1
vote
1answer
60 views

Best way to determine piped command to shell script?

Given tree /some/directory | print.sh Is there any way for print.sh to know that "tree -f /some/directory" was called, without trying to parse pid processes?
1
vote
1answer
60 views

How to trace system calls being invoked after typing command?

This question is relevant to the question of 'what happens when we type a simple command on shell?' I posted earlier. (I thought it would be better to post it seperately. But if not, please let me ...
14
votes
2answers
739 views

What happens when we type a simple command on shell? [duplicate]

I have a simple doubt on execution of a simple command. As per my understanding, when we type a command such as ls on interactive shell, Shell interpretes the command. Shell creates a child process ...
5
votes
3answers
178 views

Understanding environmental variables in different contexts

Trying to understand the behaviour of the environment in Linux (Ubuntu 13.04 concretely), I've find different situations where setting envirionment variables are used or defined for/in different ...
1
vote
2answers
77 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
56 views

Script always runs two instances

I was just curious, what may be the reason why script run two instances when executed. Whenever I run my script foo.sh, and when I check using: $ ps -ef | grep foo.sh It always returns two ...
2
votes
1answer
86 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
2answers
56 views

Why does kill not have a parameter for file and not for port number?

If I want to stop a program given its tcp port number or its file or named executable, can I run something like kill -tcpPortNumber $1 where the parameter $1 is a tcp port number or kill -filename $1 ...
1
vote
3answers
111 views

A command which returns either a process ID, if running, or some other output if not?

I'm looking for a command that will give me the PID, and it's not running it should give me some output other than blank. In my program, sometimes the library I'm using gives blank output even if ...
1
vote
2answers
128 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` ...
60
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 ...
13
votes
3answers
1k views

Find out current working directory of a running process?

What command(s) can one use to find out the current working directory (CWD) of a running process? These would be commands you could use externally from the process.
1
vote
4answers
273 views

monitoring file changes + process access to files

I would like to see what's happening in my app server folders, which files are changed by process x or which *.war files has been changed (replaced/created) in last x minutes. I am software developer ...
2
votes
2answers
94 views

Absolute path to currently-running zsh?

Sometimes the output of ps -p $$ shows the absolute path to the currently-running zsh, % ps -p $$ PID TTY TIME CMD 1027 ttys005 0:00.11 /usr/local/bin/zsh but not always: % ps -p ...
2
votes
0answers
58 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
159 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 ...
4
votes
3answers
727 views

Possible to get SMS/text message notification when process ends/is killed?

There are scripts that will send an e-mail when a server process is finished. However, I do not want to check my email every so often just to see whether a job has finished. Therefore I'd like to get ...
1
vote
1answer
80 views

Find if a process terminates in a specific amount of time

I am running a program.Inside this program i run a specific command and i use ulimit command to terminate the running of that command if it exceeds an amount of time.To be more clear i run this: ...
4
votes
3answers
1k views

Terminating a bash shell script running in the background

I often use bash shell scripts to run simple commands for many different files. For example, suppose that I have the following bash shell script, called script.sh, that runs the program/command foo ...
6
votes
7answers
5k 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
227 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" ...
4
votes
1answer
44 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 ...
0
votes
0answers
31 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
106 views

What rules govern the parent-child relationship of processes launched by shell across a pipe?

#!/bin/ksh # start_service: start the service my_server_executable 2>&1 | my_pipe_following_shell_script & exit 0 After I run the above start_service script from command line, it is ...
4
votes
4answers
3k views

Running multiple nohup commands in background

Got two commands cmd1 and cmd2. Of the two, cmd2 takes longer to finish. Need to run cmd2 and then cmd1. Tried to run them in following way: bash$ (nohup ./cmd2>result2 &) && nohup ...
1
vote
2answers
93 views

Cron creates vim process but does not display vim

Under MacOSX 10.8.2 I am able to run vim as follows in the bash shell: /usr/bin/vim -c "normal G" -c 'startinsert' ~/.journal If I put the exact same command in a script: #! /bin/bash export ...
3
votes
2answers
210 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. ...
5
votes
1answer
137 views

Can I add to my groups in the current (shell) process? [duplicate]

If I add myself to a group, it applies only to newly launched processes. Actually it's more restricted than that; it seems to apply only to new logins. I'm not sure what the exact mechanism is, but ...
2
votes
1answer
199 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 ...
7
votes
1answer
211 views

What should interactive shells do in orphaned process groups?

