ѫe@`yLinux ɮvPؿtmzAѨ Linux y𪬥ؿzAUӴNonڪӷdw@ǰ򥻪|DFIoǰDA̭nLy|zPy۹|zNqաIAѤ@UI

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• |P۹|G

b}lؿeAAnAѤ@Uҿתy|, PATHzA쪺OGOy۹|zPy|zHpGAٰOoe@eܡAٰOo Linux ̭ؿOe{y𪬥ؿzpANO䪺աInFA]AݭnbN@ӥؿUܴڥؿ etc UAANӭnϥΡy cd /etc zoӱpAo]NOҿתy|zALOqڥؿsgWӪ@ӱpAҥHקAb@Ӹ|{o@ӫOA|NAʨӸ|UCpGڬOϥΡy cd etc zOHܧAnyثeoӥؿU etc ؿzApiO@˪Iq`Ĥ@IJ Linux ϥΪ̱`|do@Ӹ|[I
@
• |G|gky@wѮڥؿ / g_zAҦpG /usr/share/doc oӥؿC
• ۹|G|gkyO / g_zAҦp /usr/share/doc n /usr/share/man UɡAiHgG ycd ../manzoNO۹|gkաI
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۹|P|F_rIHܡIiuOF_FI]zgF@ӮMAoӮM@ݭnTӥؿAOO etc, bin, man oTӥؿAMӥѩ󤣦PHww˦bPؿUA]Ҧw˪ؿO /usr/local/packages/etc, /usr/local/packages/bin /usr/local/packages/man ALAoww˦b /home/packages/etc, /home/packages/bin, /home/packages/man oTӥؿAаݦpGݭnΨ쵴|ܡAO_ܳ·ЩOHOIp@ӨCӥؿUFN_ӡIoӮɭԬ۹|gkN㪺SOnFI
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~ApGzڤ@ˡAwN|WrgܪAnۤvDӥؿObF򪺡AҦpG/data4/staiwan19961109/models-3/smoke oӥؿAӥt@ӥؿb /data4/staiwan19961109/models-3/cctm AڱqĤ@ӭnĤGӥؿhܡAgKHMOy cd ../cctm zKoIaI
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nFAJMnͨؿoӪFA۵MNݭnAѤ@UDZ`ΪؿyŸzNNqաI
@

.     Nhؿ ..    NWhؿ ~     Nۤvaؿ ~user N user oӤHaؿ

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Uڭ̭nӽͤ@ͥؿP|Xӱ`ΪOG

• cd     ܴؿ
• pwd    ܥثeؿ
• mkdir إߤ@ӷsؿ
• rmdir R@Ӹ̭OŪťؿ
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• cd P pwd

oӫODnObyܴثeؿzPyܥثeҦbؿzu@AU@L̪γ~PykaI
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• cd

ykG

[root @test /root ]# cd [۹|ε|]  ѼƻG |y۹|zPy|zOAФdUpoI dҡG [root @test /root]# cd ..@@@@@@@<==^W@hؿ [root @test /root]# cd ../home@@@@ <==۹|gk [root @test /root]# cd /var/www/html@ <==|gk [root @test /etc]# cd@@@@@@@@@<==^ϥΪ̪aؿ [root @test /etc]# cd ~ @@@@@@@ <==^ϥΪ̪aؿI [root @test /etc]# cd ~test@@@@@@<==^ test oӨϥΪ̪aؿ

G
cd O change directory YgAoOΨܴu@|OC`NA|P cd Osb@ӪŮI@nJ Linux tΫAroot |b root aؿAY /root UAܩϥΪ̷|bw] /home/username UAҦp ID vbird AhH vbird nJA| /home/vbird oӸ|UCOKI^W@hiHΡy cd .. zӨ۹|iy cd ../birdzAܩ󵴹|hO cd /usr/sbin I`NAbeܦr|ܸ|W١I~Aaؿ٦@ӥNXANOy ~ zŸIҦpWҤliHo{AϥΡy cd ~ ziH^ӤHaؿYhOI ~ApGA Linux D testing bAAnLaؿhAiHUFy cd ~testingzߨh testing aؿoI
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• pwd

ykG

[root @test /root ]# pwd  dҡG [root @test root]# cd /home/test [root @test test]# pwd  /home/test             <==ܥثeAҦbؿI

G
pwd O print working directory YgA]NOܥثeҦbؿOAҦpbWӪ̫᪺ؿO /home/test oӥؿAOܦr test ApGAQnDثeҦbؿAiHJ pwd YiG
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~AѩܦhMҨϥΪؿWٳۦPAҦp /usr/local/etc ٦ /etc AOq` Linux ȦCX̫᭱@ӥؿӤwAoӮɭԧANiHϥ pwd ӪDAҦbؿoIKodؿAGKK
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---

