replacing a line with spaces
 

I have a line like

port = 2566

I want to replace it as

port = 8080

does anyone knows how to do this in shell script. when i tried to do this with sed
sed -i 's/port=.*/port='$3'/' /root/$2
it is not recognizing spaces , it works only if line is port=2566 .

any idea on how to do this?

If your line has spaces then your regex needs spaces, too.

thanks... I tried giving space but it dosent work.. :-(

Maybe it is a tab or a mix, try using character list instead:
The use of double quotes will help you use the variable you are passing in.

You can use this

sed -i 's/2566/8080/' FilePath

@munavar - only if we assume that it exists nowhere else in the file

using the '/^port/' in front of the 's/' statement only applies the change to lines that start with 'port'.