红联Linux门户
Linux帮助
当前位置: 红联Linux门户 > Linux编程与内核

Linux中硬链接和软链接的介绍

发布时间:2006-11-21 09:41:49来源:红联作者:flycocoon
　　首先要弄清楚,在Linux系统中,内核为每一个新创建的文件分配一个Inode(索引结点),每个文件都有一个惟一的inode号。文件属性保存在索引结点里，在访问文件时，索引结点被复制到内存在，从而实现文件的快速访问。

　　链接是一种在共享文件和访问它的用户的若干目录项之间建立联系的一种方法。Linux中包括两种链接：硬链接(Hard Link)和软链接(Soft Link),软链接又称为符号链接（Symbolic link）。

　　一、硬链接

　　硬链接说白了是一个指针，指向文件索引节点，系统并不为它重新分配inode。可以用:ln命令来建立硬链接。语法:

引用:
ln [options] existingfile newfile
ln[options] existingfile-list directory


　　用法: 第一种:为”existingfile”创建硬链接,文件名为”newfile”。第二种:在”directory”目录中,为”existingfile-list”中包含的所有文件创建一个同名的硬链接。常用可选[options] -f 无论”newfile”存在与否,都创建链接。-n 如果”newfile”已存在,就不创建链接。

　　下面举一些例子:

引用:
$ ls -il
13058 -rwx - - - - - - 1 longcheng longcheng 48 8月 5 16:38 file1
13059 -rwx - - - - - - 1 longcheng longcheng 57 8月 5 16:40 file2
$ ln file2 file2hard
$ ls -il
13058 -rwx - - - - - - 1 longcheng longcheng 48 8月 5 16:38 file1
13059 -rwx - - - - - - 2 longcheng longcheng 57 8月 5 16:40 file2
13059 -rwx - - - - - - 2 longcheng longcheng 57 8月 5 16:40 file2hard


　　注意在创建链接前,file1 显示的链接数目为1,创建链接后(1)file1和file1hard的链接数目都变为2;(2) file1和file1hard在inode号是一样的(3) file1和file1hard显示的文件大小也是一样。可见进行了ln命令的操作结果：file1和file1hard是同一个文件的两个名字，它们具有同样的索引节点号和文件属性，建立文件file1的硬链接，就是为file1的文件索引节点在当前目录上建立一个新指针。

　　链接数同时减一,只有将所有指向文件内容的指针,也即链接数减为0时，内核才会把文件内容从磁盘上删除。当前目录逻辑结构：(不好意思图没有显示出来)。

　　还可以在不同目录，但同一文件系统中建立文件的硬链接。设file1、file2在目录/home/longcheng/dir1中，下面的命令，在/home/longcheng中建立file2的硬链接。

引用:
ln file2 /home/longcheng/file2hard


　　下面的程序，是将dir1目录中所有文件，在目录dir2中建立硬链接

引用:
$mkdir dir2
$ln /home/longcheng/dir1/* /home/longcheng/dir2


　　如果使用了 ln -f existingfile newfile,如果newfile已经存在，则无论原来newfile是什么文件，只用当前用户对它有写权限，newfile就成为exisitngfile的硬链接文件。

　　尽管硬链接节省空间，也是Linux系统整合文件系统的传统方式，但是存在一下不足之处：

　　（1）不可以在不同文件系统的文件间建立链接

　　（2）只有超级用户才可以为目录创建硬链接。虽然很多树上说root用户可以创建，但是笔者在学习过程中发现即使是root用户也不能创建，我的系统是Redhat，内核2.4、2.6都试过，在其他系统中不知道是不是可以。
文章评论

共有 2240 条评论

  1. 217.69.176.* 于 2007-07-15 09:14:16发表:

    gioca http://www.freewebs.com/poker-719/giochi-7.html gioca regola crap http://www.freewebs.com/casino-834/craps-3.html regole crap regola baccarat http://www.freewebs.com/poker-549/baccarat-4.html regole baccarat giochi online http://www.freewebs.com/poker-989/giochi-9.html tavoli multigiocatori poker free baccarat play baccarat http://www.freewebs.com/casino-379/baccarat-01.html

  2. 72.232.63.* 于 2007-07-15 08:26:43发表:

