check if folder exists

This piece of snippet code below will check if a folder exists.

Linux OS that has NTFS driver installed, can easily to plug in and plug out NTFS formatted external drives.

Or look for ntfs-3g driver if NTFS is not supported.

And can easily be used by both Windows OS and Linux OS.

This piece of snippet code below will check if a folder exists and execute a command if a folder is found.

In Linux world, depends on the distro you are using.

If you insert an NTFS formatted external drive you need to mount the drive.

Once the external drive is inserted type: df -h

Then you will have this output or it might be different in your distro.

/dev/sdb1   1.9T

Then you can proceed to mount the drive like:

mount -t ntfs /dev/sdb1 /media/Week1  (Week1 is the folder name, can be change to any name)

Of course there are other methods, if the command above will not work.

Type “man mount” (don’t include quotes when typing on the terminal) if you want to dig further about mount command.

For example if you have four drives for Week1 to Week4 rotational backup (monthly backup one drive for each week).

For readability and clarity purposes, its better to have one folder specific for each week.

So in /media or whichever folder you mount the external drives. There will be Week1, Week2, Week3 or Week4 folders.

Of course backup can be done manually, but it will be awesome and if it could be done automatically.

Bash script and crontab will come to the rescue.

For Bash script to check which folder to use, this piece of snippet code below.

If there are four folders on /media and each external drive is mounted to an specific folder.

Once the drive is inserted, Linux OS will automatically activate the mount drive and the mounted folder.

Here’s the piece of snippet code below:

======================

#!/bin/sh

# Path to the mounted folders
W1=”/media/Week1″
W2=”/media/Week2″
W3=”/media/Week3″
W4=”/media/Week4″

# Check if folder exists
if [ -d “$W1” ]
then
 PathBackup=”$W1″

elif [ -d “$W2” ]
then
PathBackup=”$W2″

elif [ -d “$W3” ]
then
PathBackup=”$W3″

elif [ -d “$W4” ]
then
PathBackup=”$W4″

fi

# you can do a simple cp or copy command
# or any command that you want to run
# command below uses rysnc and pipe to gzip and date as filename
# the date used is the date that the script runs
rsync  -arv /home/backup/store/ | gzip > ‘$PathBackup’ `date ‘+%m-%d-%Y’`.zip

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And you can configure crontab to run the script at a specified date and time.

Type crontab -e and configure the settings as desired.