The environment variable setting technique under Linux, do not need to/etc/profile but create a new shell file in the/ETC/PROFILE.D directory to set

Difference:

1, two files are set environment variable file,/etc/profile is a permanent environment variable, is a global variable,/etc/profile.d/set all users to take effect, is also a permanent variable, is a global variable.

2,/etc/profile.d/than/etc/profile good maintenance, do not want to what variables directly delete/etc/profile.d/under the corresponding shell script can, not like/etc/profile need to change this file.

3. It is important to note that/etc/profile and/ETC/PROFILE.D are also login-level variables that are triggered when the user logs back into the shell. So the effect is consistent.

4, usually set the login level of variables, re-login shell can, or source/etc/profile.

Originally:

Setting environment variables is usually written in/etc/profile, now it seems really low, if hundreds of applications, then find and modify to get is a different thing! So the problem is that the upgrade is done by creating a shell file in the/etc/profile.d/directory to apply the command, and then removing the required variables directly from the shell file.

Right now:

The same way, just create a new shell in the/etc/profile.d/directory, such as new Java:

vi/etc/profile.d/java.sh

Export Java_home=/data/service/java

Principle:

Whether in Linux or Mac, can be implemented in this way, analysis/etc/profile This file you will find a shell, this is the key:

if  then   for  in/ETC/PROFILE.D/*. sh; do    if [-R $i]; then      . $i Fi-Done  unset ifi

Summarize:

Do not use the same low way before, change the plan, so operation is the King!!!

The environment variable setting technique under Linux, do not need to/etc/profile but create a new shell file in the/ETC/PROFILE.D directory to set