bk = FILE_BACKUP(#channel)
bk = FILE_BACKUP(‘filename’)
This function reads the backup date from the file header and returns it into the variable bk. The parameter can either be a channel number for an open channel, or it can be the filename (in quotes) of a closed file. If the returned value is negative, it is a normal QDOS error code. If the value returned is positive, it can be converted to a string be calling DATE$(bk). In normal use, a files backup date is never set by QDOS, however, users who have WinBack or a similar backup utility program will see proper backup dates if the file has been backed up.
1000 bk = FILE_BACKUP('flp1_boot') 1010 IF bk <> 0 THEN 1020 PRINT "Flp1_boot was last backed up on " & DATE$(bk) 1030 ELSE 1040 PRINT "Flp1_boot doesn't appear to have been backed up yet." 1050 END IF