Linux – Redirect output to subfolders that don’t yet exist

bashcronlinux

I currently redirect crontab script output to file in some folder that exists, like this:

echo "test" > `date "+/tmp/%Y%m%d_%H%M.log"`

I want to redirect output to subfolders, that maybe don't exists yet (.../year/month/..., so subfolders should be created:

echo "test" > `date "+/tmp/%Y/%m/%d_%H%M.log"`

How can I accomplish this?

Best Answer

Simply create the directory. The -p flag to mkdir achieves two things:

Create the entire path
Don't complain if the diretorry already exists

So:

mkdir -p  $(date "+/tmp/%Y/%m/") && echo "test" > $(date "+/tmp/%Y/%m/%d_%H%M.log")

Next time ask questions like this on unix.stackexchange please, it's a bit offtopic here.

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I generally put something similar to the following at the beginning of every script (especially if it'll run as a daemon):

#!/bin/bash
exec 3>&1 4>&2
trap 'exec 2>&4 1>&3' 0 1 2 3
exec 1>log.out 2>&1
# Everything below will go to the file 'log.out':

Explanation:

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Saves file descriptors so they can be restored to whatever they were before redirection or used themselves to output to whatever they were before the following redirect.
trap 'exec 2>&4 1>&3' 0 1 2 3

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exec 1>log.out 2>&1

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Best Answer

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