The issue:

I'm attempting to create a LiveUSB distro and I need to identify what drive/device the LiveUSB is running on. Since it's a LiveUSB the boot device can change depending on what computer its plugged into sometimes it's sda1, or sdb1, sdd1, ect.

I noticed some LiveCD's make this easy since the root directory is usually linked to /media, but I'm modifying tinycore as a base which doesn't do this. Fortunately it will be the only device mounted automatically. I know there are a few command line commands that can list attached devices like mount but how do I grab the output in a usable string for use in a script. The device LABEL will always be the same predefined string if that helps in anyway.

Summary: What I want is to identify the boot device by script rather than relying on user input. How do I capture the deviceid in a string so I can do:

mnt/$deviceid/games


Thanks in advance for your help!

What I commonly state is that anything you can type in a command line you can put into a bash script.

This process works better if you post what you do know and do have for output now so that people can help you better.

sounds like you want UUIDs.

Maybe (untested on live system)

1 members found this post helpful.

Both mount and df return the device mounted on /

Thanks, I'll try this soon and let you know if it works.

Thanks for the help, I think I need 1 more small tweak.

That function returns rootfs which is the 1st word in the 1st line of what the mount command returns :

rootfs on / type rootfs (blahblahblah)

but not what I want. I guess I didnt explain well when I mentioned there would only be 1 device mounted, there is a ton of listings for type squashfs mounts.

Mount -t vfat will return the line I want:

/dev/sdb1 on /mnt/sdb1 type vfat (moreinfothananyonecouldeverwant...)

Keep in mind sdb1 can change, and thats what Im trying to capture

I don't understand your string parsing magic to adapt:

root=$(mount -t vfat| awk '$3 == "/" {print $1}')
device=$(echo $root | sed 's/[0-9]*//g')

It seems to be returning null right now.

Any more ideas?

wrong post...

A tweak is to ensure that the first field starts with a / character
When awk exits before the pipe is finished then a SIGPIPE is sent to mount which will terminate. This can be faster on a big systems with many mounts:

1 members found this post helpful.

Well lets call this solved... I eventually went with

bootdev=$(mount -t vfat | cut -c6-9)

Unfortunately shortly after that I learned you can't create Symbolic Links on Fat32 filesystems, making the whole point of this moot.

Thanks for the help anyway guys.