gnupg: Agent GETINFO
2.6.16 Return information about the process
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This is a multipurpose function to return a variety of information.
GETINFO WHAT
The value of WHAT specifies the kind of information returned:
'version'
Return the version of the program.
'pid'
Return the process id of the process.
'socket_name'
Return the name of the socket used to connect the agent.
'ssh_socket_name'
Return the name of the socket used for SSH connections. If SSH
support has not been enabled the error 'GPG_ERR_NO_DATA' will be
returned.