• mkdir P rmdir ޲zؿG

npإߧRؿOH²rIN mkdir P rmdir AݥXӤFܡHSաINO make/remove directory YgIݭnΧaI
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• mkdir

ykG

[root @test /root ]# mkdir [-mp] [ؿW] ѼƻG -m G]wɮתvI]wAݭn umask oӤeyI -p GUANWؿjإ߰_ӡI dҡG [root @test /root]# cd tmp [root @test /tmp]# mkdir test<==إߦW٬ test ؿ [root @test /tmp]# mkdir -p test1/test2/test3/test4 <==إ test2...Whؿ [root @test /tmp]# mkdir -m 711 testqq  <==إv 711 ؿI [root @test /tmp]# ll test* drwxrwxr-x    2 test    test        4096 Feb  6 20:47 test/ drwxrwxr-x    3 test    test        4096 Feb  6 20:48 test1/ drwx--x--x    2 test    test        4096 Feb  6 20:48 testqq/

G
pGQnإ߷sؿܡANϥ mkdir aI LAЪ`NIbw]pUAAһݭnؿo@h@hإߤ~IҦpGpAnإߤ@ӥؿ /home/bird/testing/test1A򭺥n /home M /home/bird AA /home/bird/testing nsbA~iHإ test1 oӥؿIpS /home/bird/testing ɡANSkإ test1 ؿoILA{bӧ²榳ĪkաINO[W -p oӰѼƳIAiHUFGy mkdir -p /home/bird/testingzhtη|۰ʪAN /home, /home/bird, /home/bird/testing ̧Ǫإ߰_ؿIåBApGӥؿӴNwgsbɡAtΤ]|ܿ~TIּ֪aI ^_^
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• rmdir

ykG

[root @test /root ]# rmdir [-p] [ؿW] ѼƻG -p GNWhؿ]RaI dҡG [root @test /root]# rmdir test<==RW٬ test ؿ [root @test tmp]# ll drwxrwxr-x    3 test    test        4096 Feb  6 20:48 test1/ [root @test tmp]# rmdir test1 rmdir: `test1': Directory not empty [root @test tmp]# rmdir -p test1/test2/test3/test4 [root @test tmp]$ ll

G
pGQnإߧR¦ؿɡANϥ rmdir aIҦpNإߪ test Aϥ rmdir test YiIЪ`NIؿݭn@h@hR~IӥBQRؿ̭w٦LؿɮIpGnNҦؿUF卖OHIoӮɭԴNϥ rm -rf test oILA٬Oϥ rmdir MIILAA]iHեH -p Ѽƥ[JAӧRWhؿI
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---

• ܼ PATH

bLF|B۹|POUF觋Azӷ|yL`N@ƱANOGyڥiHb /root U /bin/ls oɮשOHzrIڥiH ls N@wiHܥX@ǰTӤ|䤣ɮשOHoO]ܼ PATH UҭPrIڭ̦b@ӫOɭԡAtη|̷ PATH ]whC PATH wq|UjMɮסAjM쪺OɮץQ椧I{bAФUF echo $PATH A echo yܡBLXzNA PATH e[ $ ܫ᭱OܼơAҥHY|ܥXثe PATH FI
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[root@test root]# echo $PATH /sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin

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`NFܡHաI /bin b PATH ]wAҥH۵MNiH䪺 ls աI
 
• pGAN ls ʨ /root UܡAMAۤv]b /root UAOA ls ɭԡALNOzAHHoO] PATH S /root oӥؿAӧASN ls ʨ /root UFA۵MtδN䤣iɤFA]N|iDAA command not found IӫJAoذDOHӤkA@GN /root |[J PATH IpW[HiHϥΡG

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PATH=$PATH:/root
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oؤ觋ӼW[YiIt@ؤ觋hOϥΧɦWAYϥά۹ε|ӰAҦpG
@
  /root/ls
  ./ls
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]bP@ӥؿAӧڭ̤SDbP@ӥؿؿŸy . zA]ANHW ./ls Ӱ]iHIoذ觋Hzӷ|ܱ`~I
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• pGڦ ls ɮצbPؿAҦp /usr/local/bin/ls UP /bin/ls ڤUF ls ɭԡA ls |QH٥λANX PATH ̭ӥؿQdߡAhӥؿUɮ״N|QFI
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• xIJMpܡA򬰦󤣭nb PATH ̭[J . oӥؿAp@ӪܡANiHbҦbؿɮפFܡH] . NҦbؿIOo˨SIOSQLApGYѡAYөǩǪϥΪ̦b /tmp ̭gF@ ls ɮסALO`ɮסAAb /tmp U ls ɡAHISAi|yСzAҥHoAFw_AijNy . z[J PATH jMI

