Busybox is a command that provides many of the common linux commands.
Push busybox into your phone's internel memory, then get to use the linux commands, just like "find", "grep" etc.
adb push busybox /data/local/busybox adb shell $cd /data/local $chmod 777 busybox $./busybox BusyBox v1.8.1 (2007-11-14 10:11:37 EST) multi-call binary Copyright (C) 1998-2006 Erik Andersen, Rob Landley, and others. Licensed under GPLv2. See source distribution for full notice. Usage: busybox [function] [arguments]... or: [function] [arguments]... BusyBox is a multi-call binary that combines many common Unix utilities into a single executable. Most people will create a link to busybox for each function they wish to use and BusyBox will act like whatever it was invoked as! Currently defined functions: [, [[, addgroup, adduser, adjtimex, ar, arp, arping, ash, awk, basename, bunzip2, bzcat, bzip2, cal, cat, catv, chattr, chgrp, chmod, chown, chpasswd, chpst, chroot, chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond, crontab, cryptpw, cut, date, dc, dd, deallocvt, delgroup, deluser, df, dhcprelay, diff, dirname, dmesg, dnsd, dos2unix, du, dumpkmap, dumpleases, echo, ed, egrep, eject, env, envdir, envuidgid, ether-wake, expand, expr, fakeidentd, false, fbset, fdflush, fdformat, fdisk, fgrep, find, fold, free, freeramdisk, fsck, fsck.minix, ftpget, ftpput, fuser, getopt, getty, grep, gunzip, gzip, halt, hdparm, head, hexdump, hostid, hostname, httpd, hwclock, id, ifconfig, ifdown, ifup, inetd, init, insmod, install, ip, ipaddr, ipcalc, ipcrm, ipcs, iplink, iproute, iprule, iptunnel, kbd_mode, kill, killall, killall5, klogd, last, length, less, linux32, linux64, linuxrc, ln, loadfont, loadkmap, logger, login, logname, logread, losetup, ls, lsattr, lsmod, lzmacat, makedevs, md5sum, mdev, mesg, microcom, mkdir, mkfifo, mkfs.minix, mknod, mkswap, mktemp, modprobe, more, mount, mountpoint, mt, mv, nameif, nc, netstat, nice, nmeter, nohup, nslookup, od, openvt, passwd, patch, pgrep, pidof, ping, ping6, pipe_progress, pivot_root, pkill, poweroff, printenv, printf, ps, pscan, pwd, raidautorun, rdate, readlink, readprofile, realpath, reboot, renice, reset, resize, rm, rmdir, rmmod, route, rpm, rpm2cpio, run-parts, runlevel, runsv, runsvdir, rx, sed, seq, setarch, setconsole, setkeycodes, setlogcons, setsid, setuidgid, sh, sha1sum, slattach, sleep, softlimit, sort, split, start-stop-daemon, stat, strings, stty, su, sulogin, sum, sv, svlogd, swapoff, swapon, switch_root, sync, sysctl, syslogd, tail, tar, taskset, tcpsvd, tee, telnet, telnetd, test, tftp, time, top, touch, tr, traceroute, true, tty, ttysize, udhcpc, udhcpd, udpsvd, umount, uname, uncompress, unexpand, uniq, unix2dos, unlzma, unzip, uptime, usleep, uudecode, uuencode, vconfig, vi, vlock, watch, watchdog, wc, wget, which, who, whoami, xargs, yes, zcat, zcip