Normally, when using
sudo, you don't have access to aliases that have been defined for your user. These aliases are useful of course, so it's nice to make them available in a sudo context.
To do so, simply add this line to your
alias sudo="sudo " - note the space after the second sudo
How does this work?
When running a command, only the first word is checked against your aliases. So
myalias by itself will work, but running
sudo myalias means that only
sudo is checked against your aliases - not the second word
The trick of aliasing sudo to itself (plus a space!) works because "[when] the last character of the alias value is a space or tab character, then the next command word following the alias is also checked for alias expansion." - from the bash manual
sudo myalias will check both words against your aliases.