Linux

21.5    The /proc and /sys Directories

The /proc and /sys directories are mounted to the file system during system startup. They are used to make information about the kernel, running processes, loaded modules, and many other parameters visible in a transparent way.

Internally, the /proc and /sys directories are implemented as virtual file systems. Thus, they do not contain real files and therefore do not take up any space on the hard disk. This also applies to the seemingly very large /proc/kcore file, which maps the memory.

Most of the /proc and /sys files are in text format.

To read the files, you may have to use cat instead of less, because some less versions cannot handle virtual files.

The /proc directory provides a lot of internal kernel ...