Sometimes it's better to set aside the cynic within and go with the flow. Perhaps you are giving a guy money to feed a drug habbit but perhaps you are, in some cases like you mentioned, helping out someone who really needs a bit of charity to get through their day. When you walk away, you get to choose which scenario you want to believe, when I give a guy something I choose to believe it will be used for good purposes. Which is why I do it only with people where that scenario is plausible.
In the end, an act of charity benefits the recipient but it also benefits the giver. Always yielding to the cynic within robs you of that. So sometimes I tell him to shut up and I choose to give something.
I never give money...though I will give stuff - or even come back with a sandwich or baked potato.
If they’re hungry, fine. If they only want money, they’re probably up to no good.