Solution for user is not in sudoers file when sudo is used

In Linux, this error is often reported when a common user uses sudo, for example:
[Oracle @ DBA2 fd] $ sudo ps-ef | grep dbw
[Sudo] password for oracle:
Oracle is not in the sudoers file. This incident will be reported.
[Oracle @ DBA2 fd] $
The error is reported because the user oracle is not in The sudo configuration file, and the oracle user has no permission to use sudo;
 
Solution:
You can modify the attribute of the/ete/sudoer file as root by using the root user, and add oracle ALL under the root ALL line (similar to the root line)
[Root @ DBA2 etc] # chmod u + w sudoers
[Root @ DBA2 etc] # vi sudoers
Add oracle ALL = (ALL) ALL
 
Change the sudoer attribute back to the original value:
[Root @ DBA2 etc] # chmod u-w sudoers
[Root @ DBA2 etc] # ll sudoers
-R -- r ----- 1 root 3402 Sep 4 10:40 sudoers
 
Try the sudo command again. You can use it;
[Oracle @ DBA2 ~] $ Sudo ps-ef | grep dbw
[Sudo] password for oracle:
Oracle 3140 1 0? 00:00:06 ora_dbw0_orcl2
Oracle 19299 17065 0 00:00:00 pts/2 grep dbw

Recommended reading:

Use and enable the root account with Ubuntu sudo and su commands

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Temporary root permission for sudo Configuration

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