(Re-posting in unix per the suggestion in http://stackoverflow.com/questions/13718394/what-should-interactive-shells-do-in-orphaned-process-groups) The short question is, what should a shell do if it ...
23
votes
4answers
1k views

What's the difference between running a program as a daemon and forking it into background with '&'?

What are the practical differences from a sysadmin point of view when deploying services on a unix based system?
1
vote
2answers
221 views

How to run linux process and come back to it later?

I'm trying to run a minecraft server on linux. Running the server starts an important interactive session. I can run the server in the background by appending & at the end of the command and log ...
16
votes
4answers
2k views

Is there a program that can send me a notification e-mail when a process finishes?

I am a computational scientist, and I run a lot of lengthy calculations on Linux. Specifically, I run molecular dynamics (MD) simulations using the GROMACS package. These simulations can take days ...
3
votes
3answers
177 views

“Virtual” shell, ie. jailing an user inside a process

The title might not say much about the issue at hand so let me get straight to the point. Let's assume I have a casual user who can log in to the system via SSH into a bash shell. I also have a PHP ...
1
vote
1answer
305 views

Korn shell timeout/kill script

I am trying to write a simple Korn shell script to execute a loading process. The process occasionally runs into connectivity issues, so I need to kill it if it runs too long. I have been trying the ...
3
votes
1answer
356 views

wait does not wait

If i have a file called myprogram containing sleep 200 date Run this in the background: $ sh myprogram & i want to know when myprogram has completed by using wait command $ cat >notify ...
6
votes
2answers
5k views

How to see how many context switches a process makes?

I want to see if my process makes a lot of context switches. I also want to see how manpulating task groups affects the number of context switches.
1
vote
2answers
840 views

Kill all processes related to an application

I have two processes that are temporarily spawned and I need to kill them. Here are the processes from ps aux david 38329 0.0 5.0 3916476 104624 s002 S 11:33AM 0:17.43 ...
1
vote
2answers
1k views

How to pass data outside process for zenity progress?

Usually this would be a question about how to pass data from a subprocess to a main process, but maybe zenity has some extra quirks so please focus on zenity. Example: #!/bin/sh ( echo "10" ; sleep ...
17
votes
4answers
10k views

How to attach terminal to detached process?

I have detached a process from my terminal, like this: $ process & That terminal is now long closed, but process is still running and I want to send some commands to that process's stdin. Is ...
4
votes
3answers
498 views

What is a subshell (in the context of the documentation of make)?

I'm reading a book about the make command and there is a paragraph: If any of the prerequisites has an associated rule, make attempts to update those first. Next, the target file is considered. ...
7
votes
3answers
898 views

How to stop a bunch of processes on unix fast?

How to stop a bunch of processes on unix fast. I can use ps/top, kill. If the number of processes is very large, I use shell script. Are there other ways, only one or two unix commands can do it ...
2
votes
1answer
543 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 ...
3
votes
3answers
278 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 ...
3
votes
4answers
6k views

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 ...
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
892 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. ...
4
votes
1answer
1k views

How do I tell a script to wait for a process to start accepting requests on a port?

I need a command that will wait for a process to start accepting requests on a specific port. Is there something in linux that does that? while (checkAlive -host localhost -port 13000 == false) ...
9
votes
4answers
12k views

How can I kill a particular thread of a process?

$ ps -e -T | grep myp | grep -v grep 797 797 ? 00:00:00 myp 797 798 ? 00:00:00 myp 797 799 ? 00:00:00 myp 797 800 ? 00:00:00 myp This shows the process ...
12
votes
2answers
1k 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 ...