GNU/Linux Commands for Beginners: which and whatis

commandline session

$which ls
/bin/ls
$which firefox
/usr/bin/firefox
$which grep
/bin/grep
$which whatis
/usr/bin/whatis
$whatis which
which (1)            - locate a command
$whatis whatis
whatis (1)           - display manual page descriptions
$whatis linux
linux: nothing appropriate.
$whatis kcore
kcore: nothing appropriate.
$whatis mysql
mysql: nothing appropriate.
$whatis locate
locate (1)           - find files by name

following video tutorial content may not be accurate

[youtube https://www.youtube.com/watch?v=rLSRFvL-DVE?rel=0&w=560&h=315]

GNU/Linux command : Changing Passwords

commandline session

$sudo -
[sudo] password for jeffrin:
sudo: -: command not found
$
$su -
Password:
root>passwd -e jeffrin
passwd: password expiry information changed.
root>exit
logout
$login jeffrin
login: Cannot possibly work without effective root
$sudo login jeffrin
[sudo] password for jeffrin:
sudo: Account or password is expired, reset your password and try again
Changing password for jeffrin.
(current) UNIX password:
Enter new UNIX password:
Retype new UNIX password:
Password:
Last login: Sat Nov  2 22:01:20 IST 2013 on pts/0
Linux debian 3.11-1-amd64 #1 SMP Debian 3.11.5-1 (2013-10-17) x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
No mail.
$exit
logout
$sudo -s
[sudo] password for jeffrin:
Sorry, try again.
[sudo] password for jeffrin:
sudo: 1 incorrect password attempt
$su -
Password:
root>passwd jeffrin
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
root>

following video tutorial content may not be accurate

[youtube https://www.youtube.com/watch?v=xiA2FSUeXQA?rel=0&w=560&h=315]

Git server and SSH Debian HOWTO

the following content may not be accurate and detailed

Server

1. apt-get install git
2. apt-get install  git-daemon-sysvinit
3. mkdir  -p /home/user/project.git
4. cd /home/user/project.git
5. git init
6. git config --global user.name "Your Name"
7. git config --global user.email "you@example.com"
8. git commit -a
9. touch .git/git-daemon-export-ok
10. git config --bool core.bare true
11. edit /etc/init.d/git-daemon file and change to
"GIT_DAEMON_BASE_PATH=${GIT_DAEMON_BASE_PATH:-/home/user}"
12. service git-daemon restart

Client

1. git clone ssh://user@server/home/user/project.git