Monitor logs in Linux using Tail

find /var/log -type f -exec file {} \; | grep 'text' | cut -d' ' -f1 | sed -e's/:$//g' | grep -v '[0-9]$' | xargs tail -f
Works in Ubuntu, I hope it will work on all Linux machines. For Unixes, tail should be capable of handling more than one file with '-f' option. This command line simply take log files which are text files, and not ending with a number, and it will continuously monitor those files. Putting one alias in .profile will be more useful.

6
By: mohan43u
2009-06-03 09:47:08

What Others Think

I've always wondered if I could tail more than one file. Can you break down each command and say what exactly is going on here?
Scott · 493 weeks and 5 days ago
In the long term, if you find this kind of consolidated log useful, consider changing your log settings to give you that in the first place.
citybadger · 493 weeks and 5 days ago
@Scott find is a generic tool for searching a path for files that match rules you specify and then possibly taking action. Here we are finding normal files (not directories) in /var/log (where log files live) and running 'file' on each of them which spits out the filename along with a description of file's guess as to each filetype. The grep|cut|set|grep combo just filters the text down to the filenames of actual text files, and, and then the xargs part just runs one instance of tail on all the resulting filenames. If you're on a unix system, you could test this on your system. To see the effect of each command just start with the 'find' part and then start tacking on the succeeding piped commands one by one. Don't forget to check the man pages too: 'man find', 'man file', etc.
bwoodacre · 493 weeks and 5 days ago
@bwoodacre, thanks for the explanation, I should have explained at first. I'll be happy if someone says, "Hey, its monitoring my ssh logs, apache logs, php logs, mysql logs etc.,". I didn't install them in my old machine.
mohan43u · 493 weeks and 4 days ago
Very neat command, I like it :) Thanks.
Weboide · 493 weeks and 4 days ago
You can also replace tail with inotail which will reduce the load. (because inotail uses inotify which is a kernel feature to get notified of file changes)
Weboide · 493 weeks and 4 days ago
grep, cut. sed and then grep again. Why not just sed? find /var/log -type f -exec file {} \; | sed -n '/text/ s/[^0-9]:.*//p' | xargs tail -f
unixmonkey8119 · 373 weeks 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?

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