Can I connect my generator directly to an outlet that is used by my electrical dryer. I was told that as long as I shut the main it would be safe. Then I would be able to use certain appliances as long as I do not exceed the output of the generator.

It is illegal to hook up without a transfer switch.

If you forget to shut off main and power comes back on , it could cause a fire or kill someone.

I have seen some hooked up with a knife switch with one side of knife for generator and the other side for the main. Do not know if this is legal, but is safer then going into dryer outlet.

Chuck

NO. You cannot do this. It is illegal, unsafe and will not work properly.

Get a transfer switch or main breaker interlock with the proper inlet box.

Theoretically you "could"
However as others have stated it is very illegal, dangerous, and just generally unsafe. If the main were left on, you could cause a fire, electrocute a lineman, or burn up the generator when power is restored. To be legal (and safe) you would need to wire a transfer switch or an interlock kit. (You can internet search these).

If you think about it, when it's 3 AM and dark. And you're trying to hook up the generator, you could always forget to shut the main off. Also, someone else could come along and turn the main on not knowing any better, so it's best to do it right.

First, I agree with the need for a transfer switch...
But just for fun, if your house is like mine there are three or four of your neighbors connected to the utility transformer also. So if you "left the main on" and tried to start the generator, it would see the load of the other houses and never start!