
$ echo 'obase=2;1234'  bc
April 11, 2012, 11:20 p.m.
—
Janos
Explanation
bc is an arbitrary precision calculator language.
obase defines the conversion base for output numbers, in this example 2 (binary)
; is a statement separator in bc
1234 is the decimal number to convert
 By piping the command to
bc we get 1234 in binary format