    Thank you!
    ringtones cingular | ringtones samsung | beyonce ringtones | cingular ringtones | handy klingelton | ringtones for nokia | logos para movil | ringtones verizon | dzwonki true tone | free ring tones

  3. 72.232.63.* 于 2007-07-15 08:26:11发表:

    Good design!
    downloaden ringtones | justin timberlake ringtones | free mobile phone ringtones | free anime | star wars ringtones | free lg ringtones | ringtone uploader | ringtone converter | sprint free ringtones | christian ringtones

  4. 72.232.63.* 于 2007-07-15 08:25:03发表:

    Well done!
    free real ringtones | ringtones for motorola q | free alltel ringtones | free downloadable ringtones | free nextel downloads | ringtones for verizon | toques siemens | sonneries mobile | ringtone download | free nokia downloads

  5. 76.171.16.* 于 2007-07-15 08:25:02发表:

    http://www.getaportal.com/portals/casino-137/blackjack_1.html blackjack pagina web blackjack pagina web play video poker http://www.freewebs.com/poker-82/video-poker-6.html internet video poker casino slots http://www.freewebs.com/casino-379/slots-81.html sim slots gambling portals gambling games http://www.getaportal.com/portals/casino-241/gamble_1.html poker caribe internet caribbean poker portales internet http://www.getaportal.com/portals/poker-241/caribbean_poker_1.html

  6. 72.232.63.* 于 2007-07-15 08:24:49发表:

    Good design!
    free funny ringtones | free ringtones for us cellular | free motorola ringtone downloads | wav ringtones | motorola ring tones | gospel ringtones | free cricket ringtones | free mp3 ringtones | sonnerie sagem | ringtone mp3

  7. 72.232.63.* 于 2007-07-15 08:24:34发表:

    Nice site!
    ringtone composer | mp3 ringtone | suonerie per cellulari | sonneries alcatel | free mobile ringtones | centennial ringtones | centennial wireless ringtones | nextel ringtones | free wwe ringtones | klingeltoene samsung

  8. 68.175.33.* 于 2007-07-15 08:15:56发表:

    http://www.freewebs.com/casino-162/craps-7.html strategie crap strategie crap online poker game play poker online http://www.freewebs.com/poker-419/online-poker-9.html casino gaming casino gioca http://www.freewebs.com/casino-837/casino-game-7.html online videopoker play video poker http://www.freewebs.com/poker-818/video-poker-7.html casino internacional portales casino internacional internet http://www.getaportal.com/portals/casino-492/casino_internacional_1.html

  9. 0.0.0.* 于 2007-07-15 07:42:13发表:

    download ringtone ringtone http://www.quizilla.com/users/ringtone-79/journal/572491/ casinos descargas portal http://www.getaportal.com/portals/casino-863/casino_descargas_1.html casinos descargas linea http://www.getaportal.com/portals/casino-222/juego_seguro_1.html jugar seguro portales web jugar seguro portal web regole baccarat regole baccarat http://www.freewebs.com/poker-818/baccarat-5.html poker online poker on line http://www.freewebs.com/poker-719/online-poker-5.html

  10. 58.30.18.* 于 2007-07-15 07:15:46发表:

    play blackjack internet blackjack http://www.bloglines.com/blog/casino-527?id=23 free motorola ringtone free motorola ringtone http://www.quizilla.com/users/ringtone-695/journal/570946/ ringtones free ringtones http://www.quizilla.com/users/ringtone-696/journal/572713/ online blackjack http://www.freewebs.com/casino-418/blackjack-6.html internet blackjack poker online poker on line http://www.freewebs.com/poker-989/online-poker-7.html

  11. 68.175.33.* 于 2007-07-15 07:12:38发表:

    http://www.getaportal.com/portals/casino-827/keno_1.html keno portales web keno pagina internet free sprint ringtones lil wayne ringtones http://www.quizilla.com/users/ringtone-555/journal/572781/ premio dinero web premios dinero pagina web http://www.getaportal.com/portals/poker-438/premio_dinero_1.html juegos azar portal internet juegos azar portal web http://www.getaportal.com/portals/poker-216/juegos_azar_1.html download free ringtone http://www.quizilla.com/users/ringtone-135/journal/572258/ download free ringtone

