1. User & Login Information

1.1 who

Shows users currently logged in.

who
sc       tty1         2025-11-05 08:11

1.2 w

Displays who is logged in and their activity.

w

09:34:20 up  1:23,  1 user,  load average: 1,97, 2,00, 1,93
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCP...

1. nfsstat

nfsstat is a command-line utility that displays statistical info about the Network File System (NFS) and Remote Procedure Call (RPC) calls. It is a part of the nfs-utils package.

To display information about the number of RPC and NFS calls received and rejected by the server :

nfsst...

This trick can be useful in case we are the only user using the same machine. Being asked each time for a sudo password can be really grueling.

1. Open the sudoers file :

   sudo visudo

2. add this line :

   sc ALL=(ALL) NOPASSWD: ALL

   This will allow user "sc" to run all commands without a sud...

Suppose we are asked to install a Debian based flavor on an old laptop or PC but we are unsure about the type of disk that is used. One solution could be the use of a bootable live usb to check performance and gather system specifications prior to installation. This post will walk us through helpf...

7. Working with strings

7.1 Case insensitive matching

The i or I as a flag for the substitution command implies case-insensitive substitution. Here, the pattern is lowercase and the s command will substitute to upper case ignoring case.

sed  -n 's/victor hugo/VICTOR HUGO/pi' books.log

Th...