1. Guide to Parallel Operating Systems with Windows 7 and Linux Chapter 7 Files and File Attributes

2. Guide to Parallel Operating Systems with Windows 7 and Linux Objectives Describe the contents of files and identify the application that created a particular file Describe the use of file attributes Find files based on their name or content 2

3. Guide to Parallel Operating Systems with Windows 7 and Linux Contents of Files File: –Discrete set of information OS stores program modules in file systems Save documents under filenames for future use Section learning goals: –Recognizing the contents of files –Recognizing actions a given OS takes to open a file 3

4. Guide to Parallel Operating Systems with Windows 7 and Linux Contents of Files in Windows 7 Filename: name plus “.” plus extension –Example: default.htm Two types of extensions: –Short extension is three characters (older convention) –Long extension exceeds three characters Extensions indicate type of data stored in a file Windows 7 appends extension to filename prefix 4

5. Guide to Parallel Operating Systems with Windows 7 and Linux Viewing File Extensions in Windows 7 Windows tracks the extensions your PC uses Viewing registered file extensions: –Click Start-> Control Panel -> click Default Programs, and then click “Associate a file type or protocol with a program” –Example: MS WordPad documents have an extension of.rtf Administrative rights required to modify extensions 5

6. Guide to Parallel Operating Systems with Windows 7 and Linux6 Figure 7-1 File extensions in Windows 7 Courtesy Course Technology/Cengage Learning

7. Guide to Parallel Operating Systems with Windows 7 and Linux Viewing File Extensions in Windows 7 (continued) File associations –Which icon appears for a file in Windows Explorer –Which commands appear in a file’s shortcut menu Which application opens if a user double-clicks a file Icon appearance in Windows Explorer –Eliminated feature: Displaying different icons for files based on file type 7

8. Guide to Parallel Operating Systems with Windows 7 and Linux Commands in a File’s Shortcut Menu Right-click a file icon to view a shortcut menu Choices appearing on all file shortcut menus: –Create a shortcut –Delete a file –Rename a file –View file properties Some shortcut menu items are object specific: –Example: Open and Print are used in MS WordPad Bold items identify default response to double-click 8

9. Guide to Parallel Operating Systems with Windows 7 and Linux9 Figure 7-2 Context menu Courtesy Course Technology/Cengage Learning

10. Guide to Parallel Operating Systems with Windows 7 and Linux Opening Applications Default response to double-clicking a file icon: –Windows 7 opens file in associated application Example: response to double-clicking Homework.rtf –OS opens the file In WordPad because: WordPad is associated with.rtf files Default action in Folder Options is defined as Open Changing the default program: – Right-click the file icon, then click Open with – From the dialog box that appears: Browse for program to use with the selected file type 10

11. Guide to Parallel Operating Systems with Windows 7 and Linux11 Figure 7-3 Open with dialog box showing default program for.rtf files Courtesy Course Technology/Cengage Learning

12. Guide to Parallel Operating Systems with Windows 7 and Linux Applications in Windows 7 Table 7-1: –Lists common file extensions for business applications Table 7-2: –Identifies the programming language for a particular source file Table 7-3: –Lists some of the many Internet file extensions and formats you may encounter Table 7-4: –Lists the files you are most likely to encounter 12

13. Guide to Parallel Operating Systems with Windows 7 and Linux13 Table 7-1 Common business applications and their file extensions

14. Guide to Parallel Operating Systems with Windows 7 and Linux14 Table 7-2 Common programming source files

15. Guide to Parallel Operating Systems with Windows 7 and Linux15 Table 7-3 Common Internet files

16. Guide to Parallel Operating Systems with Windows 7 and Linux16 Table 7-4 Common Windows 7 files

17. Guide to Parallel Operating Systems with Windows 7 and Linux Viewing the Contents of Text Files TYPE command: –Displays contents of a text file line by line –Example: TYPE Pgm1Data.txt MORE command: –Displays text data files one screen at a time –Example: TYPE Pgm1Data.txt | MORE –Syntax: MORE [/E [/C] [/P] [/S] [/Tn] [þn]] < drive:][path]filename MORE < Pgm1Data.txt : –Displays contents of the Pgm1Data.txt file 17

