sudoers grant

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

For example:

less command

The navigation keys in less command are similar to Vim editor.

Forward Search

Backward Search

For viewing large log files

Useful other command

File paging
You can open multiple files by passing the file names as arguments:

virtualbox: mount shared esterno su linux

You have to specify the path and folder to share with the service name on virtualBox

for the mount you can use this command:

sudo mount -t vboxsf nome_servizio /shared_name

you need on your linux OS one folder (mkdir shared_name)

for example if the service name is “stage” and the folder name on the system is shared you can use this command:

sudo mount -t vboxsf stage /shared

for the unmount you can use:

sudo umount -t vboxsf stage /shared


#archive the file without compression.
tar file_name

(1) create tar cfv tar c=create, f=file (on the disk and not on the tape),v=verbose (show file list).

ex: tar cfv archive.tar *.txt create the file’s archive of all txt files in the same path.

ex: tar -cvf /destination_path/filename.tar /path to put in the tar file

(2) tvf to show the content of the archive: tar tfv archive.tar

(3) xfv archive file extraction: tar xfv archive.tar