I have a function that selects a random object form an array. I have wrapped the internal bash function RANDOM, and implemented my function like that:
function rand() { echo $[ $RANDOM % $2 + $1 ]; }
function rand_obj() { objs=($@); index=$(rand 0 $#); echo ${objs[$index]} ; }
It works just fine, but I would love to learn a way of implementing it without the intermediate array objs. Any ideas? Thanks in advance
Does something like this
rand_obj() {
shift $(( $(rand 1 $#) - 1 )); echo "$1"
}
do what you want?
The above has problems with arguments that end with newlines.
Command Substitution always removes trailing newlines.
To handle that scenario you'd need to stick a dummy character/etc. at the end and remove it at use time. Something like this:
rand_obj() {
shift $(( $(rand 1 $#) - 1 )); echo "$1x"
}
elem=$(rand_obj ... ... ... ... ...)
elem=${elem%x}
there are too many ways. here is almost oneliner, but assume you have no space in your strings, and you never touched IFS:
echo ${ARRAY[@]} | tr ' ' '\n' | shuf -n1
shift $(( $(rand 1 $#) - 1 )); echo "$1"?