How to build a conditional assignment in bash?

Question

I\'m looking a way to build conditional assignments in bash:

In Java it looks like this:

int variable= (condition) ? 1 : 0;

Answer 1

Big ups to @Demosthenex and especially @Dennis Williamson for the shortest and easiest solution I've seen. Leave it to bash to require a bunch of parentheses for a simple ternary assignment. Ahh, the 60s! And to put it all together in an example...

echo $BASHRULES;             # not defined
                             # no output
: ${BASHRULES:="SCHOOL"}     # assign the variable
echo $BASHRULES              # check it
SCHOOL                       # correct answer
: ${BASHRULES="FOREVER?"}    # notice the slightly different syntax for the conditional assignment
echo $BASHRULES              # let's see what happened!
SCHOOL                       # unchanged! (it was already defined)

I wrote that a long time ago.. these days I'd probably get more excited over a solution like...

PLATFORM=iphonesimulator
OTHERSDK=iphone && [[ $PLATFORM=~os ]]      \
                &&     OTHERSDK+=simulator  \
                ||     OTHERSDK+=os

$OTHERSDK ⇥ iphoneos