$ tail -5 ~/.bashrc
if [ -f /home/db2inst3/sqllib/db2profile ]; then
    . /home/db2inst3/sqllib/db2profile
fi
$ ls -l /home/db2inst3/sqllib/db2profile
-rwxr-xr-x  1 db2inst3 db2iadm1 6625 Apr 24 12:26 /home/db2inst3/sqllib/db2profile
$ /home/db2inst3/sqllib/db2profile
$ perl
use strict;
use warnings;
use DBI;
use DBD::DB2;
DBI->connect('DBI:DB2:viper', 'db2inst3', '');
__END__
DBI connect('viper','db2inst3',...) failed: Total Environment allocation failure!  Did you set up your DB2 client environment? at - line 5