[SOLVED] Comapring variables using diff inside bash script

dinakumar12 · 03-27-2016, 06:39 AM

Hi,

I was searching to compare variables using diff command.

diff <(echo "$a") <(echo "$b")

when i use in bash shell it works.

But when i use the same command inside script it didnt. What i am missing here. Can any one Please suggest.

Thanks,
Dinesh.

Turbocapitalist · 03-27-2016, 09:15 AM

What is the first line of your shell script? Is it

Code:

#!/bin/sh

or is it

Code:

#!/bin/bash

or is it

Code:

#!/bin/zsh

If it is the former, then the process substitution <( ) will not work. Process substitution only works in a few shells, bash and zsh are the two that I know of.

dinakumar12 · 03-28-2016, 01:18 AM

Hi Turbocapitalist,

its #!/bin/sh and thats the reason it didn't work. Changed the shebang value to #!/bin/bash worked.

Thanks a lot for your tips. Is there any option to run the same sh shell environment.

Thanks,
Dinesh.

Turbocapitalist · 03-28-2016, 01:27 AM

You can run sh as your shell if you like. It'll be missing a lot of niceties though. Just run it from your regular shell:

Code:

/bin/sh

And then type 'exit' to get back to your regular shell when you are done. If you want the change to be permanent, use 'usermod' or the graphical equivalent.

dinakumar12 · 03-30-2016, 09:09 PM

I tried executing the script by sh scriptname to run in sh environement and yes its very linitted i guess. diff not working over there for comaring variables.

But its works fine with bash and thats what i ecpected.

Thanks for your response. Marking the thread as solved now.

Thanks,
Dinesh.