On Sun, Mar 30, 2014 at 8:31 AM, Raf Czlonka <[email protected]> wrote: > Hi all, > > Let me start by saying "Thank you" for the great job you are all doing > for the OpenBSD project and community. > > I have tried sending this email to www@ but it bounced (reported in a > separate email) hence, for a lack of a better place, resending it here. > > In the FAQ 2.4[0] there's an example of how to get the content of a > particular line from a file with the source code: > > # cat -n pf.c | head -n 3872 | tail -n 1 > > While, in this instance, it does not fall under the "Useless use of > cat"[1] (as the '-n' option provides line numbering) the command > construct in unnecessarily long (three commands instead of one). > > I can understand (I think) that the very reason of it being that > "complex" is the fact someone wanted for the line number to be included > in the output. This, however, is superfluous, as we explicitly "ask" for > the line in question while using 'head | tail' pipe, so the whole thing > can be shortened to: > > # head -n 3872 pf.c | tail -n 1 > > IMVHO, since the FAQ section is mostly aimed at new, often > inexperienced, users it may be a good idea to start them off with a good > habit of using the simplest tool for the job, instead of overly complex > constructs. > > One such way would be to use 'sed' instead: > > # sed -n 3872p pf.c > > I have included a small patch if you'd care to apply it to said page. > > [0] http://www.openbsd.org/faq/faq2.html#Bugs > [1] http://partmaps.org/era/unix/award.html > > Best regards, > > Raf > > [demime 1.01d removed an attachment of type text/x-diff] >
This sed syntax is WAY better, i guess the cat -n was explanatory and thats why it was use instead of directly passing the file to head. so because it is educational , i would put : cat -n pf.c | sed -n 3872p pf.c wihch self explain than line 3872 is printed. -- --------------------------------------------------------------------------------------------------------------------- () ascii ribbon campaign - against html e-mail /\
