extracting single charachters

Shell Programming and Scripting
1

Hello!

brand new to unix (let alone scripting) I have come hit a step I can't seem to get around.

in a text file I have information such as :-

INFORM_USERS_IB COMPLETED llprod 20011003:100608

What I need to do is extract the 55th and 56t charachter, then insert a : then extract the 57th and 58th.. to give me an end result of:-
10:06

problem is how do I count of extract these charachters as they change frequently but *should* stay in the correct position??
(also does tab count as a single char?)

Or is there an easier way to reformat a date and time string?

Cheers,
James

2

I would just use sed, something like this...

line="INFORM_USERS_IB COMPLETED llprod 20011003:100608"
echo "$line" | sed 's/[^:]*:\(..\)\(..\).*/\1:\2/'
3

there are approximately 20 similar lines for each title
"INFORM_USERS_IB " and the times will update.
is it possible to format each line sequentially using the second line of code, that way bypassing the need to define changing lines?

thanks
.
. .

4

You lost me there, but the sed statement should work for any similiar line. I just posted an easy way to demo it.

The sed statement discards all characters up to and including the colon. The next two chars are saved. Then a colon is inserted. Then the next two chars are saved. Everything else is discarded.

So as long as the time is the 4 chars following the first colon on the line everthing should be fine.