ͤFͥؿP|AAӰQפ@Uɮת@ǰ򥻺޲zaIɮ׻Pؿ޲zWA~GyݩzByzByRɮzΡyɮשΥؿzAѩɮ׻Pؿ޲zb Linux OܭnIרOCӤHۤvaؿƤ]ݭn`N޲zIѩڭ̦b{ɫAtιw]@ӷjM|ǡApGӥHWۦPɦWɤObP|ɡAANݭnSOdNoIo̧ڭ̨ӽͤ@ͦɮ׻Pؿ@ǰ¦޲zaI

ls ɮצW١Bݩʵ
cp ɮשΥؿ
rm RɮשΥؿ
mv ɮשΥؿ
@

---

ls

ykG

[root @test /root ]# ls [-ailS] ѼƻG -a       :ɮ׳CX]sPɡ^ -i       :LX inode -l       :CXAsPɮפjpƵ -S       :HɮפjpƧ --color=never     :nC --color=always    :C --color=auto      :ѨtΦۦP_I dҡG [root @test /root]# ls -al total 48 drwxr-x---    4 root     root         4096 Mar 10 00:37 . drwxr-xr-x   21 root     root         4096 Mar 10 20:16 .. -rw-------    1 root     root          524 Mar 10 00:40 .bash_history -rw-r--r--    1 root     root           24 Jun 11  2000 .bash_logout -rw-r--r--    1 root     root          266 Jun 11  2000 .bash_profile -rw-r--r--    1 root     root          249 Mar  6 20:50 .bashrc -rw-r--r--    1 root     root          210 Jun 11  2000 .cshrc drwx------    2 root     root         4096 Mar  9 11:06 .gnupg -rw-------    1 root     root          524 Jan 16 14:37 .mysql_history drwx------    2 root     root         4096 Mar  9 11:06 .ssh -rw-r--r--    1 root     root          196 Jul 11  2000 .tcshrc -rw-r--r--    1 root     root         1126 Aug 24  1995 .Xresources [root @test /]# ls bin   dev    etc   lib         misc  opt   root  tftpboot  usr boot  disk1  home  lost+found  mnt   proc  sbin  tmp       var [root @test /]# ls --color=never bin   dev    etc   lib         misc  opt   root  tftpboot  usr boot  disk1  home  lost+found  mnt   proc  sbin  tmp       var [root @test /]# ls -al|more

G
ٰOoڭ̦bɮת@ݩʻPؿc@ܡHIաIڭ̨ϥΪĤ@ONO ls աIq`ڭ̳ݭnDoɮצW١yؿz٬OyɮסzHҥHAڳwϥΡy llzoӫOA꨺NOls -l NաIצpAAiHյ۰oOӵAɮסI
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Ъ`NInѰOAƪDnNNIרOeXӥDnݩIt~AASo{pGbݥH telnet Ϊ̬O putty su{nJDɫAѩ Linux w]ϥΦC⪺觋ܤ觋AOW@ˡAŦ⪺rˮڥNOݨIoӮɭԳq`ڳOϥΡyls --color=never zӥᱼCIpGQ ls w]SC⪺ܡAiHb /root/.bashrc Ϊ̬OAaؿ .bashrc oɮפ[JUo@G

alias ls='ls --color=never'

o˴NiHChFIܩ alias ObFHڭ̨F bash o shell ɭԦAӽͧaI
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---

cp

ykG

[root @test /root ]# cp [-drsu] [ӷ] [ت] ѼƻG -d@@@@@Gbi copy ɭԡApGO copy link ɮסAY[ѼơAhw]p|N link 쪺lɮ @@@@@@@copy تaAY[ -d ɡAh link ɮץiʤʪN link oӱ|تaI -r@@@@@GiHiؿ copy I -s          GsɡAӤ copy NIP ln OۦP\I -u, --updateGpGӷɤsAΪ̬OSتɡA~|i copy ʧ@IiΩƥʧ@I dҡG [root @test /root]# cp    .bashrc bashrc      <==N .bashrc bashrc oɮסI [root @test /root]# cp -r /bin /tmp/bin        <==oӥ\NnաIoOΨ copy ӥؿѼơI [root @test /root]# cp -s .bashrc bashrc         <==N .bashrc إߤ@ӳsɡAɦW bashrc [root @test /root]# cp -u /home/.bashrc .bashrc  <==ˬd /home/.bashrc O_P .bashrc PApGPܴN}l copy @IpGۦPhʧ@I

G
oӫO|`Ψ쪺I]ڭ̱o``ݭn copy ƧrIҥHݭnAѤ@UIpGAǫܤjɮתݭnƥAoɮתsvܧCACƥݭnb copy @ܡHݨӬOݭnFIAiHϥΡycp -u ӷ تzӳƥIp@ӡAɮ׳QܹLA~|i copy ʧ@I
@

