solc-abi.sh

# install solidity on Mac
brew update
brew upgrade
brew tap ethereum/ethereum
brew install solidity
brew linkapps solidity

# compile solidity contract
cat << EOF | solc - --abi
pragma solidity ^0.4.21;

contract CallMeChallenge {
    bool public isComplete = false;

    function callme() public {
        isComplete = true;
    }
}
EOF


##############  prints ###########################################

======= <stdin>:CallMeChallenge =======
Contract JSON ABI
[{"constant":false,"inputs":[],"name":"callme","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"isComplete","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"}]