Teamprise 3.0 introduced named connection profiles as an alternative to fully specifying login credentials to TFS or relying on automatically cached information when using the command-line client. While profiles offer a level of flexibility and convenience not available in older releases of Teamprise, the use of these profiles is optional. However, the behavior of the CLC when profiles are not used has changed slightly since release 2.2.
When the connection profiles feature was added, the credential caching behavior of the CLC was changed: credentials are no longer saved to the workspace cache by default.
Teamprise 2.2 and older automatically cached connection credentials (username, password, domain) inside the local workspace cache. When the older CLC was given a path in the workspace cache as an argument, or when the current working directory was in the workspace cache, these credentials would be automatically used. The login option could be used at any time to override these cached credentials.
In Teamprise 3.0, the role of the workspace cache remains largely the same, but credentials are not automatically written in the cache unless the TP_AUTO_SAVE_CREDENTIALS environment variable is set. This behavioral change allows the Teamprise CLC to operate in environments that require no credentials are ever cached on disk. Setting the TP_AUTO_SAVE_CREDENTIALS environment variable to any value (like "1", "on", "enabled", etc.) will enable automatic credential caching, and the the Teamprise CLC will behave similarly to older versions. This environment variable only affects whether credentials are written to the workspace cache, not whether they are read and used if present.
Frequent users of the CLC who desire automatic credentials caching are encouraged to configure their environment through login scripts or another way so the environment variable is automatically set. See Defining an Environment Variable for instructions.
Teamprise 3.0 will also prompt for missing credentials upon connecting to a Team Foundation Server, which makes operating without credential caching easier. The login option may still be used with almost any command to override the credentials retrieved from the workspace cache (or a named connection profile if one was specified).
It's important to note that the TP_AUTO_SAVE_CREDENTIALS environment variable does not affect the credentials stored or read from a connection profile in any way. A profile is always explicitly configured using the CLC's profile command or with the Teamprise Explorer or Teamprise Plug-in for Eclipse programs (profiles are shared between all Teamprise clients). The CLC will never automatically update the credentials in a connection profile, and profile credentials will be used when the profile is specified regardless of the value of the TP_AUTO_SAVE_CREDENTIALS environment variable.
You may choose to omit some or all credentials from a connection profile and the CLC will prompt for them when needed.