---

rm

ykG

[root @test /root ]# rm [-fir] [ɦW] ѼƻG -i     :ѨϥΪ̽T{]oOw]ȡ^ -r     :`ANO@ASF謰N -f     :force ANOjOաI dҡG [root @test /root]# cp .bashrc bashrc<==إߤ@ӷsɮסA bashrc [root @test /root]# rm bashrc           <==|ܦpUܡG rm: remove `bashrc'? [root @test /root]# mkdir testing [root @test /root]# cp .bashrc testing [root @test /root]# rmdir testing rmdir: `testing': Directory not empty   <==ѩ testing ̭ .bashrc AҥH夣I [root @test /root]# rm -rf testing      <==RӥؿUҦɮ׻Pؿ

G
oOOA۷ dos U del OIo̭n`NOAq`b Linux tΤUAFɮ׳Q~AҥHwg -i oӰѼơA -i OCɮ׳Qe|ϥΪ̽T{@AHw~ɮסIӦpGnsؿUF卖@_ܡAҦplؿ̭٦lؿɡANnϥ -rf oӰѼƤFILAϥΡy rm -rf zoӫOeAФdU`NFA]Aӥؿɮסy֩wz|Q root I]tΤ|A߰ݧAO_n屼I ҥHOӶWYOUFIoSO`NILApGATwӥؿnFAϥ rm -rf Ӵ`O觋I
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---

mv

ykG

[root @test /root ]# mv [-u] [ӷ] [ت] ѼƻG -u   :P˪A update ²gAӷɤتٷsɫ~|ʧ@I dҡG [root @test /root]# cp .bashrc bashrc [root @test /root]# mv bashrc bashrc.old [root @test /root]# mv bashrc bashrc2 /tmp<==N bashrc P bashrc2 ʨ /tmp oӥؿUIЪ`NA̫@Ӥ~O̲תؼСALO SOURCE

G
oOhNIAnɮשΥؿɫAIoӫONܭnաIP˪AA]iHϥ -u ( update )ӴշsɮסAݬݬO_ݭnhoIt~@ӥγ~NOyܧɦWIzAڭ̥iHܻϥ mv ܧ@ɮתɦWOI
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---

basename

ykG

[root @test /root ]# basename [ؿ] ѼƻG dҡG [root @test /root]# basename /usr/local/etc etc oӫO|N᭱[ؿ]^X̫᭱ӥؿɮסA HWҤlӬݡA /usr/local/etc etc OؿɮסA L|Q^XӡA]LO̫@ӥX{NNI

G
oӫOᦳINLiHN@ӥؿɮת̫@өNNqXӡIҥHAӦpGAnϥܼơAåBX̫@Ӹ(׬Oɮ٬Oؿ)AϥγoӪNNաI ^_^
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---

dirname

ykG

[root @test /root ]# dirname [ؿ] ѼƻG dҡG [root @test /root]# dirname /usr/local/etc /usr/local P basename ۤϡALȬOqXӫeyؿzI

G
oӫOP basename ۤϪաIIܦnaIo]̱`Φbڭ̲ĤTn Shell DzߤIγ̦haӬO scripts աIγo_J^ƪeIΪܡI

ڭ̴쪺uObɮת~[AΪ̬OʻPƻs@ɮשΥؿӤwApGڭ̭n@ɮתeɡAӦpOnOHIo̦۷h쪺OiHӤɤ@UG̱`ϥΪɮפeOiHO cat P more less FI~ApGڭ̭ndݤ@ӫܤjɮס]nXMBɡ^AOڭ̥uݭnݪXrӤwAӦpOnHI tail rA~A tac oӫO]iHFInFAUӫOγ~aI

cat  ѲĤ@}lɮפe
tac  q̫@}lܡAiHݥX tac O cat ˵ۼgI
more @@ɮפe
less P more AO more nOALiHe½I
head uYX
tail uݧڴX
nl   ܪɭԡADX 渹I
od   HGi쪺觋ŪɮפeI

Uڭ̨ӽͤ@ͨCӫO򥻥ΪkaI

---

cat

ykG

[root @test /root ]# cat [-nAE] ѼƻG -n:   ܮɡAs渹LXùWC -A:   N DOS U <tab> P_rųCXӡI -E:   N DOS s𫍧󤤡AȦCX _rťXӡI dҡG [root @test /root]# cat ~/.bashrc         <== .bashrc oɮ # .bashrc # User specific aliases and functions PATH="/bin:/sbin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:$PATH" alias rm='rm -i' alias cp='cp -i' alias mv='mv -i' alias ll='ls -l --color=never' [root @test /root]# cat ~/.bashrc -n      <== .bashrc åB[W渹I      1  # .bashrc      2      3  # User specific aliases and functions      4  PATH="/bin:/sbin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:$PATH"      6  alias rm='rm -i'      7  alias cp='cp -i'      8  alias mv='mv -i'      9  alias ll='ls -l --color=never' [root @test /root]# cat -A regexp.txt This is a cat, however, I need a dog.^M$ I want to "Happy" and <Happy> and /Happy/ here.^M$ OK! ^Ieverythins is OK^M$ Now, I will eat my food^M$ are you ^Ifinished your work^M$ what do you 123 goto where^M$ ܥX DOS ɮתXӯSŸAHWɮ׬ҡA io{ ^M _ŸAӨC檺 $ ŸA ܩ ^I hO <tab> աI

