Some notes mainly...

..............................................................................

# Make a play list file.pls
find . -type f -iname '*.mp3' | grep -v pls | sort > '00-playlist.pls'

# Count lines in file foo
wc -l my-text.txt

# Found at http://forums.gentoo.org/viewtopic-t-296892.html
mount -t tmpfs -o size=128m none /preload > /dev/null 2>&1
cd /preload

# add user to group (I think, double check later..)
gpasswd -a <username> audio
.........
/etc/group
.........
usermod -G <group>,<group> <user>

# something else
normalize -m *.wav
cdrecord dev=1,0,0 -eject speed=4 -pad -audio *.wav

#########

mkdir foo{1,2,3}bar
or
mkdir foo1bar foo2bar foo3bar

###########

mount -t iso9660 -o ro /dev/cdrom /cdrom
1) mkisofs -r -o /location/of/iso.iso /directory
# for linux, not windows: mkisofs -r -R -J -l -L -o /location/of/iso.iso /directory
2) same as 1) except "/directory" is " /dev/cdrom"
   for above 3 commands use full path names. (or not)

#############

# Ripping audio cd:
cdda2wav -D 1,0,0 -B /Music/directory2save/to

############

for song in music/*; do f="${song##*/}"; echo ${f/-*/} ; done | sort | uniq

########

dd if=/path/to/iso of=/dev/<USB Drive>

#####################

wget -r <--recursive> -c <--continue> -q <--quiet> --random-wait -F <--force-html> http://path/to/website

########

env-update
source /etc/profile

# while emerging something, run this in another terminal:
tail -f /var/log/emerge-fetch.log
###
equery -q list -i gentoo-sources | awk '{ print "=" $1 }' | xargs emerge --noreplace

#################
mplayer -zoom -fs file.avi
mplayer dvd:// /mnt/cdrom
fbi
wv
###########

# below commands I learned from a friend
emerge --sync (eix-sync)
emerge --update --deep --newuse --keep-going --ask world # or for short "-uDNa --keep-going"
revdep-rebuild
emerge --depclean -pv
emerge --depclean
revdep-rebuild
eclean-dist -dp
eclean-dist -d
####################

# found in gentoo websites installation handbook. Note, don't assume this is up to date.
# www.gentoo.org may change something and anything on their website..
mount -t proc none /mnt/gentoo/proc
mount --rbind /dev /mnt/gentoo/dev
chroot /mnt/gentoo /bin/bash
env-update
source /etc/profile
export PS1="(chroot) $PS1"

exit; cd; umount -l /mnt/gentoo/dev{/shm,/pts,}
umount -l /mnt/gentoo{/boot,/proc,} ; reboot

#########################

# use equery to locate interesting files:
equery files alsa-lib | less

#########################

EOF.