How to make newer "tail" behave like older "tail"

rylan76 · 12-05-2007, 07:35 AM

Hi guys

How can I make my "tail" binary in a FC6 install, which takes this parameter

tail -n +486

behave like an older version of tail, i. e. where I can just specify

tail +486

to get the same result from the "newer" tail on FC6 as the old syntax would have elicited??

Thanks...

matthewg42 · 12-05-2007, 07:45 AM

I thought the old style was like this, "tail -486", not using a + character. I believe this still works with the GNU tools version of tail.

colucix · 12-05-2007, 08:29 AM

Actually, the old-style option was +N to print out lines from N-th to the end. The new-style option does not permit it anymore, even if -N can still be used. However you can force tail to conform to the old POSIX standard, by setting the following environment variable

Code:

export _POSIX2_VERSION=199209

I don't know how this affects other commands, anyway. You can try to look for more detailed informations on the coreutils site.

rylan76 · 12-07-2007, 03:05 AM

THANKS!!!!!

That last one was the key - much obliged!

colucix · 12-07-2007, 04:27 AM

You're welcome!

To be sure, you can avoid problems with other commands by creating an alias for tail

Code:

alias tail='_POSIX2_VERSION=199209 tail'

in this way the variable _POSIX2_VERSION will be set only for the execution of tail.