Shulou(Shulou.com)06/01 Report--

Today, the editor will share with you the relevant knowledge of what the misunderstanding of Linux using su command is, the content is detailed and the logic is clear. I believe most people still know too much about this knowledge, so share this article for your reference. I hope you can get something after reading this article.

When many friends use the su instruction, they often use the following form:

Example: switch from general account moonlit to root account

$su

So is there anything wrong with this?

Let's take a look at the data comparison before and after account switching.

[moonlit@host ~] $

Execute the following statement before switching to view the variables in the environment that contain moonlit:

$env | grep 'moonlit'

The screen displays as follows:

USER=moonlitMAIL=/var/spool/mail/moonlitPATH=/usr/java/jdk1.7.0_60/bin:/usr/lib64/qt-3.3/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/moonlit/binPWD=/home/moonlitHOME=/home/moonlitLOGNAME=moonlit

Perform the switchover:

$su

Password:

After entering the password, the screen is converted to:

[root@host ~] #

Enter # pwd to view the current path

/ home/moonlit

Hey, why is it still under the home directory of your moonlit account?

Then enter # env | grep 'moonlit'

Screen output:

USER=moonlitPATH=/usr/java/jdk1.7.0_60/bin:/usr/lib64/qt-3.3/bin:/usr/local/bin:/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin:/home/moonlit/binMAIL=/var/spool/mail/moonlitPWD=/home/moonlitLOGNAME=moonlit

Did you see that? The environment hasn't changed.

Because there is no change to the root environment, it may cause a lot of root instruction errors or invalid oh.

To fully convert users to root, you can use the following instructions:

[moonlit@host ~] $su-

Change to [root@host ~] # after typing the root password

# pwd:

/ root

Then # env | grep 'moonlit':

There is no such thing.

Env: at this time the screen will display all the variables, more, not enumerated one by one, you can see the current home directory, PATH, MAIL and so on have all been replaced with root variables.

Finally, you can issue # exit to exit the current root user and return to moonlit.

These are all the contents of the article "what is the misunderstanding of Linux using the su command". Thank you for reading! I believe you will gain a lot after reading this article. The editor will update different knowledge for you every day. If you want to learn more knowledge, please pay attention to the industry information channel.

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