[NTLUG:Discuss] OT: head and tail

[Fred James]

All
(Off topic (?) : head and tail)

Starting with a 23,083 line text document, and wanting to discard 131 
line of the top and 5 off the bottom.
    head -23078 filename | tail -22947 > newfilename
right?  Wrong.  The resulting file was 473 lines, but ...
    head -23078 filename | tail +131 > newfilename
works as expected.

 From man tail (on IRIX):
" Tails relative to the end of the file are stored in a buffer, and thus
     are limited in length.  Various kinds of anomalous behavior may happen
     with character special files.  The tail command will only tail the last
     256 Kbytes of a file regardless of its line count.
 "
 From man tail (on SVR4 Release 4.0)
"          Tails relative to the end of the file are stored in a
          buffer, and thus are limited in length.  Various kinds of
          anomalous behavior may happen with character special files.
 
          The tail command will only tail the last 4096 bytes of a
          file regardless of its line count.
 "

Similar reading on Sun

... no such item in man on Linux.  But then, Linux doesn't have the 
option for 'tail +n', which is the solution on the others.

I didn't know that.
Regards
Fred James


-- 
Compassion alone stands apart from the continuous traffic between good and evil proceeding within us.  "Om Mani Padme Hum"