DbFiles NOTE: this document describes OpenIsis 0.9/0.9.1. For updated information please refer to Malete files order of opening database files checking options try to read an options file .opt or .OPT if found, merge options with those passed, and use the successful case for extensions else, if the last path component contains an uppercase ascii and no lowercase ascii, use uppercase extensions Options may select to open only index or only data. For both index and data, either traditional or new files are used during normal operation, with new files preferred. However, both sets may be open during copying. if no read/write mode is explicitly selected, readonly is used if a TXT or MST file exists and is readonly. (By index file permissions in index-only mode). checking data if TXT exists, use it, done if traditional MST/XRF exist, and they are writable or writing was not explicitly selected, use them as is, done create TXT and copy any available readonly data If for a TXT no valid PTR exists, create one. checking index if OXI exits, use it, done if traditional index files exist, open readonly else, OR if writing is wanted create OXI for writing, copy old index