Error Messages and Recovery Procedures (Out-of-Date)

Commands produce messages, either to signal their actions, or whenever they fail to execute properly to indicate the reason of the failure. The syntax of the message if the following C-Facility, Error message text
where C is a one letter severity code, Facility is the name of the command or of a subroutine called by the command, and ``Error message text'' is a short explanation.

Messages can be divided into four categories according to the severity code

• S (Success) or I (Information) messages indicate normal successful operations.
• W (Warning) messages indicate that the operation completed, but that the result may not be significant.
• E (Error) messages indicate a failure to complete the command. The result of the command is undefined, but these messages are usually signaled when checking the input parameters before executing the command. In particular, the Input and Output files are never affected by these errors.
• F (Fatal) messages indicate severe errors which happened while a command is executing. They may have left the input or output files in an incoherent state. These errors are typically hardware errors.