Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

Is there a command/program for OS X that allows me to hook to a file and display its changes in realtime without re-opening it, much like "top" monitors system processes in realtime?

share|improve this question

3 Answers 3

up vote 5 down vote accepted

You can use tail to monitor single log file.

If file is deleted, then created again you may want to use tail -F to actively monitor file changes

If same file is being appended too use tail -f to actively monitor file changes

share|improve this answer
    
It doesn't seem to display changes as the file updates –  Mark F Feb 6 '11 at 18:38
    
It does, at least on FreeBSD and linuxes. Should work on Mac OS X too. –  gelraen Feb 6 '11 at 18:41
    
@Mark how do you modify the file during checking? –  ulidtko Feb 6 '11 at 18:48
    
Perhaps it has something to do with the fact that the file is in a Dropbox and is updated perhaps a bit differently? –  Mark F Feb 6 '11 at 18:48
1  
Try tail -F. Consult with man tail for more details about these options. –  gelraen Feb 6 '11 at 18:51

Another alternative may be doing less the-interesting-file and hitting Shift+F.

share|improve this answer
    
Or less +F logfile –  Dennis Williamson Feb 6 '11 at 19:51

If you are doing this on file sync'd by dropbox the chances are it is creating a new file with a different inode so the tail -f command and the less +F command do not work since they are still referencing the old file handle they opened initially.

I suggest trying

watch "tail /path/to/filename"

It feels hackish but at least every X seconds it will re run tail on the filename giving you the updated output regardless of whether or not the inodes change on the file.

share|improve this answer

protected by Falcon Momot Nov 17 at 9:43

Thank you for your interest in this question. Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.

Would you like to answer one of these unanswered questions instead?

Not the answer you're looking for? Browse other questions tagged or ask your own question.