which file system?

is there a linux command that lets me read a cd,cdrw,cdr,dvd-ram, etc. to determine what is the file system type? not a problem with hard drive. its in the fstab, but I have cd-rws and dvd-rams with data, yet I cannot read it because I do not know the file type. -- John Sowden American Sentry Systems. Inc. 1221 Andersen Drive San Rafael, CA 94901 U.L. Listed Central Station Alarm Service Serving the San Francisco Bay Area Since 1967 mail@americansentry.net http://www.americansentry.net