G
KKI Linux ̭yߡzHIIOA cat O Concatenate ]s^²gADn\ON@ɮתes򪺦LXbùWIҦpWҤlAڭ̱NnѼ .bashrc LXӡIpG[W -n ܡAhC@eٷ|[W渹Icat ֥ΡIAɮפeƶWL 40 HWAKKIڥӤάݡIҥHAtX more Ϊ̬O |more ӰnI~ApGO@몺 DOS ɮ׮ɡANݭnSOdN@ǩ__ǩǪŸFAҦp_P<tab>AnܥXӡANo[J -A ѼƤFIC
@

---

tac

ykG

[root @test /root ]# tac [ɦW] ѼƻG dҡG [root @test /root]# tac ~/.bashrc <==o{FSHϦVLXI fi         . /etc/bashrc if [ -f /etc/bashrc ]; then # Source global definitions alias h='history' alias lm='ls -al|more' alias ll='ls -l' # alias ll='ls -l --color=never' alias mv='mv -i' alias cp='cp -i' alias rm='rm -i' export PATH PATH="/bin:/sbin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:$PATH" # User specific aliases and functions # .bashrc

G
tac oӦnFI򻡩OHԲӪݤ@UA cat P tac ASo{rIաI tac nON cat ϼgLӡAҥHL\N cat ۤϰաA cat OѡyĤ@̫@sܦbùWzA tac hOyѳ̫@Ĥ@ϦVbùWܥXzAܦnaI
@

---

more

ykG

[root @test /root ]# more [ɦW] ѼƻG dҡG [root @test /root]# more ~/.bashrc  <==@@ɮפe [root @test /]# ls -al | more <==@@N ls eܥX

G
more uOӫܦΪOIڦnwIAɮפӤjɫAϥ cat NSkݲMIoӮɭԧAiHϥ more Ӱʧ@Imore ]iHΨӰ޽uPɰ椧ΡIҦpAb find oӴM䪺OɡAiHPɨϥ |more AhjMGiH@@CXI޽u( pipe )Ϊkڭ̦b bash shell aAӽ͡I
@

---

less

ykG

[root @test /root ]# less [ɦW]  ѼƻG  dҡG  [root @test /root]# less ~/.bashrc

G
less Ϊk_ more S[uʡA򻡩OHb more ɭԡAڭ̨èSkVe½Au੹᭱ݡAYϥΤF less ɡAINiHϥ [pageup] [pagedown] 䪺\өe½ݤAz@AOOeϥΨ[ݤ@ɮתeFOIH
@
more P less γ~PΪkuOܼsաIAAiHb more P less eiyjMzu@IpiOHڭ̥H less ӻnFApGAQnD /etc/man.config oɮ׸̭S@ӥs GER jgrAiHG
@

[root @test /root ]# less /etc/man.config  仡G /wordGb /etc/man.config oɮפjM word oӦrꪺҦb q    G} less e

@
MbJ / Aз|ʨ̥UݿJAoӮɭԱzunJArꤧAN|۰ʪAXӸroI
@

---

head

ykG

[root @test /root ]# head [-n number] [ɦW] ѼƻG -n G number dҡG [root @test /root]# head ~/.bashrc  <==w]pUAYQ [root @test /root]# head -n 20 ~/.bashrc<==YGQI

G
head ^NNOyYzաAoӪF𫍧Ϊk۵MNOܥX@ɮתeXoISINOoˡIYS[W -n oӰѼƮɡAw]uܤQAYun@OHN[Jy head -n 1 filename zYiI
@

---

tail

ykG

[root @test /root ]# tail [-n number] [ɦW] ѼƻG -n G number dҡG [root @test /root]# tail ~/.bashrc [root @test /root]# tail -n 5 ~/.bashrc <==u̫ܳ᭱I

G
head ۵MN tail ( ) oISIo tail Ϊk head ΪkthAuOܪO᭱XNOFIw]]OܤQAYnܫDQAN[ -n number ѼơI
@

D@GpڷQn ~/.bashrc 11 20 OH G oӤAQ@QAb 11 20 Aڨe 20 AAQAҥHGNOGy head Vn 20 ~/.bashrc | tail Vn 10 zAo˴NiHo 11 20 椧eFIO̭AΨ޽uROAݭnbĤTgɭԤ~I

