How get uuid of a device/partition in linux progra

Question

I am very much new to Linux programming.

My questions are:

• Is there any way to read the UUID of a device or partition in Linux programmatically?
• Is there any C/C++ API for user-space applications?

I found some commands sudo vol_id --uuid /dev/sda1, sudo blkid and ls -l /dev/disk/by-uuid/. But all of them are commands which need to run in a terminal. But I need to achieve this from a C/C++ program.

Can some one help me with this problem. (FYI: I need to read UUID of the root filesystem ("/") where Linux has been installed.)

Thank you in advance.

Answer 1

The general approach would be:

• find out what device your / is on by parsing /etc/mtab for example
• go through the /dev/disks/by-uuid directory (using opendir/readdir/closedir) and find which one points to that device.

See the readlink function for getting the target of a symbolic link. You'll find plenty of code examples for parsing text files on this site or with your favorite search engine.

Answer 2

Since blkid already does it, you could also just see how it works and pilfer the solution, if you abide by util-linux's license (GPLv2).