  12. 0.0.0.* 于 2007-07-15 06:38:17发表:

    poker caribe internet http://www.getaportal.com/portals/poker-267/caribbean_poker_1.html caribbean poker portal jugar ruleta http://www.getaportal.com/portals/casino-492/roulette_1.html ruleta linea free ringtone free ringtone http://www.quizilla.com/users/ringtone-927/journal/572759/ online poker game play poker online http://www.freewebs.com/poker-719/online-poker-8.html regola baccarat regole baccarat http://www.freewebs.com/poker-558/baccarat-1.html

  13. 209.200.52.* 于 2007-07-15 06:26:37发表:

    free cingular ringtone free cingular ringtone http://www.quizilla.com/users/ringtone-807/journal/572420/ ganar premio paginas web ganar premios http://www.getaportal.com/portals/poker-914/ganar_premio_1.html ganar premio portal web http://www.getaportal.com/portals/casino-241/ganar_premio_1.html ganar premio portal web ringtones free ringtones http://www.quizilla.com/users/ringtone-79/journal/572838/ caribbean poker portales web poker caribe pagina internet http://www.getaportal.com/portals/poker-412/caribbean_poker_1.html

  14. 0.0.0.* 于 2007-07-15 06:22:17发表:

    http://www.freewebs.com/casino-591/blackjack-4.html internet blackjack play blackjack http://www.getaportal.com/portals/poker-216/ganar_dinero_1.html ganar dinero verdadero pagina web ganar dinero portal internet free ringtone ringtone http://www.quizilla.com/users/ringtone-555/journal/572718/ http://www.freewebs.com/casino-379/keno-11.html play keno online internet keno http://www.freewebs.com/casino-674/craps-7.html strategie crap craps online

  15. 65.26.178.* 于 2007-07-15 06:17:05发表:

    penis enlargement pill http://www.section-three.com/discgroup/_disc/00000fb8.htm penis enlargement pill gioco poker http://www.freewebs.com/poker-110/poker-3.html online poker premio dinero paginas internet premio dinero paginas internet http://www.getaportal.com/portals/casino-691/premio_dinero_1.html ganar dinero verdadero paginas web ganar dinero verdadero portal web http://www.getaportal.com/portals/poker-168/ganar_dinero_1.html free motorola ringtone http://www.quizilla.com/users/ringtone-928/journal/570906/ free motorola ringtone

  16. 130.39.11.* 于 2007-07-15 06:14:30发表:

    play blackjack online blackjack http://www.freewebs.com/casino-606/blackjack-8.html juego interactivo pagina web juego interactivo pagina web http://www.getaportal.com/portals/poker-438/juego_interactivo_1.html ringtone download ringtone http://www.quizilla.com/users/ringtone-488/journal/570843/ party poker poker games http://www.freewebs.com/poker-549/poker-5.html free cingular ringtones http://www.quizilla.com/users/ringtone-928/journal/571050/ free ringtones

  17. 67.187.223.* 于 2007-07-15 06:13:48发表:

    roulette online roulette game http://www.freewebs.com/casino-591/roulette-3.html giochi carte http://www.freewebs.com/poker-979/giochi-3.html tavoli da gioco poker http://www.bloglines.com/blog/casino-527?id=40 online roulette online casino roulette black jack internet online blackjack http://www.getaportal.com/portals/casino-633/blackjack_1.html casino slot internet slots http://www.freewebs.com/casino-228/slots-5.html

  18. 213.23.175.* 于 2007-07-15 05:38:48发表:

    selena ringtones selena ringtones http://www.quizilla.com/users/ringtone-807/journal/572771/ free ringtones free nokia ringtones http://www.quizilla.com/users/ringtone-126/journal/572521/ juegos downloads juegos downloads http://www.getaportal.com/portals/casino-328/juego_1.html best online casinos best online casinos http://www.getaportal.com/portals/casino-41/casino_1.html tragaperra online tragaperras portal internet http://www.getaportal.com/portals/poker-168/tragaperra_1.html

