HP 3000 Manuals HP 3000 Manuals
Closing a File The following sections describe modifications to the behavior of the FCLOSE intrinsic beginning with MPE/iX Release 4.5. Closing shared files Prior to Release 4.5, if a conflict occurred between the disposition specifications of multiple FCLOSE intrinsic calls on a shared file, the disposition specification that had the lower positive-integer value always took precedence when the file was finally closed. Beginning with Release 4.5, this behavior is modified if one of the processes sharing the file invokes the POSIX.1/iX library function unlink() to purge the file from the directory. Upon successful completion of the unlink() call, the file is moved from the permanent file domain to the new file domain. When this occurs, the behavior of the FCLOSE intrinsic on the shared file may change. Care must be taken only in an environment where processes using the FCLOSE intrinsic share files with processes calling the unlink() C library function available through the MPE/iX Developer's Kit. Closing directory files Directory files exist only in the permanent file domain. Attempting to perform an FCLOSE specifying a domain disposition of anything other than "no change" or "close as permanent" on an open directory file results in an FCLOSE error. The directory file remains open.