.
6
votes
1answer
1k views

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? ...
0
votes
1answer
3k views

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.
1
vote
1answer
2k views

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 ...
3
votes
1answer
1k 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. ...