18. Guide to Parallel Operating Systems with Windows 7 and Linux Contents of Files in Fedora 13 Fedora 13 and Windows 7 file similarities: –Filenames may have extensions –OS associations open files in usable formats Extension not required to open a file from the CLI Inode: –Used to store applications files and directory attributes –Does not contain file/directory name or actual data Filename does not require an extension When a file is created: –It is assigned both a name and an inode number 18

19. Guide to Parallel Operating Systems with Windows 7 and Linux19 Table 7-5 Extensions for Fedora 13 compressed and archived files Contents of Files in Fedora 13 (continued)

20. Guide to Parallel Operating Systems with Windows 7 and Linux20 Table 7-6 Extensions for Fedora 13 multimedia files Contents of Files in Fedora 13 (continued)

21. Guide to Parallel Operating Systems with Windows 7 and Linux21 Table 7-7 Extensions for Fedora 13 system configuration and installation packaging files Contents of Files in Fedora 13 (continued)

22. Guide to Parallel Operating Systems with Windows 7 and Linux Contents of Files in Fedora 13 (continued) 22 Table 7-8 Extensions for Fedora 13 programming files

23. Guide to Parallel Operating Systems with Windows 7 and Linux Contents of Files in Fedora 13 (continued) ls command with the –l option –Determines file type –ls –l /dev | more: Lists files in the devices folder Syntax for the file command: –file[filename(s)] file Pgm1Data : –Examines a plain text file named Pgm1Data 23

24. Guide to Parallel Operating Systems with Windows 7 and Linux24 Figure 7-4 Listing Fedora 13 file types Courtesy Course Technology/Cengage Learning

25. Guide to Parallel Operating Systems with Windows 7 and Linux25 Table 7-10 Fedora 13 file command types Contents of Files in Fedora 13 (continued)

26. Guide to Parallel Operating Systems with Windows 7 and Linux Viewing Files in Fedora 13 Use cat command to view or concatenate files: –Example: cat –bsT Pgm1Data more command syntax: more [-dlfpcsu] [file...] Some more command options: -num : specifies screen size in lines (an integer value) -d : displays “[Press ‘h’ for instructions]” -f : causes more to count logical lines (not folded) To display the contents of myfile: cat myfile more –dfs red_canoe 26

27. Guide to Parallel Operating Systems with Windows 7 and Linux Using File Attributes File attributes: –Labels describing and regulating files –Associated with every file in Windows 7 –Maintained by components in Windows 7 Windows 7 handles file attributes most of the time Users can also manipulate file attributes: –Learning the technique will prove useful 27

28. Guide to Parallel Operating Systems with Windows 7 and Linux Using File Attributes in the Windows 7 CLI File attributes have binary values of 1 (on) or 0 (off) The four DOS file attributes are: –Read-only: allows file viewing, but not modification –Archive: set to on when file is created or modified –System: marks a file as a system file (a warning) –Hidden: hides a file from other commands 28

29. Guide to Parallel Operating Systems with Windows 7 and Linux Viewing DOS File Attributes View attributes and access methods with ATTRIB ATTRIB syntax: ATTRIB [drive:][path][filename][/S] –[drive:][path][filename] : specifies file(s) to process –/S : matches files in current folders and subfolders –Similar to DIR command Wildcards must be used in ATTRIB command: –Without wildcards, no files will match 29

30. Guide to Parallel Operating Systems with Windows 7 and Linux Viewing DOS File Attributes (continued) 30 Figure 7-8 Viewing DOS file attributes Courtesy Course Technology/Cengage Learning

