The /proc interface

The configuration of the running Linux kernel can be examined through the /proc filesystem.

/proc entries are simply 'hooks' into the kernel, being presented as a filesystem.
Previously, ugly system calls or other hacks were necessary to see the running configuration.

 $ ls -la /proc/version
 -r--r--r--    1 root  root       0 Apr 23 09:44 /proc/version
 $ cat /proc/version
 Linux version 2.2.21 (bri@ifokr.org) #1 Fri Feb 28 11:45:28 EST 2003

 $ ls -la /proc/ide/ide1/hdc/model
 -r--r--r--    1 root  root       0 Apr 23 09:46 ide/ide1/hdc/model
 $ cat /proc/ide/ide1/hdc/model
 TOSHIBA DVD-ROM SD-C2302