sync -- flush all pending disk output


sync [fileId]


If fileId is not specified, or if it is and this system does not support the fsync system call, this issues a sync system call to flush all pending disk output. If fileId is specified and the system does support the fsync system call, it issues an fsync on the file corresponding to the specified Tcl fileId to force all pending output to that file out to the disk.

If fileId is specified, the file must be writable. A flush is issued against the fileId before the sync.

The infox have_fsync command can be used to determine if sync fileId will do a sync or an fsync.