On Sun, 2012-05-06 at 21:02 +0430, Yasser Zamani wrote: > Thanks a lot Simon, > > As I cited, the book is well described enough but I worried a bit when > I saw a 'sed' script at first time. However, as the mailing list's > friends advised, after learning a bit online, now I don't have any > trouble with 'sed' expressions at book :) > > Here, I would like to write down what I learned just in few lines for > helping whom reach this thread via searching the mailing list: > > 1. sed stands for 'stream editor' > 2. Streams are bytes which are traveling e.g. byte[] is an array > but when you send it's items one by one to a destination then > it's a stream.
Better to say characters, than bytes. They *are* bytes, of course, but
as a tool for dealing with text, sed views the stream as a stream of
characters. And a character isn't always a single byte.
> 1. Exampl 2: echo 'Welcome to LFS' | sed 's@[A-Z]@*&@g'
> 1. A bit more complicated, right? but not at all
> when I describe it:
Oh, that's not complicated at all. Somewhat offtopic for LFS, but try
this one, used in a script I wrote for work... basically it parses and
reformats the output of our version control tools...
sed -n '
/version ".*"/h;
/activity:.*@/{
H; g
s/.*version "\(.*\)".*activity:\(.*\)@\/vobs.*/\2 - \1/
p
}'
Simon.
signature.asc
Description: This is a digitally signed message part
-- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
