Follow tail by name (fix for rolling logs with tail -f)

tail -F file
If you use 'tail -f foo.txt' and it becomes temporarily moved/deleted (ie: log rolls over) then tail will not pick up on the new foo.txt and simply waits with no output. 'tail -F' allows you to follow the file by it's name, rather than a descriptor. If foo.txt disappears, tail will wait until the filename appears again and then continues tailing.

15
2009-07-23 07:37:11

These Might Interest You

  • This command finds the 5 (-n5) most frequently updated logs in /var/log, and then does a multifile tail follow of those log files. Alternately, you can do this to follow a specific list of log files: sudo tail -n0 -f /var/log/{messages,secure,cron,cups/error_log} Show Sample Output


    5
    ls -drt /var/log/* | tail -n5 | xargs sudo tail -n0 -f
    kanaka · 2009-07-22 14:44:41 0
  • with discard wilcards in bash you can "tail" newer logs files to see what happen, any error, info, warn... Show Sample Output


    5
    tail -f *[!.1][!.gz]
    piscue · 2009-03-06 16:24:44 3
  • The `-q' arg forces tail to not output the name of the current file


    1
    find dir/ -type f | xargs tail -fqn0
    chickenzilla · 2009-08-21 18:05:12 1
  • Using +F will put less in follow mode. This works similar to 'tail -f'. To stop scrolling, use the interrupt. Then you'll get the normal benefits of less (scroll, etc.). Pressing SHIFT-F will resume the 'tailling'.


    127
    less +F somelogfile
    adamm9 · 2009-02-19 14:33:46 4

What Others Think

I love this command. Don't forget you can follow more than one file at once: tail -F error_apache.log error_php.log error_trac.log error_svn.log
rkulla · 427 weeks and 6 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands



Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: