sudoers grant

For grant sudoers to user in redhat, centos, oralce linux, edit the file /etc/sudoers and append
username ALL=(ALL) ALL
under
root ALL=(ALL) ALL

For example:

## Next comes the main part: which users can run what software on
## which machines (the sudoers file can be shared between multiple
## systems).
## Syntax:
##
##     user    MACHINE=COMMANDS
##
## The COMMANDS section may have other options added to it.
##
## Allow root to run any commands anywhere

root    ALL=(ALL)     ALL
oracle    ALL=(ALL)     ALL