Tries to get the UNIX process identifier from @credentials. This
method is only available on UNIX platforms.
This operation can fail if #GCredentials is not supported on the
OS or if the native credentials type does not contain information
about the UNIX process ID (for example this is the case for
%G_CREDENTIALS_TYPE_APPLE_XUCRED).
Tries to get the UNIX process identifier from @credentials. This method is only available on UNIX platforms.
This operation can fail if #GCredentials is not supported on the OS or if the native credentials type does not contain information about the UNIX process ID (for example this is the case for %G_CREDENTIALS_TYPE_APPLE_XUCRED).