SQL write CLOB to IFS file

ifs_write_clob.sql

-- This example are using the IFS_WRITE and IFS_APPEND 
-- to produce a IFS files based on CLOB data in UTF-8
-----------------------------------------------------
create or replace procedure qusrsys.ifs_write_clob(name varchar(256), buf clob  ccsid 1208 ) 
external action 
modifies sql data

specific IFS_WRTCLB
set option output=*print, commit=*none, dbgview = *source
begin

    declare remlen int;
    declare startpos int;
    declare writelen int;
        
    if buf is not null then 
        set remlen = length(buf);
        set startpos  = 1;
        while remlen > 0 do 
            set writelen = min(32000 ,remlen);
            if startpos = 1 then
                call qusrsys.ifs_write (name, substring ( buf , startpos , writelen));
            else
                call qusrsys.ifs_append (name, substring ( buf , startpos , writelen));
            end if; 
            set startpos = startpos + writelen;
            set remlen = remlen - writelen;  
        end while;
    end if;
end;    

-- Usecase
-- Write huge clob:
call qusrsys.ifs_write_clob('/tmp/test.txt'  , repeat (clob('Hello ') , 10000));    

-- Write JSON
call qusrsys.ifs_write_clob('/tmp/test.json'  , 
    json_array((
        select 
            json_object (
                'customerNumber' : trim(CUSNUM),
                'name' : trim(LSTNAM)
            )
        from qiws.qcustcdt
    ))
);