indexOf

let text = "docker run -d -p 8080:8080 -p 8081:8081 -p 8081:8081 -p 8081:8081 -P 8082 -P 8082 -e key1=value1 -e key2=value23 -e key3 value3"
let array1 = findStringIndex(text, " -p ");
let array2 = findStringIndex(text, " -P ");
let array3 = findStringIndex(text, " -e ");
function findStringIndex(text1, text2) {
    let array = [];
    let index = text1.indexOf(text2);
    while (index !== -1) {
        array.push(index);
        index = text1.indexOf(text2, index + 1);
    }
    return array;
}