  19. 0.0.0.* 于 2007-07-15 05:36:30发表:

    poker on line poker on line http://www.freewebs.com/poker-82/online-poker-8.html roulette online internet roulette http://www.freewebs.com/casino-387/roulette-8.html http://www.getaportal.com/portals/casino-340/casino_descargas_1.html casinos descargas paginas internet casinos descargas portal internet gioco gratuito stanze di gioco http://www.freewebs.com/poker-656/gioco-8.html tramadol prescription http://www.msd.k12.or.us/schools/mhs/AlumDiscuss/00001381.htm tramadol prescription

  20. 67.181.241.* 于 2007-07-15 05:35:40发表:

    free craps http://www.bloglines.com/blog/casino-527?id=69 craps table juegos apuestas portal jugar apostar paginas internet http://www.getaportal.com/portals/poker-667/juegos_apuestas_1.html internet blackjack blackjack online http://www.bloglines.com/blog/casino-527?id=30 poker in linea game poker http://www.freewebs.com/poker-549/poker-9.html progressive slots play free slots machine http://www.freewebs.com/casino-987/slots-72.html

  21. 66.190.101.* 于 2007-07-15 05:34:24发表:

    free online blackjack game casino blackjack http://www.freewebs.com/casino-987/blackjack-32.html http://www.getaportal.com/portals/poker-216/casino_pagina_1.html casino paginas web casino paginas web http://www.bloglines.com/blog/casino-527?id=63 free online keno free online keno http://www.freewebs.com/poker-979/video-poker-2.html play video poker internet video poker roulette internet online roulette poker http://www.freewebs.com/casino-511/roulette-4.html

  22. 209.200.52.* 于 2007-07-15 05:30:44发表:

    caribbean poker pagina web caribbean poker internet http://www.getaportal.com/portals/poker-926/caribbean_poker_1.html casino slots casino slots http://www.freewebs.com/casino-228/slots-3.html juegos azar portales internet juegos azar portales internet http://www.getaportal.com/portals/casino-79/juegos_azar_1.html http://www.quizilla.com/users/ringtone-695/journal/571048/ free mp3 ringtones free ringtones juego gratis portales http://www.getaportal.com/portals/casino-41/juego_gratis_1.html juego gratis portales

  23. 220.194.46.* 于 2007-07-15 05:18:08发表:

    ganar dinero online ganar dinero online http://www.getaportal.com/portals/poker-880/ganar_dinero_1.html casino internacional portal http://www.getaportal.com/portals/casino-827/casino_internacional_1.html casino internacional pagina web pai gow poker linea pai gow poker online http://www.getaportal.com/portals/poker-880/pai_gow_1.html http://www.quizilla.com/users/ringtone-807/journal/572372/ black eyed pea ringtone black eyed pea ringtone ganar premio portales ganar premio portales http://www.getaportal.com/portals/casino-759/ganar_premio_1.html

  24. 61.18.164.* 于 2007-07-15 05:16:55发表:

    black eyed pea ringtones ringtones http://www.quizilla.com/users/ringtone-928/journal/571090/ poker room play poker http://www.getaportal.com/portals/casino-585/poker_1.html jugar poquer linea http://www.getaportal.com/portals/casino-487/poquer_1.html poquer web free sprint ringtones http://www.quizilla.com/users/ringtone-126/journal/572667/ free ringtones cingular ringtone http://www.quizilla.com/users/ringtone-90/journal/570983/ ringtone

  25. 68.104.233.* 于 2007-07-15 04:51:24发表:

    ringtones lil wayne ringtones http://www.quizilla.com/users/ringtone-582/journal/571101/ madonna ringtone http://www.quizilla.com/users/ringtone-79/journal/572368/ ringtone premios dinero premio dinero pagina internet http://www.getaportal.com/portals/poker-160/premio_dinero_1.html http://www.quizilla.com/users/ringtone-135/journal/572716/ free sprint ringtones ringtones free polyphonic ringtones free polyphonic ringtones http://www.quizilla.com/users/ringtone-167/journal/570704/

