tp: Return Codes

The transport control program tp collects all return codes that arise when a tp command is executed. A combined return code is calculated from the various return codes. tp produces these as a result at the end of the command. During an import, all return codes for individual import steps are handled, for example. If a special return code does not arise, the combined return code at the end is the maximum of the individual return codes that arise. In addition to the value of the return code, tp also provides a short description of it. The command explainrc is used to display this short description.

Normally, all return codes that arise originate from individual transport steps. Since these individual return codes can only have the values 0, 4, 6, 8, 12, 13, 14 or 16, the combined return code also has one of these values. However, if a general error occurs, a single return code over 200 is normally created. For example, this could arise if tp cannot establish a connection to the database. The maximum return code for all single transport steps is posted in a separate message before the combined returned code is announced. In this case, the combined return code is always the return code from the general error message.