31. Guide to Parallel Operating Systems with Windows 7 and Linux Setting DOS File Attributes ATTRIB: shows or changes DOS file attributes –Syntax : ATTRIB [+R | -R] [+A | -A] [+S | -S] [+H | -H] [drive:][path][filename] [/S [/D]] + : sets an attribute - : clears an attribute R : read-only file attribute A : archive file attribute S : system file attribute H : hidden file attribute Example: ATTRIB +H Secret –Hides the directory named Secret 31

32. Guide to Parallel Operating Systems with Windows 7 and Linux Using the DIR Command with File Attributes Use DIR to view filenames and specified attributes Syntax: DIR [drive:][path][filename] [/A[[:]attributes]] [drive:][path][filename]: specifies drive, directory, files /A : displays files with specified attributes Attributes : “D”,“R”, “H”, “A”, “S”, “-” (logical not prefix) 32

33. Guide to Parallel Operating Systems with Windows 7 and Linux Using the XCOPY Command with File Attributes XCOPY syntax: XCOPY source [destination] [/A | /M] [/H] [/R] [/K] Attribute options: /A : copies only files with the archive attribute set Used for differential backup as archive bit is not reset /M : copies files with archive bit set; turns off archive bit Used in incremental backup as archive bit is reset /H : copies hidden and system files /R : overwrites read-only files /K: copies attributes; read-only is typically reset 33

34. Guide to Parallel Operating Systems with Windows 7 and Linux Using the XCOPY Command with File Attributes 34 Figure 7-11 XCOPY command used with file attributes Courtesy Course Technology/Cengage Learning

35. Guide to Parallel Operating Systems with Windows 7 and Linux Using File Attributes in the Windows 7 GUI Additional attributes: Index, Compression, Encryption –Applies to folders or files residing on an NTFS volume Index: –File/Folder indexed by Indexing Service when bit is set –Windows Indexing Service organizes files for search –Index created by Windows 7 can be queried Compression: –File or folder is compressed when bit is set Encryption: –File or folder encrypted when bit is set 35

36. Guide to Parallel Operating Systems with Windows 7 and Linux36 Figure 7-12 Windows 7 advanced file attributes Courtesy Course Technology/Cengage Learning

37. Guide to Parallel Operating Systems with Windows 7 and Linux Using Compression in Windows 7 Compressing files: –Decreases file size –Reduces space that files use on your drives Compressing folders: –Decreases space used by files stored in a folder Disadvantage of compression: –Potential loss of performance 37

38. Guide to Parallel Operating Systems with Windows 7 and Linux Using Encryption in Windows 7 Encryption: restricts file viewing Users who may view (decrypt) encrypted files: –Individual who encrypted the file –Administrator (account has a global key) Encrypting File System (EFS) performs encryption: –Installed automatically on Windows 7 38

39. Guide to Parallel Operating Systems with Windows 7 and Linux Using File Attributes in Fedora 13 lsattr : used to view attributes on extended file system Some attributes: a (“no Access time”): last access time not updated A (“append only”) Set for file: only allows append operations Set for directory: files may only be added to directory lsattr command syntax: lsattr [options] [file(s)] Some lsattr command options: -d : lists directories like other files -v : lists the file’s version/generation number 39

40. Guide to Parallel Operating Systems with Windows 7 and Linux Using the ls Command to Find Hidden Files ls command: –Views filenames with specific file type attributes –Syntax: ls [OPTION]... [FILE]... –Some options: -a, --all : does not hide entries starting with “.” -l : uses a long listing format -p, --file-type : appends an indicator of /, =, @, or | to entries to indicate types of files 40

41. Guide to Parallel Operating Systems with Windows 7 and Linux41 Figure 7-14 Using the Fedora 13 ls command to show hidden files and file types Courtesy Course Technology/Cengage Learning

42. Guide to Parallel Operating Systems with Windows 7 and Linux Using Compression in Fedora 13 Compressing files: –Decreases their size –Reduces amount of space they use on drives Folder compression: –Decreases amount of space used by all file gzip : –Commonly used GNU compression utility –By default: deletes ASCII file it compresses –Command: basis for gunzip and zcat 42

