The previous column looked at using /proc to examine. There’s a lot of other information available there as well.
proc is fundamentally a myth: It’s a virtual
filesystem, and when you ask to read a file, it talks to other bits
of the kernel, retrieves the information, and hands it back as though it were
a file. This makes it great both for communication between different
parts of the system and prodding around at.
Tip of the Trade: Learn more about proc, how it works and how to get the most out of it.
You are probably already familiar with cpuinfo and
meminfo, which tell you about the machine’s CPU and memory
respectively. You can also get uptime and version information from
uptime and version. This, in fact, is where the uname command
gets its information.
The net/ directory provides the raw info for various networking
information commands, such as route. The text-system communication of
/proc goes both ways: As well as accessing information, you can
change it by editing the various files. Look at /proc/sys/net/ipv4/ to
see some values that you can change if you want.
partitions gives information on the partitions — this can be more useful than using df and quicker than fdisk. filesystems lists the filesystems that the kernel can deal with, and marks them with nodev
if they’re either virtual or networked. This is handy if you’re dealing with
filesystems on remote hardware, or a Mystery Hard Drive, to check what
filesystems you are able to read.
Spend some time having a poke through /proc with the man page to
find out what else is there.