Declare a host variable

Declare Informix® ESQL/C host variables for database columns of type CLOB or BLOB as a fixed binary host variable with the ifx_lo_t structure (called an ifx_lo_t data type) as follows: 
EXEC SQL include locator;
⋮

EXEC SQL BEGIN DECLARE SECTION;
   fixed binary 'clob' ifx_lo_t clob_loptr;
   fixed binary 'blob' ifx_lo_t blob_loptr;
EXEC SQL END DECLARE SECTION;
⋮

EXEC SQL select blobcol into :blob_loptr from tab1;
Tip: For more information about the fixed binary Informix® ESQL/C data type, see Access a fixed-length opaque type.

To access smart large objects, you must include the locator.h header file in your Informix® ESQL/C program. This header file contains definitions of data structures and constants that your program needs to work with smart large objects.