Header files for ESQL/C typedefs

C header files (.h) are required to define C structures for complex data types used in a C-Extension.

To compile C-Extensions using data types such as DECIMAL, DATETIME/INTERVAL or BYTE/TEXT, you need IBM® Informix® ESQL/C data type structure definitions such as dec_t, dtime_t, intrvl_t, as well as macros such as TU_ENCODE().

These definitions are not required, if you use standard C types such as short, int or char[].

The definition of the ESQL/C structures like dec_t are provided in individual header files, under the $FGLDIR/include/f2c directory: fglDecimal.h, fglDatetime, fglLocator.h.

In order to include these data type header files, simply include the fglExt.h header file:
#include "f2c/fglExt.h"

The other header files are then included automatically.