Show version of the kernel

cat /proc/version

This command lists all known encodings

iconv -l

Install / upgrade a deb package from cdrom/dvd

apt-cdrom install package_name

Change user and group ownership of a file

chown user:group file

Show memory use

$ cat /proc/meminfo

List all packages installed on the system

yum list

Force delete a file

rm -f file

View in real time what is added to a file. -f stands for Follow

tail -f /var/log/messages

Show network adpters and statistics

cat /proc/net/dev

Creates a new from the given input file by assuming it is encoded in fromEncoding and converting it to toEncoding.

iconv -f fromEncoding -t toEncoding inputFile > outputFile