Enter last directory in path and tail last file in directory

Question

I have on daily bases need to watch the logs during our testing. This is always a pain in the * as I always have to enter the log directory, copy the name of last directory, than copy the name of last log file in directory and tail it which takes a lot of time, I was wondering if there is any combination of commands which would do this automatically so I could alias it.

So I know to select last file/directory I can use this:

ls | tail -1

And I know to watch log file updating I can use:

tail -f

But is there a combination of commands which would go like this:

1. Select last directory in logs directory
2. Select last .log file in that directory
3. "tail -f" the last file in direcotry

Thank you for all your help.

Answer 1

To sort files by date reliably:

list_date_sorted_ascending() {
    while IFS= read -r -d '' -u 9
    do
        printf '%q\0' "${REPLY#* }"
    done 9< <(find "$1" -mindepth 1 -maxdepth 1 -printf '%T@' -exec printf ' %s\0' {} \; | sort --general-numeric-sort --zero-terminated)
}

To be able to use head and tail on NUL-separated output:

nul_terminated() {
    tr '\0\n' '\n\0' | "$@" | tr '\0\n' '\n\0'
}

Putting it together:

tail -f "$(list_date_sorted_ascending /var/log | nul_terminated tail -n 1)"

Answer 2

If your current working directory contains the log folders, you could try this:

dir=$(ls -dt * | sed q); tail -1 $dir/$(ls -t $dir | sed q)

(sed q is the same as head -1)