There are several environment variables that affect the Qpid library in qpid client programs.
They are similar to configuration options for the qpidd broker.
Loadable Modules
By default a qpid client loads modules from a default directory, the exact location depends on your system.
qpidd --help will show you the default directory for broker modules. If the broker directory is <path>/daemon, then the client directory is <path>/client.
The following environment variables modify how modules are loaded:
QPID_MODULE_DIR: Load modules in this directory instead of the default directory.
QPID_LOAD_MODULE: Load this additional module.
QPID_NO_MODULE: Don't load modules from the default directory.
Logging
The client recognizes the same logging options as the broker as environment variables. qpidd --help will show you the logging options available.