Concurrent programming has become a common means to harness the potential performance of multi-core processors. System V (SysV) message queues and semaphores have been used since the mid 1970s to implement inter-process concurrency, but they are difficult to use, and bindings exist for few programming languages. This paper introduces ipcmd, a high-level command-line interface to SysV message queues and semaphores. ipcmd provides an easy-to-use interface for synchronizing concurrent processes to allow application developers to efficiently prototype, debug, and test the use of SysV semaphores and message queues in applications. Easy-to-understand applications of semaphores are illustrated using simple shell scripts. Copyright © 2013 John Wiley & Sons, Ltd.