@

---

nl

ykG

[root @test /root ]# nl [ɦW] ѼƻG dҡG [root @test /root]# nl ~/.bashrc

G
nl SOHo]SAoӫOΪk cat -n ΪkA]NOyiHLX渹zOӬdɮװաI]OnΪI
@

---

od

ykG

[root @test /root ]# od [ɦW] ѼƻG dҡG [root @test /root]# od ~/.bashrc 0000000 020043 061056 071541 071150 005143 021412 052440 062563 0000020 020162 070163 061545 063151 061551 060440 064554 071541 0000040 071545 060440 062156 063040 067165 072143 067551 071556 0000060 050012 052101 036510 027442 064542 035156 071457 064542 0000100 035156 072457 071163 071457 064542 035156 072457 071163 0000120 061057 067151 027472 071565 027562 067554 060543 027554 0000140 061163 067151 027472 071565 027562 067554 060543 027554 0000160 064542 035156 050044 052101 021110 062412 070170 071157 0000200 020164 040520 044124 005012 066141 060551 020163 066562 0000220 023475 066562 026440 023551 060412 064554 071541 061440 0000240 036560 061447 020160 064455 005047 066141 060551 020163 0000260 073155 023475 073155 026440 023551 021412 060440 064554 0000300 071541 066040 036554 066047 020163 066055 026440 061455 0000320 066157 071157 067075 073145 071145 005047 066141 060551 0000340 020163 066154 023475 071554 026440 023554 060412 064554 0000360 071541 066040 036555 066047 020163 060455 076154 067555 0000400 062562 005047 066141 060551 020163 036550 064047 071551 0000420 067564 074562 005047 021412 051440 072557 061562 020145 0000440 066147 061157 066141 062040 063145 067151 072151 067551 0000460 071556 064412 020146 020133 063055 027440 072145 027543 0000500 060542 064163 061562 056440 020073 064164 067145 004412 0000520 020056 062457 061564 061057 071541 071150 005143 064546 0000540 000012 0000541

G
nFApG@ӫD ASCII ɮשOHҦp binary ɮסIϥ vi ڥNOݤۡoӮɭԬݨӥuϥαNӸƥHƭȤkŪXӰաINO od oӫOŪXIoӪFiHΨӿXӸƬQiB16i쵥Ʈ榡ILoӪFu{viΰաI]LXӪF卖OƦrΰOơ

Linux ɮݩ eڭ̥iHD@ɮצYzݩʡA]A ( r, w, x ) ݩʡAάO_ؿ (d) Pɮ (-) Ϊ̬Os (l) ݩʡInקݩʪkbe]LFAo̦A[jɥR@UI~Aѩ Linux ٥iH]wLtΦwݩʡAϥ chattr ӳ]wAӥH lsattr ӬdݡA̭nݩʴNOiH]w䤣iק諸SʡIsɮת֦̳iקIoݩʥiO۷nAרObwW] security ^I

chown ɮת֦H
chgrp ɮתݸs
chmod ɮתigBiŪBi浥ݩ
umask ܹw]إɮשΥؿɪݩ
chattr ɮתSݩ
lsattr ɮתSݩʡI

---

• chown

ykG

[root @test /root ]# chown [-R] user:group [ؿW] ѼƻG -R    :`NӥؿUҦɮ׳令 user P group W١I dҡG [root @test /root]# mkdir /home/test/testing  <==b /home/test oӮaؿإߤ@ӦW testint lؿ [root @test /root]# cp * /home/test/testing [root @test /root]# chown test /home/test/testing [root @test /root]# chown -R test:test /home/test/testing<==NӥؿUҦؿɮקܬ test ֦

G
e@ӳ`~AӤ|No˧ѰOFaHIѩ chown ϥνdsAҥHo̦ALƲߤ@U chown NnA chgrp Ц^e@e[I
@
Ooɮצy֦HzΡy֦szaAo chown NObܾ֦̪OC𫎆IJ Linux Bͳ̮eǪ@ӿ~b̩OHNOH root copy @ɮס]θ|^@ϥΪ̡]] test ^ɡAѰONɮתҦH令 test FIѩƻs̬O root ҥHɮפ]|O root ҦI test M]NקɮפFI
@
bWҤlAy chown test /home/test/testing zoӫOu|Nӥؿܦ test AO group MO root IҥHAiHϥΡy chown test:test /home/test/testing zAsϥΪ̸sճLܤ@UoILݭn`NOAoӫOuܤFyؿz ҦvӤwIboӥؿUF]nܪܡAӦpHIANϥ -R oӰѼƧYiI
@


---

• chmod

ykG

[root @test /root ]# chmod [-R] [parameter] [ؿW] ѼƻG -R   :`@NӥؿɮקܤI dҡG [root @test /root]# chmod 777 .bashrc

G
ٰOobyɮݩʻPtz@aI@ɮשΥؿܤ֦EݩʡATӤTӤ@աA@TաIӥiHϥμƦrӷ@ܴݩʪѦҨ̾ڡIUݩʦpUG

r:4
w:2
x:1

|ӨҤlӻA@ݩʬy-rwxr-xr--zɡAOXOHIڭ̥iHNLݦpUy-[rwx][r-x][r--]zTաAҥHƴNܦFy[4+2+1][4+0+1][4+0+0]z@y754zաIo˷|ܡHIOKIդ@UAUƬXG

