env命令

linux系统中的环境变量是很多的，就算是一些常用的环境变量我们也不一定能记得全名。env命令可以显示当前操作系统所有的环境变量，下面的示例代码是Ubuntu系统的。

示例

dai@ubuntu:~$ env
USER=dai
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
SSH_AUTH_SOCK=/run/user/1000/keyring-6YCIFa/ssh
DEFAULTS_PATH=/usr/share/gconf/ubuntu.default.path
XDG_CONFIG_DIRS=/etc/xdg/xdg-ubuntu:/usr/share/upstart/xdg:/etc/xdg
PATH=/usr/local/arm/arm-2009q3/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
PWD=/home/dai
HOME=/home/dai
UPSTART_EVENTS=started starting
LOGNAME=dai
QT4_IM_MODULE=xim
XDG_DATA_DIRS=/usr/share/ubuntu:/usr/share/gnome:/usr/local/share/:/usr/share/
DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-PERqBL8H1o
LESSOPEN=| /usr/bin/lesspipe %s
INSTANCE=Unity
UPSTART_JOB=unity-settings-daemon
TEXTDOMAIN=im-config
XDG_RUNTIME_DIR=/run/user/1000
DISPLAY=:0
XDG_CURRENT_DESKTOP=Unity
GTK_IM_MODULE=ibus
LESSCLOSE=/usr/bin/lesspipe %s %s
TEXTDOMAINDIR=/usr/share/locale/
COLORTERM=gnome-terminal
XAUTHORITY=/home/dai/.Xauthority
dai@ubuntu:~$