How access other files in a bootable linux usb flashdrive?
 

I made a linux bootable usb flash drive. When I browse that usb flash drive in windows, it has a boot folder and inside it is the grub folder. Then I put a file in the flash drive in the same directory level as the boot folder. How can I access that file when I boot the usb flash drive in the other computer? When I am in the linux shell already?

Regards,
archieval

What other computer?
Another machine with a Linux distribution installed? Access to do what? Read? Edit? Do you mean a file in the /boot directory or the / directory? If you have a file in /boot named file you would just do: cat /boot/file to read it. To edit you would open a text editor and navigate to it. You don't indicate which distribution of Linux you are using and there are numerous text editors and they vary with the distribution. Might be helpful if you indicated what you are trying to do.

machine 1 = windows
machine 2 = no OS

I can access the content of my bootable linux usb flash drive in machine 1. Then I placed a text file in the flash drive.

Now in order to boot machine 2, I will insert the bootable linux usb in that so that it will boot in linux. Now how can I access the file inside the flash drive in machine 2 when the flash drive itself was used to boot it up?

It depends on the distribution you're using as to where the USB drive gets mounted, if at all.

You can, once in Linux:

grep sd /etc/mtab

...which will tell you which removable drives are attached and where they're mounted. Your USB drive will probably be in that list.

If your USB drive isn't in that list, it should be safe to mount it anywhere.

After that, the file would be in the root of the directory where the drive is mounted.