-r-xr-xr-x
-rwxrw----

pGAiHXy555zPy760zAIANӷ|oIҥHApGAnN .bashrc ]wҦHiHŪܡANUFy chmod 777 .bashrc zaI𫟺ݭnSO`NOAq`ڭ̳|\ӤH]wIѩӤHw]OOb/home/userID/public_htmlUA /home/userID ݩʬydrwx------zڥN\HiJIҥHAA̤֭nNAؿ]w ydrwx--x--xz ~iHIM]iH]wydrwxr-xr-xzILij]wy777zI
@


---

• umask

OKI{bڭ̪DpإߩΪ̬Oܤ@ӥؿɮתݩʤFALAzDAإߤ@ӷsɮשΥؿɡALw]ݩʷ|OܡHINP umask FI umask ObdOH򥻤WA umask NOwyثeϥΪ̦bإɮשΥؿɭԪݩʹw]zApoγ]w umask OHLwHU觋ӫwG
ykG

[root @test root]# umask 0022 [root@vbird test]# umask 002   <==᭱ 3 ӼƦrI [root@vbird test]# umask 0002

G
d umask ƭȬJ umask YiAӳ]wOHSINO umask ᱵTӼƦrIpӫwOHDn٬O Linux ɮݩʡ]EݩʡA r, w, x ^AӥBOHƪ@YҪAӦUWhG
@
• YϥΪ̫إ߬yɮסzhw]ySi ( x ) ءzAYu rw oӶءA]NO̤j 666

--rw-rw-rw-
• YϥΪ̫إ߬yؿzAhѩ x PO_iHiJؿA]w]Ҧv}AY 777

drwxrwxrwx
@
umask wOyӹw]ȻݭnvIz] rBwBx OO 4B2B1 AҥHoI]NOAngvANOJ 2 AӦpGnŪvA]NO 4 AnŪPgvA]NO 6 AӭnPgJvA]NO 3 AoAѶܡHаݱzA 5 OHINOŪP檺vաIpGHWҤlӻܡA] umask 002 AҥH user, group èSQݩʡAL others ݩʳQF 2 ( ]NO w oݩ )AѩϥΪ̡G
@
• إɮ׮ɡG(-rw-rw-rw-) V (--------w-) ==> -rw-rw-r--
• إߥؿɡG(drwxrwxrwx) V (--------w-) ==> drwxrwxr-x
@
۫HܡHAunϥ touch test Mݬݳo test ɮݩʡANiHDFIpݧAoӨϥΪ̥ثe umask OHUF umask YiI@ݬݥG
@

[root@vbird test]# umask 0002 [root@vbird test]# touch test1 [root@vbird test]# mkdir test2 [root@vbird test]# ls -l -rw-rw-r--    1 root     root            0 Oct 22 00:00 test1 drwxrwxr-x    2 root     root         4096 Oct 22 00:00 test2/ o{FHI Test1 ݩʬ 666-002 = 664 ITܡHOITI test2 oӥؿOHNO 777-002 = 775 I]TI [root@vbird test]# umask 003 [root@vbird test]# touch test3 [root@vbird test]# mkdir test4 [root@vbird test]# ll -rw-rw-r--    1 root     root            0 Oct 22 00:03 test3 drwxrwxr--    2 root     root         4096 Oct 22 00:03 test4/ KIݩʤS𫍧@oIJӱV@UItest3 666-003 =663AoO@^ơHI 663 ӬO -rw-rw--wx ~ڡI|OWݩʡIIo̴NnSOLjդFIyɶqnHƦrۥ[աIzeyWDIAӭno˷Q(-rw-rw-rw-) - (--------wx)=-rw-rw-r--o˴NաIAѤFܡHnΤQi쪺ƦrIOܡAΤGiӺAoܡA rwx ӺI ^_^

@
ѤWҤlzӫܻNiHo{ umask γ~Iӳo umask iHb /etc/bashrc ̭iקIw]pUA root umask 022 Ӥ@ϥΪ̫h 002 A]igvZYA]w]|ovI~A] root nIҥHFwݨDAPsժgJݩʴNQFIoFwʤ]@w{ת^mI
@


