[SOLVED] Run set of commands in background in bash

mackowiakp · 09-12-2020, 11:26 AM

Lets take such bash script:

Code:

#!/bin/bash
-----
<begining of script>
-----
command1 ; command2 ; command3
-----
<rest of script>

How to run "command1 ; command2 ; command3" in background? I mean that to execute in background first command, when it ends run second and when it ends run third one.
Of course it is possible to place such set of commands in separate script and whole run in background using "&" directive.
But how to make it in original script?

Turbocapitalist · 09-12-2020, 11:32 AM

I would try

Code:

#!/bin/bash
-----
<begining of script>
-----
(command1 ; command2 ; command3) &
-----
<rest of script>

or

Code:

#!/bin/bash
-----
<begining of script>
-----
sh -c "command1 ; command2 ; command3" & 
-----
<rest of script>

Both of those will run the three commands in sequence in the background while the rest of the script runs its course.

MadeInGermany · 09-13-2020, 04:18 AM

A (subshell) is a complete shell code.

Code:

#!/bin/bash
...
# sub shell starts here
(
  command1
  command2
  command3
) </dev/null >/dev/null 2>&1 &
# main shell continues here
...

The redirections separate stdin,stdout,stderr from a terminal i/o.
If you run the main shell in a terminal then the sub shell will continue when you exit or logout.