Getting Kernel Information
==========================

procfs
------

Linux offers various interfaces to expose internal kernel information. One of them is procfs (Process Filesystem).

Linux shows information through files under /proc. Every file under the directory is an interface for accessing to particular information.

The following command is an example to get CPU information through procfs.::

  $ cat /proc/cpuinfo

If you wish to get memory information, please type following command::

  $ cat /proc/meminfo

For accessing information for a specific process, we should look into a directory */proc/PID*.

For instance, we can see the generic status of a process whose PID is 1.::

  $ sudo cat /proc/1/status

We can see the virtual address mapping of a process whose PID is 1 by the following command.::

  $ sudo cat /proc/1/maps

By the way, we can do the same thing through the standard read operation::

  $ python3
  >>> fp = open('/proc/cpuinfo', 'r')
  >>> content = fp.read()
  >>> fp.close()
  >>> print(content)


sysfs
-----

The concept of sysfs is similar to procfs. Mainly sysfs is used for showing information about kernel sub-systems, hardware and device drivers.

It depends on situations, but procfs may offer much more interesting information.