/proc filesystem

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proc Filesystem

Certain filesystems like the one mounted at /proc are called pseudo filesystems because they have no permanent presence anywhere on disk.

The /proc filesystem contains virtual files (files that exist only in memory) that permit viewing constantly varying kernel data. This filesystem contains files and directories that mimic kernel structures and configuration information. It doesn't contain real files but runtime system information (e.g. system memory, devices mounted, hardware configuration, etc). Some important files in /proc are:

/proc/cpuinfo
/proc/interrupts
/proc/meminfo
/proc/mounts
/proc/partitions
/proc/version

/proc has subdirectories as well, including:

/proc/
/proc/sys

The first example shows there is a directory for every process running on the system which contains vital information about it. The second example shows a virtual directory that contains a lot of information about the entire system, in particular its hardware and configuration. The /proc filesystem is very useful because the information it reports is gathered only as needed and never needs storage on disk.