Run Commands Simultaneously 1

[TamedTech]

Hello Guys,

I’m a little new to the whole Shell scripting process but I’m slowly learning.

I’m looking for a method to run two commands simultaneously in a script, what’s the best way of achieving this? Perhaps use something like the ‘while’ command?

Thanks,

Rob

 

[mrn]

You can use & to run commands in the background

while [ a = b ];do
netstat -rn &
ifconfig -a &
done

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

http://www.airport-parking-site.co.uk/

 

[TamedTech]

Ok that sounds good thanks mike,

So presumably I can add as many commands into that as i like and just add an & at the end and it will run them all at the same time?

Thanks,

Rob

 

[mrn]

Well not exactly at the same time, but as close as.

Just as point of interest have a look at the man page for nohup as well

man nohup

nohup allows your commands to kept running even if you disconnect your terminal session.

nohup command &

other useful operators are && and ||

ls && ps

&& allows the second command if the first was successful

so

zzzzzzz && ps

would produce an error zzzzzzz not found and would not run ps, handy if you want to make sure the first thing worked before you start the second.

ls || ps

would only run ls

zzzzzzz || ps

would run ps because zzzzzzz failed. Useful to clean up if things go wrong.

Mike

"A foolproof method for sculpting an elephant: first, get a huge block of marble, then you chip away everything that doesn't look like an elephant."

http://www.airport-parking-site.co.uk/

 

[TamedTech]

Thats excelent thanks mike,

I didnt end up requireing the WHILE statement, just stuck the & at the end of the commands i wanted to run and it ran them almost along side one another.

Achieved my goal nicely.

Thanks,

Rob