linux上的常用的系统自带命令

  wikipedia 发现的分类，发现还有好多没用过。。

Unix command-line interface programs and shell builtins
File system	cat cd chmod chown chgrp cksum cmp cp dd du df file fsck fuser ln ls mkdir mount mv pax pwd rm rmdir size split tee touch type umask
Processes	at bg chroot cron fg kill killall nice pgrep pidof pkill ps pstree time top
User environment	clear env exit finger history id logname mesg passwd su sudo uptime talk tput uname w wall who whoami write
Text processing	awk banner basename comm csplit cut diff dirname ed ex fmt fold head iconv join less more nl paste sed sort spell strings tail tr uniq vi wc xargs
Shell builtins	alias echo expr printf sleep test true and false unset wait yes
Networking	dig host ifconfig inetd netcat netstat nslookup ping rdate rlogin route ssh traceroute
Searching	find grep locate whatis whereis
Documentation	apropos help man
Miscellaneous	bc dc cal date lp lpr
List of Unix utilities