Under UN*X? No. The big function would be making queries to either the FS or the kernel, depending on the OS.

Under MacOS? No problem. See Mac::MoreFiles. A function already exists to do that. (MacOS supports mandatoy file locking.)

Under AFS (AtheOS)? Node watching is supported and encouraged (cool stuff).

Under NFS? Too much chance for race conditions- no way.

Under VMS? I don't know.

Under Win32? I don't care.

If you come a across a situation where you need to know if a file is currently being used without some form of IPC, you're in bad shape- this is indicative of a poor design.

AgentM Systems nor Nasca Enterprises nor Bone::Easy nor Macperl is responsible for the comments made by AgentM. Remember, you can build any logical system with NOR.