  26. 217.69.176.* 于 2007-07-15 04:47:54发表:

    roulette online ruleta juego descarga http://www.getaportal.com/portals/casino-691/roulette_1.html black jack portales casino blackjack http://www.getaportal.com/portals/poker-241/blackjack_1.html http://www.getaportal.com/portals/poker-216/juego_1.html jugar cartas internet juegos linea http://www.getaportal.com/portals/poker-160/pai_gow_1.html pai gow poker portal web pai gow poker portales web ringtone polyphonic ringtone http://www.quizilla.com/users/ringtone-126/journal/572471/

  27. 68.200.9.* 于 2007-07-15 04:37:27发表:

    http://www.freewebs.com/poker-191/baccarat-8.html regola baccarat regole baccarat internet blackjack black jack http://www.freewebs.com/casino-837/blackjack-8.html http://www.freewebs.com/casino-162/blackjack-1.html blackjack game online blackjack casino paginas internet http://www.getaportal.com/portals/poker-75/casino_pagina_1.html casino virtual paginas web casinos espana portales web casinos espana online http://www.getaportal.com/portals/casino-492/casinos_espana_1.html

  28. 0.0.0.* 于 2007-07-15 04:37:00发表:

    http://www.freewebs.com/casino-387/slots-2.html online slot machine online slot juego al instante portales juego al instante paginas internet http://www.getaportal.com/portals/casino-79/juego_al_instante_1.html online poker game online poker game http://www.freewebs.com/poker-428/online-poker-5.html free craps play craps online free http://www.freewebs.com/casino-379/craps-31.html free ringtone http://www.quizilla.com/users/ringtone-928/journal/570933/ free real ringtone

  29. 0.0.0.* 于 2007-07-15 04:10:48发表:

    polyphonic ringtones ringtones http://www.quizilla.com/users/ringtone-24/journal/570809/ poker gratuito poker gratuito http://www.freewebs.com/poker-161/poker-8.html http://www.bloglines.com/blog/casino-198 play keno online video keno play baccarat online baccarat http://www.freewebs.com/casino-379/baccarat-41.html http://www.bloglines.com/blog/casino-198?id=61 play roulette online roulette gambling

  30. 207.210.85.* 于 2007-07-15 04:09:16发表:

    http://www.freewebs.com/poker-161/online-poker-4.html play poker online poker online http://www.quizilla.com/users/ringtone-316/journal/572302/ free cell phone ringtone free ringtone poker online http://www.freewebs.com/poker-549/online-poker-8.html play poker online internet slot online slot machine http://www.freewebs.com/casino-496/slots-7.html online video poker internet videopoker http://www.freewebs.com/poker-161/video-poker-8.html

  31. 69.242.94.* 于 2007-07-15 04:08:30发表:

    online videopoker http://www.freewebs.com/poker-191/video-poker-2.html online videopoker http://www.quizilla.com/users/ringtone-67/journal/572574/ free mobile phone ringtones free motorola ringtones roulette gambling roulette online http://www.freewebs.com/casino-987/roulette-22.html http://www.freewebs.com/casino-987/roulette-02.html online roulette poker free online roulette internet slot machine casino slot http://www.freewebs.com/casino-244/slots-8.html

  32. 217.69.176.* 于 2007-07-15 04:07:51发表:

    http://www.freewebs.com/casino-985/casino-game-5.html casinos games casino games regola baccarat regole baccarat http://www.freewebs.com/poker-549/baccarat-2.html http://www.freewebs.com/casino-985/blackjack-7.html internet blackjack play blackjack free keno free keno http://www.bloglines.com/blog/casino-527?id=49 free nokia ringtones free nextel ringtones http://www.quizilla.com/users/ringtone-24/journal/570800/

  33. 0.0.0.* 于 2007-07-15 02:00:04发表:

    stanze di gioco in linea libere stanze di gioco migliori http://www.freewebs.com/poker-656/gioco-1.html verizon ringtone http://www.quizilla.com/users/ringtone-869/journal/572766/ selena ringtones http://destinychristianministries.org/_disc7/00000506.htm fioricet fioricet gioco gratuito http://www.freewebs.com/poker-719/gioco-8.html stanze di gioco free blackjack game http://www.getaportal.com/portals/casino-2877/blackjack_21.html online blackjack game

