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UNIX - Process/Jobs


Playing the commands fg , ctrl+z , bg and jobs


In this post I would like to share few basic process or job specific tricks in UNIX.

1. If you want to run a process in bacground just add a & as suffix with a space 

Eg:

[root@localhost kannan]# ruby test.rb &

here this process test.rb will run in background 

2. If you want list available background tasks/processes/jobs , just use the command 'jobs'

Eg:

[root@localhost kannan]# jobs

here the result would be 

[1]+ Running ruby test.rb 

3. If you want to bring a background process in front (foreground) just use fg [#<job number>]

Eg

[root@localhost kannan]# fg #1 

It will bring the above 'ruby test.rb' process in front.

4. If you want to again move a already running process to background , use two combination of commands
    a. First pass Ctrl+Z , here you will get a message like 'stopped' don't get upset, it will just suspend
    b. Do run 'bg' command will take the suspended process/job/task to background process 

Eg

[root@localhost kannan]# jobs
[1]+  Running                 ruby test.rb &
[root@localhost kannan]# fg #1
ruby test.rb
^Z
[1]+  Stopped                 ruby test.rb
[root@localhost kannan]# bg
[1]+ ruby test.rb &
[root@localhost kannan]# 



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