keychain:tldr:f9e81
The keychain
command is used to manage SSH and GPG agents. An agent is a program that holds private keys and passwords in memory and can authenticate on behalf of the user. The keychain
command is used to start and manage these agents, ensuring that they are running and accessible to other processes.
In the given command, --agents "${gpg,ssh}"
is passed as an argument to the keychain
command. This argument specifies the agents that need to be started and managed by keychain
.
The agents specified are ${gpg,ssh}
. The ${}
syntax is used for variable expansion/ substitution. In this case, it means that the keychain
command will start and manage both the GPG and SSH agents.
So, by running keychain --agents "${gpg,ssh}"
, the keychain
command will start and manage the GPG and SSH agents, making them accessible to other processes that require their services.