[ Thanks to Digger for this link.
]
“One of the least-talked-about tools in a UNIX sysadmin’s
toolkit is lsof. Lsof lists information about files opened by
processes. But that’s really an understatement.“Most people forget that, in UNIX, (almost) everything is a
file. The OS makes hardware available to applications by way of
files in /dev. Kernel, system, memory, device etc. information in
made available inside files in /proc…”