To generate keypair :
gpg --gen-key
Listing:
To list all public keys
gpg --list-keys
gpg -k
To List private keys -
gpg --list-secret-keys
gpg -K
Encrypt/Decrypt:
The option -a is for armor (Base64 output)
To encrypt gpg -a -e -r <recipient> [file]
To decrypt gpg -a -d [file]
Sign:
To create a signed version of the file gpg [-a] -s <file>
To create a separate signature gpg --detach-sign -a <file>
Verify and decrypt are the same thing. Or use the specific verify option
gpg --verify file.asc file
Export:
To export a public key: gpg --export -a <id/email>
To export a secret key: gpg --export-secret-keys -a -o <outfile> <id/email>
Import:
To import a key: gpg --import <key.gpg>