Find out installed EPEL RPM packages

yum list installed | grep @epel

Global Subversion Settings for CA Certificates

How to avoid

Error validating server certificate for 'https://host.example.com:443':

when doing

svn co https://svn.example.com/project/trun

in a system-wide manner:

wget -O /etc/ssl/certs/your_cer.pem https://example.com/your_cert.pem
mkdir /etc/subversion
cat <<EOF > /etc/subversion/servers
[global]
ssl-authority-files = /etc/ssl/certs/your_cer.pem
EOF

Change Oracle User Password

$ su - oracle
$ sqlplus / as sysdba
SQL> alter user USER identified by "PASSWORD";

VirtualBox 4 USB support in Linux

Download VirtualBox Oracle VM VirtualBox Extension Pack and install it by VirtualBox → File → Preferences... → Extensions → Add package.

Then grant vboxusers groups access to the USB device filesystem:

$ grep 108 /etc/group
vboxusers:x:108:
$ vim /etc/fstab
usbfs  /proc/bus/usb  usbfs  auto,busgid=108,busmode=0775,devgid=108,devmode=0664  0  0

Password protected GRUB Legacy

Add password into the main GRUB section to password protect the interactive operations (i.e. editing menu entries and entering the command-line interface). Optionally add lock into a menu entry to prevent it from executing if no valid password is provided by the user.

$ grub-md5-crypt 
Password: 
Retype password: 
$1$K0Kh10$OmQNQOthH8jppDFQ5TYx5/

$ chmod 600 /boot/grub/menu.lst
$ vim /boot/grub/menu.lst
default 0
...
password --md5sum $1$K0Kh10$OmQNQOthH8jppDFQ5TYx5/

title Linux
kernel ...

title OpenBSD
lock
kernel ...

Create a svn tag from trunk

svn mkdir http://svn.example.com/project/tags -m "release directory"
svn copy http://svn.example.com/project/trunk \
         http://svn.example.com/project/tags/1.0 -m "release 1.0"

Nicer Oracle Date Output

Oracle date output including full year, month, day, hours, minutes and seconds:

SQL> alter session set nls_date_format = 'yyyy-mm-dd hh24:mi:ss';
SQL> alter session set nls_timestamp_format = 'yyyy-mm-dd hh24:mi:ss';
SQL> select foo_date from bar_table where rownum <= 1;

FOO_DATE
-------------------
2012-01-01 01:02:03