I have lots of information about configuring ODBC and PHP5, and I am confused as to which, if not both, odbc.ini files to configure. I keep getting this error when running a simple php program from CLI.

Warning: odbc_connect(): SQL error: [unixODBC][Driver Manager]Data source name n
ot found, and no default driver specified, SQL state IM002 in SQLConnect in
/hom
e/ics/scratch/test.php on line 7

where line 7 is the odbc_connect call in my test.php file.

I am more interested in figuring out the relationship of all this stuff so I can understand how to solve it than getting "the problem solved". If anyone has any ideas, I would appreciate it.

BTW: php is installed fine, and a command line program that calls phpinfo(); works just fine. Informix is installed correctly. Its native tools and Perl's DBI can talk to one of several Informix DBs I work with. It's just getting the relationship between PHP and Informix that's confusing me, and I am keeping Apache out of this.