How to run a command in the background and get no output?
ShellShell Problem Overview
I wrote two shell scripts a.sh and b.sh. In a.sh and b.sh I have a infinite for loop and they print some output to the terminal. I want to write another script which calls both a.sh and b.sh but I want the user to regain control of the terminal immediately, instead of having the script run infinitely and I want to hide the output in terminal.
Shell Solutions
Solution 1 - Shell
Use nohup if your background job takes a long time to finish or you just use SecureCRT or something like it login the server.
Redirect the stdout and stderr to /dev/null to ignore the output.
nohup /path/to/your/script.sh > /dev/null 2>&1 &
Solution 2 - Shell
Redirect the output to a file like this:
./a.sh > somefile 2>&1 &
This will redirect both stdout and stderr to the same file. If you want to redirect stdout and stderr to two different files use this:
./a.sh > stdoutfile 2> stderrfile &
You can use /dev/null as one or both of the files if you don't care about the stdout and/or stderr.
See bash manpage for details about redirections.
Solution 3 - Shell
Sorry this is a bit late but found the ideal solution for somple commands where you don't want any standard or error output (credit where it's due: http://felixmilea.com/2014/12/running-bash-commands-background-properly/)
This redirects output to null and keeps screen clear:
command &>/dev/null &
Solution 4 - Shell
Run in a subshell to remove notifications and close STDOUT and STDERR:
(&>/dev/null script.sh &)
Solution 5 - Shell
If they are in the same directory as your script that contains:
./a.sh > /dev/null 2>&1 &
./b.sh > /dev/null 2>&1 &
The & at the end is what makes your script run in the background.
The > /dev/null 2>&1 part is not necessary - it redirects the stdout and stderr streams so you don't have to see them on the terminal, which you may want to do for noisy scripts with lots of output.
Solution 6 - Shell
nohup sh -x runShellScripts.sh &
Solution 7 - Shell
If you want to run the script in a linux kickstart you have to run as below .
sh /tmp/script.sh > /dev/null 2>&1 < /dev/null &
Solution 8 - Shell
These examples work fine:
nohup sh prog.sh proglog.log 2>&1 &
For loop you can use like this :
for i in {1..10}; do sh prog.sh; sleep 1; done prog.log 2>&1 &
It works in background and does not show any output.