  34. 217.69.176.* 于 2007-07-15 00:40:15发表:

    ringtone cell phone ringtone http://www.quizilla.com/users/ringtone-555/journal/572459/ casino internacional portales web casino internacional portal http://www.getaportal.com/portals/poker-998/casino_internacional_1.html http://www.quizilla.com/users/ringtone-488/journal/570835/ free ringtone download free cingular ringtone premios dinero pagina internet http://www.getaportal.com/portals/casino-340/premio_dinero_1.html premios dinero pagina internet download free ringtone beatles ringtones http://www.quizilla.com/users/ringtone-24/journal/570812/

  35. 68.84.85.* 于 2007-07-14 21:35:52发表:

    http://www.quizilla.com/users/ringtone-135/journal/572407/ cell phone ringtone cell phone ringtone premio dinero portal web premio dinero portal http://www.getaportal.com/portals/casino-192/premio_dinero_1.html http://www.getaportal.com/portals/casino-79/casino_internacional_1.html casino internacional portales casino internacional portal internet ganar dinero online ganar dinero verdadero online http://www.getaportal.com/portals/poker-735/ganar_dinero_1.html lil wayne ringtone http://www.quizilla.com/users/ringtone-126/journal/572449/ lil wayne ringtone

  36. 0.0.0.* 于 2007-07-14 21:31:51发表:

    selena ringtone madonna ringtone http://www.quizilla.com/users/ringtone-696/journal/572412/ blackjack pagina internet http://www.getaportal.com/portals/poker-334/blackjack_1.html casino blackjack free real music ringtone sprint http://www.quizilla.com/users/ringtone-67/journal/572243/ free sprint ringtone pai gow poker internet pai gow poker pagina internet http://www.getaportal.com/portals/poker-75/pai_gow_1.html download free cingular ringtones http://www.quizilla.com/users/ringtone-696/journal/572666/ download free verizon ringtones

  37. 209.200.52.* 于 2007-07-14 21:24:06发表:

    http://www.quizilla.com/users/ringtone-927/journal/572747/ free cingular ringtones free sprint ringtones keno portal web http://www.getaportal.com/portals/casino-585/keno_1.html keno web poker free http://www.getaportal.com/portals/poker-113/poker_1.html cartas poker juegos azar paginas web http://www.getaportal.com/portals/poker-267/juegos_azar_1.html juegos azar paginas internet ringtone celtic frost ringtone http://www.quizilla.com/users/ringtone-67/journal/572346/

  38. 209.200.52.* 于 2007-07-14 21:02:38发表:

    lil wayne ringtone lil wayne ringtone http://www.quizilla.com/users/ringtone-555/journal/572499/ juego interactivo online http://www.getaportal.com/portals/poker-94/juego_interactivo_1.html juego interactivo portales free mp3 ringtone free mp3 ringtone http://www.quizilla.com/users/ringtone-79/journal/572218/ http://www.quizilla.com/users/ringtone-555/journal/572486/ madonna ringtone dave hollister ringtone juego gratis portales internet jugar gratis portal http://www.getaportal.com/portals/poker-229/juego_gratis_1.html

  39. 0.0.0.* 于 2007-07-14 20:53:34发表:

    http://www.freewebs.com/casino-987/keno-42.html play keno online free online keno http://www.getaportal.com/portals/poker-3863/slots_32.html free slots free slots online slots online slots http://www.getaportal.com/portals/poker-3863/slots_02.html http://www.getaportal.com/portals/casino-2877/baccarat_31.html online baccarat casino baccarat blackjack game blackjack game http://www.freewebs.com/casino-379/blackjack-31.html

  40. 210.49.50.* 于 2007-07-14 20:52:42发表:

    http://www.freewebs.com/casino-987/keno-42.html play keno online free online keno http://www.getaportal.com/portals/poker-3863/slots_32.html free slots free slots online slots online slots http://www.getaportal.com/portals/poker-3863/slots_02.html http://www.getaportal.com/portals/casino-2877/baccarat_31.html online baccarat casino baccarat blackjack game blackjack game http://www.freewebs.com/casino-379/blackjack-31.html

  1. 首页上一页 10 11 12 13 14 下一页 尾页

频道文章

最新教程

随机推荐

关于我们 | 合作 | 联系我们

© linuxdiyf.com 红联Linux门户 版权所有