Question

So I want to automate a manual task using shell scripting, but I’m a little lost as to how to parse the output of a few commands. I would be able to this in other languages without a problem, so I’ll just explain what I’m going for in psuedo code and provide an example of the cmd output I’m trying to parse.

Example of output:

Chg 2167467 on 2012/02/13 by user1234@filename ‘description of submission’

What I need to parse out is ‘2167467’. So what I want to do is split on spaces and take element 1 to use in another command. The output of my next command looks like this:

Change 2167463 by user1234@filename on 2012/02/13 18:10:15

   description of submission

Affected files …

… //filepath/dir1/dir2/dir3/filename#2298 edit

I need to parse out ‘//filepath/dir1/dir2/dir3/filename#2298’ and use that in another command. Again, what I would do is remove the blank lines from the output, grab the 4th line, and split on space. From there I would grab the 1st element from the split and use it in my next command.

How can I do this in shell scripting? Examples or a point to some tutorials would be great.

Answer 1

Its not clear if you want to use the result from the first command for processing the 2nd command. If that is true, then

targString=$( cmd1 | awk '{print $2}')
command2 | sed -n "/${targString}/{n;n;n;s@.*[/][/]@//@;p;}"

Your example data has 2 different Chg values in it, (2167467, 2167463), so if you just want to process this output in 2 different ways, its even simpler

cmd1 | awk '{print $2}'
cmd2 | sed -n '/Change/{n;n;n;s@.*[/][/]@//@;p;}'

I hope this helps.