Содержание
- 2. Chapter Goals Describe the purpose of files, file systems, and directories Distinguish between text and binary
- 3. Chapter Goals Compare and contrast sequential and direct file access Discuss the issues related to file
- 4. File Systems File A named collection of related data File system The logical view that an
- 5. Text and Binary Files Text file A file in which the bytes of data are organized
- 6. Text and Binary Files The terms text file and binary file are somewhat misleading They seem
- 7. File Types Most files, whether they are in text or binary format, contain a specific type
- 8. File Types File names are often separated, usually by a period, into two parts Main name
- 9. File Operations Create a file Delete a file Open a file Close a file Read data
- 10. File Access Sequential access Information in the file is processed in order, and read and write
- 11. File Access Figure 11.2 Sequential file access
- 12. File Access Direct access Files are conceptually divided into numbered logical records and each logical record
- 13. File Access Figure 11.3 Direct file access
- 14. File Protection In multiuser systems, file protection is of primary importance We don’t want one user
- 15. File Protection A file’s protection settings in the Unix operating system is divided into three categories
- 16. Directory Trees A directory of files can be contained within another directory The directory containing another
- 17. Directory Trees Figure 11.4 A Windows directory tree
- 18. Directory Trees At any point in time, you can be thought of as working in a
- 19. A Unix Directory Tree
- 20. Path Names Path A text designation of the location of a file or subdirectory in a
- 21. Path Names Examples of absolute path C:\Program Files\MS Office\WinWord.exe C:\My Documents\letters\applications\vaTech.doc C:\Windows\System\QuickTime Suppose the current working
- 22. Disk Scheduling File systems must be accessed in an efficient manner As a computer deals with
- 23. Disk Scheduling 11-23
- 24. Disk Scheduling First-Come, First-Served Requests are serviced in the order they arrive, without regard to the
- 25. Disk Scheduling SCAN Disk Scheduling works like an elevator An elevator is designed to visit floors
- 26. How To Transfer Files FTP Clients FileZilla is one of the best
- 27. Other Types Of File Transfers & Systems Secure FTP (SSH, SFTP, FTPS) Network File System (NFS)
- 28. BitTorrent BitTorrent greatly reduces the load on seeders, because clients generally download the file from each
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