Qjob: A job queuing script

Most systems administrators are familiar with using the cron facility or the at command to schedule jobs. Sometimes an attempt is made to schedule jobs so they don't conflict with one another. For example, it may be necessary to limit the number of resource-intensive jobs running at the same time to avoid overloading the system. Or you may need to prevent jobs from simultaneously accessing a shared resource. This can be challenging, especially if commands must be run frequently and the time they take to complete is significant and variable.