Currently defined functions:
[, [[, ash, basename, blkid, cat, chgrp, chmod, chown, chroot, clear, cut, dd, df, dirname, dmesg,
dnsdomainname, du, echo, egrep, eject, env, expr, false, fdisk, fgrep, free, ftpget, ftpput, grep, gunzip,
head, hostname, hwclock, ifconfig, ifdown, ifup, init, ip, ipaddr, iplink, iproute, iprule, iptunnel, kill,
killall, klogd, ln, loadfont, login, logread, ls, lspci, lsusb, mkdir, mkswap, more, mount, mv, ntpd, passwd,
pidof, ping, pivot_root, ps, pwd, readlink, renice, rev, rm, route, sed, setfont, sh, sleep, sort, stat,
swapoff, swapon, switch_root, sync, syslogd, tail, tee, test, tftp, timeout, touch, tr, true, udhcpc, umount,
uname, usleep, wc, zcat