UNIX for Dummies Questions & Answers

Hi

Can some one tell what does this sed command do


sed 's/[]*[]$//g

I am more curious on the highlighted part , can some one explain what does that mean.

Thanks
Sri

The final $ is an anchor, means end of the line. That's easy. Now the outer brackets:

Code:

[]*[]

mean "match any one of these characters".
E.g., if you have [abd], it will match any of the chars 'a', 'b', 'd'.
So the whole thing will strip (substitute with empty string) any trailing ],[,or * on the line (only one character).
'g' is unnecessary, because of the $ anchor, you cannot substitute any further.
And to make this syntactically correct, we need a closing single quote also.
Here:

Code:

$ echo 'sfj[dd]aa[][]*sd[667]qf[[]]*[]' | sed 's/[]*[]$//'
sfj[dd]aa[][]*sd[667]qf[[]]*[

To strip all the trailing ],[, or *, you just an *, quantifier:

Code:

$ echo 'sfj[dd]aa[][]*sd[667]qf[[]]*[]' | sed 's/[]*[]*$//'
sfj[dd]aa[][]*sd[667]qf