Er, the original TAC was a BSD utility which was rewritten by Jay Lepreau at Utah (who also happens to be my boss)... The source for it that I have sitting around (1986) doesn't actually list a copyright, but I'm fairly sure that we're in control of the copyright for that version. The authors are listed as "Unknown off the net long ago, and Jay Lepreau". :)
It's likely to not be as fast as the newer gnu version, of course, but if you'd like, I can check on the copyright issue and plop you the source if it's OK. -Dave Lo and Behold, Kevin Day said: > > Because of licensing restrictions in our product, we are unable to ship with > any GNU/GPL'ed tools, so I'm forced to fix 'tail' rather than use tac. (I > saw tac, and agree that it is faster for this specific use) > > Any VM people wanna pipe up and make a suggestion so that I may make up a > patch? > > Kevin > > > > > [Charset iso-8859-1 unsupported, filtering to ASCII...] > > I'd suggest that you use "tac" from GNU textutils. > > > > Charles > > > > -----Original Message----- > > From: Kevin Day [mailto:toa...@dragondata.com] > > Sent: Wednesday, July 28, 1999 3:09 AM > > To: hack...@freebsd.org > > Subject: Replace/rewrite reverse.c for tail(1) > > > > An application I use quite often requires me to reverse the lines in the > > file to get the desired output. > > > > 'tail -r' appears to be very inefficient in it's use of mmap(). It mmap's > > the entire file in, which encourages the kernel to swap out the rest of the > > system to keep pages of the input file in memory. > > > > 58350 root 54 0 412M 85244K RUN 0:14 19.78% 19.19% tail > > > > Out of 128M of ram, it's swapped nearly everything else out to keep 85M of > > this 400M file in ram, even though it will never touch it again. :) > > > > I see two possible fixes for this. One could be madvise'ing periodically > > with MADV_DONTNEED. If I understand correctly, this would help a bit, right? > > > > Or, mmap smaller regions of the file, and keep moving the buffer. This would > > also help with files exceeding mmap's limits. > > > > > > Any thoughts? > > > > > > Kevin > > > > > > To Unsubscribe: send mail to majord...@freebsd.org > > with "unsubscribe freebsd-hackers" in the body of the message > > > > > > To Unsubscribe: send mail to majord...@freebsd.org > > with "unsubscribe freebsd-hackers" in the body of the message > > > > > > To Unsubscribe: send mail to majord...@freebsd.org > with "unsubscribe freebsd-hackers" in the body of the message -- work: dande...@cs.utah.edu me: an...@pobox.com University of Utah CS Department http://www.angio.net/ "If you haul a geek up a crack, you will bloody their fingers for a day... If you teach a geek to climb, you will bloody their fingers for life." To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message
