Tailing Rolling Files

Question

I have a directory full of rolling log files that I would like to be able to use tail on.

The files are named as such:

name      modified
00A.txt   Dec 2         


        

Answer 1

you may need inotify to detect the creation of the new file, a workaround for that would be to keep polling the filesystem while running tail on the background:

#!/bin/bash

get_latest() {
    local files=(*.log)
    local latest=${files[${#files[@]}-1]}
    echo "$latest"
    [[ $latest == $1 ]]
}
run_tail() {
    tail -c +0 -f "$1"
}

while true; do
    while current=$(get_latest "$current"); do
        sleep 1
    done
    [[ $pid ]] && kill $pid
    run_tail "$current" & pid=$!
done

(untested, unnecesarily hacky and be careful with the limitations of your old system!)

Answer 2

You can use the -F option for tail which implies --follow=name --retry.

From the man page:

-F      
The -F option implies the -f option, but tail will also check to see if the 
file being followed has been renamed or rotated.  The file is closed and 
reopened when tail detects that the filename being read from has a new inode 
number. The -F option is ignored if reading from standard input rather than 
a file.