Each Tamino API for C function except tac_init() returns an
integer value.
Upon success, this value is the predefined constant
TAC_SUCCESS, which is defined as 0 in the header file
TaminoAPI4C.h.
If a function call fails, an error code is returned. A negative value
indicates that the API already detected an error without communicating with
Tamino. An error code between 100 and 999 indicates a communication problem,
see HTTP
Status Codes
for more details. An error code greater than 999 indicates a processing
problem in the Tamino XML Server; more details can
be obtained by calling the function tac_get_messagetext().
