gistfile1.cls

public class Account {
}

gistfile2.cls

Account anAccount = new Account();
account.Name = 'Test';

gistfile3.cls

public class checkRecursive {
    private static boolean run = true;
    
    public static boolean runOnce() {
        if(run) {
            run = false;
            return true;
        } else {
            return run;
        }
    }
}

gistfile4.trigger

trigger updateTrigger on anyObject(after update) {
    if(checkRecursive.runOnce()) {
        // write your code here            
    }
}

gistfile5.trigger

trigger updateTrigger on anyObject(after update) {
    static Boolean run = true;
    
    if(run) {
        run = false;
        // write your code here
    }
}