Informix_unl_import is a project mainly written in Perl, it's free.
Import Informix UNL dumps into SQLite or other DBI database
Import directory full of UML dumps from Informix into SQLite
http://blog.rot13.org/2011/02/migration_of_informix_unl_dump_files_using_sql.html
Usage:
./informix_unl_import.pl demodbThis will begin import from demodb directory into /dev/shm/demodb.sqlite and display progress.