How can I find out what these files or processes do (linux)

When I go onto a *nix system and look as ps -A or -e or top I get a large number of processes that are running. For example.

init
migration/0
ksoftirqd/0
events/0
khelper
kacpid
kblockd/0
khubd
pdflush
pdflush
kswapd0
aio/0
kseriod
scsi_eh_0
kjournald
udevd
kauditd
kjournald
kjournald
kjournald
kjournald
kjournald
klogd
portmap
rpc.idmapd
sshd
xinetd
gpm
xfs
salinfod
dbus-daemon-1
cups-config-dae
hald
kjournald
agetty
minilogd
kjournald
screen
bash
sshd
bash

Now some i know what their purpose is, but many i cannot even seem to track down on Google, or i just get oblique开发者_如何学JAVA references to, such as a post from a forum in 1999 complaining about the process.

Other than tracking them down one by one is there somewhere i can go to get a better explanation?

N.B. I am not asking anyone to tell me directly what they are but pointers to where i can get the understanding myself.

The stuff in square brackets are kernel threads. For the others, get the full name (try adding www to the command line) and hit Google, or look at /proc/<pid>/exe and use your package manager to figure out which package the executable comes from.

Some processes might have an associated manpage (the d at the end of most processes stand for daemon, you can also try the name without the d)

man processname