43. Guide to Parallel Operating Systems with Windows 7 and Linux Using Compression in Fedora 13 (continued) zcat utility: –Identical to using the gunzip –c command –Keeps the original filename and stamp Syntax: gzip [ -acdfhlLnNrtvV19 ] [-S suffix] [ filename... ] gunzip [ -acfhlLnNrtvV ] [-S suffix] [ filename... ] zcat [ -fhLV ] [ filename... ] 43

44. Guide to Parallel Operating Systems with Windows 7 and Linux Using Compression in Fedora 13 (continued) Some switches for gzip, gunzip, and zcat : -a –ascii : converts end-of-line characters -c --stdout --to-stdout : writes output to standard output -L –license : displays the license and quits Syntax to compress file: –gzip myfile Syntax to decompress a file: –gzip –d myfile 44

45. Guide to Parallel Operating Systems with Windows 7 and Linux Using Compression in Fedora 13 (continued) gunzip myfile: decompresses a file zcat utility: –Decompresses files created by gzip, zip zcat myfile: decompresses a file tar command: –Works in conjunction with gzip –Packages multiple files into one file –Syntax: tar [flags] archive-file-name files-to-archive –Some options: -c, --create, --delete, -r, --append, -t, --list, -u, --update 45

46. Guide to Parallel Operating Systems with Windows 7 and Linux Using Encryption in Fedora 13 Only user who encrypted file or an administrator can decrypt encrypted files gpg : –Most popular encryption utility –Syntax: gpg [--homedir name] [--options file] [options] command [args] –Some options: -c : encrypts with a symmetric cipher --decrypt [file]: Decrypts file, writes it to standard output o, --output file : writes output to a file 46

47. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files Finding files in the Windows 7 CLI –Searches are based on filenames or file contents –Pattern-matching methods used in content searches –Three commands used to search for files: DIR FIND FINDSTR 47

48. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the DIR Command DIR command supports wildcards Two wildcards used: question ( ? ), asterisk ( * ) Use ? to substitute for single unknown: –Example: DIR ?.cpp Command applies in current directory Lists all files beginning with any letter and ending in.cpp Use * to substitute for multiple unknown characters –A period extends search to include all file extensions –Example: DIR h* Lists all files beginning with “h” in the current directory 48

49. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the DIR Command (continued) 49 Table 7-11 Multiple-character substitutions for searches

50. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the DIR Command (continued) 50 Table 7-12 Single-character substitutions for searches

51. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the FIND Command FIND syntax: FIND [/V] [/C] [/N] [/I] string [[drive:][path]filename[...]] /V : displays all lines without the specified string /C : displays the count of lines that contain the string /N : displays line numbers with the displayed lines /I : ignores the case of characters when searching Example: FIND /I "Good" *.* Redirection operators: “ ” for output –Example: FIND /I "Football" FootballWinners.txt Finds all lines that contain Football in a file named Winners.txt 51

52. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the FINDSTR Command Use FINDSTR for more refined searches FINDSTR command syntax: FINDSTR [/B] [/E] [/L] [/R] [/S] [/I] [/X] [/V] [/N] [/M] [/O] [/P] [/C:string] strings [[drive:][path]filename[...]] Some switches: /B : matches the pattern at the beginning of a line /I : specifies that the search is not case sensitive Example: FINDSTR /I "good fool" *.* –Finds files containing “good” or “fool” 52

53. Book Title Finding Files with the FINDSTR Command 53 Figure 7-22 Finding files using the FINDSTR command Courtesy Course Technology/Cengage Learning

54. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the FINDSTR Command (continued) 54 Table 7-13 FINDSTR examples

55. Guide to Parallel Operating Systems with Windows 7 and Linux Using the FINDSTR Command with Regular Expressions Regular expressions: specify patterns of text Notation uses metacharacters and literal characters –Metacharacter: symbol with special meaning Examples: an operator or delimiter –Literal character: characters with no special meaning Examples: letters and numbers Some examples of regular expressions: w.*ing : strings starting with “w” and ending with “ing” [ABX] : matches any occurrence of “A”, “B”, or “C” 55

56. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files in Windows 7 with Windows Search Windows Search: most direct way to locate a file All or partial name of file/folder can be used to search Using quotation marks with Windows Search –To search on more than one word: Place the phrase in quotation marks Using wildcards with Windows Search –Add asterisk (*) to a search term to: Represent an unknown string of letters or numbers –Question mark (?): single character wildcard 56

57. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files in Windows 7 with Windows Search (continued) Using file sizes with Windows Search –Keyword size : used when you know approximate size of file –Example: resume size:<100KB Finds a file that is less than 100 kilobytes (KB) and contains the word resume –Some operators: <: less than <=: less than or equal to >: greater than =>: greater than or equal to 57

58. Guide to Parallel Operating Systems with Windows 7 and Linux Using Dates and Date Ranges with Windows Search Relative dates can be used in a search: –Example: today, tomorrow, or yesterday Word combinations can be used in a search: –Example: this, last, past, and coming with week, month, and year -> thisweek, nextmonth, pastmonth, and comingyear To find a file created in 2010: –Enter created:<1/1/2011 58

59. Guide to Parallel Operating Systems with Windows 7 and Linux Searching by Kind kind: command –Used to narrow search results –Example: vacation kind:photo or vacation kind: pictures Finds only pictures that include vacation in description kind:music –Finds all mp3 files, wma files, wav files, etc. 59

60. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files in Windows 7 with Windows Search (continued) Searching by type –type : command: Used to narrow search if result of kind command is too broad Searching by file properties –Windows Search: Indexes the filename and metadata for every file type Indexes the entire contents of many file types –To find Word documents created by Bill Jones: Enter type:doc author:BillJones 60

61. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files in Fedora 13 Finding files with the ls command in Fedora 13 ls command: Supports same basic wildcards used in Windows –Example: ls –l myfile* Finds files using ls command and wildcard expression 61

62. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the find Command in Fedora 13 How the find command works: –Searches a directory tree by evaluating an expression –Lists the files that match the expression –Returns 0 if all files are processed successfully –Returns greater than 0 if an errors occurs Three elements in the search expression: –Options: affect overall operation; always return true –Tests: these elements return a true or false value –Actions: have side effects; return a true or false value Elements are separated by operators; e.g., -and 62

63. Guide to Parallel Operating Systems with Windows 7 and Linux63 Table 7-16 Order of precedence for expressions in the Fedora 13 find command

64. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the find Command in Fedora 13 (continued) Some options used with the find command: –-xdev : does not check directories on other file systems –-ctimen : file’s status last changed n hours ago –-empty : file is empty (either regular file or directory) –-links n : file has n links Example 1: find /etc –type d | more –Locates directories Example 2: find /etc –type l | more –Locates links 64

65. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the find Command in Fedora 13 (continued) xargs command: –Often piped with the find command to construct an argument list –Syntax: xargs [options] [command] To locate files that include a certain string pattern: find. -name ’myfile*’ -print | xargs - n2 grep ’compression’ find. -name ’myfile*’ -print | xargs - n2 grep ’compression6’ find. -name ’myfile*’ -print | xargs - n2 grep ’compression[46]’ 65

66. Guide to Parallel Operating Systems with Windows 7 and Linux Finding Files with the find Command in Fedora 13 (continued) grep command: –Syntax: grep [options] [-e PATTERN | -f FILE] [FILE...] –Searches named input files for lines that contain a match of the given PATTERN –By default: prints matching lines –Some options: -c –count : suppresses normal output -f FILE --file=FILE : obtains patterns from FILE -H --with-filename : prints filename for each match 66

67. Guide to Parallel Operating Systems with Windows 7 and Linux Summary Files can have different types of contents File attributes: –Provide information about a file’s access privileges As directories are built, more files are added Using the Search feature in Windows 7: –You can locate files by their contents, as you can with the FINDSTR command File compression: –Saves disk space by removing duplicated data in files 67