gistfile1.txt

$ ssh-keygen -f some_key -C 'this key is awesome'
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in some_key.
Your public key has been saved in some_key.pub.
The key fingerprint is:
9c:28:d3:69:81:a7:37:8b:1f:21:48:0d:05:72:55:40 this key is awesome
The key's randomart image is:
+--[ RSA 2048]----+
|. +=Eo.          |
| o o .           |
|  . o o          |
| . . + = .       |
|  . = O S        |
|     B +         |
|    . o          |
|     . .         |
|      .          |
+-----------------+
$ cat some_key.pub 
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAsXJEavNgOmAeZ/ZaKU5Pbdv3Z722Xu7iZSqvySiTBSavFPuYUmPpioKpoPlgwyzwKxPvknSbh1T+pUIJ9LfZpn3Xs8hIDGwt9KnkZ0OQw/9ohW2BNSAxIAN6RUtVVJjTn0W/Ag0Ymv60ypa6h3vbrf7giKc7NC6OzF15JrelN27hI1gNYAsw1IL7nOPsSku4NtJWxST80Ea0FtuC8RQZfrHaowPDIuf3KFDLYxuMvF4FlZHB9J2S7j2O2sglAfCu9WT50+tdQQ9Ygxlbdb6j/iVBYP6M0H42rpKZraL6feUMN1McfvqVKKJNHFDF6MR4LUR0rGHobDtfA+yC6pj2dQ== this key is awesome