C-ISAM and Unix permissions

I have a problem with access permissions on C-ISAM files: I have a C-ISAM database that belongs to user u1, group g1, with following permissions: -rw-r--r-- u1 g1 file.dat -rw-r--r-- u1 g1 file.idx The directory where these files resid has following permissions: drwxr-sr-x u1 g1 directory My program opens the database for read-only operations: { ... fd = isopen("directory/file", ISINPUT+ISMANULOCK); ... } When user u1 launches this program, there isn't any problem. But when user u2 from group g2 launches the program, the isopen() fails with error 13 (Permission denied). I don't understand this, since my intent is only a read, and these files are accessible for reading by everyone. Obviously, I could give write access to everybody, but don't you think it could be dangerous ? I need help ! What can I do for granting read-only access to everybody on my C-ISAM files ? -- \\\\\\\\ //// (o o) (o o) +----------oOO--(_)--OOo--------------------oOO--(_)--OOo----------+ | mailto:O.Miakinen@frcl.bull.fr Phone: 33 (1) 30 80 70 42 | | http://www-ism.bull.com/ism Fax: 33 (1) 30 80 79 18 | +-------------(_)-(_)--------------------------(_)-(_)-------------+