List of commands available to the Android shell

ls /system/bin

Many of these are actually symbolic links to Android toolbox (which is a cut-down Busybox.)

LE_dut
adb
am
app_process
applypatch
bcm4334.hcd
bcm4334_murata.hcd
bcm4334_semco.hcd
bcm_dut
bintvoutservice
bluetoothd
bmgr
bootanimation
brcm_patchram_plus
brcm_poke_helper
bu
bugreport
cat
chmod
chown
cmp
csview
dalvikvm
date
dbus-daemon
dd
ddexe
debuggerd
dexopt
df
dhcpcd
diagexe
dmesg
dnsmasq
drmserver
dttexe
dumpstate
dumpsys
e2fsck
fsck.exfat
fsck_msdos
gbias
getevent
getprop
gps.cer
gpsd
gzip
hciattach
hd
hostapd
icd
id
ifconfig
iftop
ime
immvibed
input
insmod
installd
insthk
ioctl
ionice
ip
ip6tables
iptables
keystore
kiesexe
kill
linker
ln
log
logcat
logwrapper
lpmkey
ls
lsmod
lsof
macloader
make_ext4fs
mcDriverDaemon
mediaserver
mfgloader
mkdir
mkfs.exfat
mksh
monkey
mount
mtpd
mv
nandread
ndc
netcfg - similar sort of info you'd expect from ifconfig; I see lo, sit0, ip6tnl0, rmnet0/1/2, plus wlan0 if wifi is enabled when rmnet0 reverts to 0.0.0.0.
netd
netstat - current connections and their states (LISTEN, SYN_SENT, etc).

newfs_msdos
notified_event
notify
npsmobex
omx_tests
pand
ping
playlpm
pm - package manager, type: pm list packages
pppd
printenv
ps
racoon
reboot
renice
rild
rm
rmdir
rmmod
route
run-as
samsungani
samsungpowersoundplay
schedtest
schedtop
scranton_RD
screencap
screenshot
sdcard
sdptool
sendevent
sensorservice
service
servicemanager
setconsole
setprop
setup_fs
sh
simg2img
sleep
smd
smdexe
start
stop
surfaceflinger
svc
sync
system_server
tc
toolbox
top
touch
umount
uptime
vdc
vmstat
vold
watchprops
wipe
wlandutservice
wpa_supplicant