linux的环境变量怎么设置?

在/etc/profile下的什么位置下加入
JAVA_HOME=...
export JAVA_HOME
呀!
我加了,可是每次重开shell后都要source profile才有效!
到底怎么设置呀!
有没有一次搞定的办法呀?

怎不在 ~/.bash_profile 設置?
我的 samples
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs
JAVA_HOME=/usr/local/jre1.5.0_04
export JAVA_HOME
JAVA_BIN=$JAVA_HOME/bin
export JAVA_BIN
CLASSPATH=$CLASSPATH:$JAVA_HOME:$JAVA_HOME/lib
PATH=$JAVA_BIN:$PATH:$HOME/bin:/usr/local/Acrobat5/bin
export PATH CLASSPATH
unset USERNAME
export NNTPSERVER="freenews.netfront.net"

不太可能，因为在系统启动的时候，/etc/profile是要被系统执行的。

When  bash is invoked as an interactive login shell, or as a non-inter-
       active shell with the --login option, it first reads and executes  com-
       mands  from  the file /etc/profile, if that file exists.  After reading
       that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile,
       in  that order, and reads and executes commands from the first one that
       exists and is readable.  The --noprofile option may be  used  when  the
       shell is started to inhibit this behavior.

不错，/etc/profile是首先被执行的，检查你的拼写是否有误！