---

• chattr

ykG

[root @test /root ]# chattr [+-=][ASacdistu] [ɮשΥؿW] ѼƻG +-=@GO [+ W[] [- ] [= ]w] ݩʪN A@@G]wF A oݩʮɡAoɮ(Υؿ)sɶ atime (access) NiQקA @@@ iקKҦpⴣqeϺ I/O ~po͡I S@@Goӥ\঳I sync \INO|NƦPBgJϺзIiHĪקKƬyI a@@G]w a AoɮױNuW[ơAӤRAu root ~]woݩʡC c@@Goݩʳ]wAN|۰ʪNɮסyYzAbŪɭԱN|۰ʸYXӡI @@ @ObxsɭԡAN|iYAxs]ݨӹjɮצGZΪI^ d@@G dump (ƥ){dzQ檺ɭԡA]w d ݩʱNiϸɮ(Υؿ)㦳 dump \ġI i@@Go i iNܼF`FILiH@ɮסyQRBWB]ws]LkgJηsWơIz @@@ tΦwʦ۷jUqI j@@Gϥ ext3 oɮרtή榡ɡA]w j ݩʱN|ɮצbgJɥOb journal I @@ @O filesystem ]wѼƬ data=journalled ɡAѩwg]wFxFAҥHoݩʵLġI s@@Gɮ׳]wF s ѼƮɡALN|QXoӵwЪŶC u@@GP s ۤϪAϥ u ӳ]wɮ׮ɡAhƤe٦sbϺФAiHϥΨ undeletion. dҡG [root @test /root]# chattr +i /etc/shadow<==IphLkʳoɮoI [root @test /root]# chattr -i /etc/shadow <==ѰݩʡI

G
ooӫOOnAרObtΪwʤWIѩoݩʬOêʽAҥHݭnH lsattr ~ݨݩI𫟺AӤH{̭n +i oݩʤFA]LiH@ɮ׵LkQʡAݭnjPtΦwHӻAuO۷nIY٦۷hݩʬOݭn root ~]wOI~ApGO log file oتnɡANݭn +a oӥiHW[A|QѼƤFIˡHܴΧaIӴnɪ{ɡAڭ̦AӲ@p]wLaI
@


---

• lsattr

ykG

[root @test /root ]# lsattr [-aR] ѼƻG -a@GNɪݩʤ]qXӡF -R@GsPlؿƤ]@֦CXӡI dҡG [root @test /root]# chattr +i .bash_logout [root @test /root]# lsattr -a  -------------- ./. -------------- ./.. ---i---------- ./.bash_logout -------------- ./.bash_profile -------------- ./.bashrc -------------- ./.emacs -------------- ./.screenrc

G
oӫObϥΤWnSOpߡAҦpGYѧA߱nAMN /etc/shadow oӭnKXOɮ׵L]w㦳 i ݩʡALFYzѤAAMnsWϥΪ̡Ao@LksWIOháA֥hN i ݩʮaI

ɮתjMiNF`FI]ڭ̱``ݭnDɮשb̡AҥHӽͤ@ͫjMaIb Linux U]۷ujMtIq` find ܱ`ΪI]t׺C~A]ܾ޵wСIq`ڭ̳Oϥ whereis Ϊ̬O locate ˬdApGu䤣FA~H find ӷjMIOH] whereis P locate OQθƮwӷjMơAҥH۷ֳtAӥBèSڪjMwСAٮɶաI

which   dݥiɮתm
whereis dɮתm
locate  tXƮwdɮצm
find    ڷjMwХhdɮצW

---

which

ykG

[root @test /root ]# which  [ɮצW] ѼƻG dҡG [root @test /root]# which passwd /usr/bin/passwd

G
which 򥻥\Oyǥ PATH oܼƪeAhӸ|MiɡzAҥH򥻪\byMzoI
@

---

whereis

ykG

[root @test /root ]# whereis [-bmsu] [ؿW] ѼƻG -b    :u binary ɮ -m    :ub manual |Uɮ -s    :u source ӷɮ -u    :SɪɮסI dҡG [root @test /root]# whereis passwd passwd: /usr/bin/passwd /etc/passwd /usr/share/man/man1/passwd.1.bz2 N passwd rɮשΥؿCXӡI [root @test /root]# whereis -b passwd passwd: /usr/bin/passwd /etc/passwd ȦCXbinary ɮסI [root @test /root]# whereis -m passwd passwd: /usr/share/man/man1/passwd.1.bz2 ȷjM man page ҦbؿI

G
pGϥ find ӳ·СAӥBɶΪܤjI]]pGAwФªܡAKKII^oӮɭ whereis N۷nΤFIt~A whereis iH[JѼƨӧMơAҦppGAOniɡ] binary ^[W -b NiHաIҦpWdҰw passwd o{ӻIpG[ѼƪܡANNҦƦCXoI whereis 쩳OϥΤNNOHjMt׷| find ֳohHI꨺]SIoO] Linux tη|NtΤҦɮ׳Ob@ӸƮwɮ׸̭Aӷϥ whereis Ϊ̬OUn locate ɡA|HƮwɮתeǡA]AɫAٷ|o{ϥγoӰɮɡA|wgQɮסIoNO]LO@ӡyƮwzɮקrIt~A򥻤W Linux Cѷ|w Linux Di updatedb ]NO@ӸƮwɮoI^ʧ@AAiHb /etc/cron.weekly/slocate.cron oɮקIMA]iHϥ /usr/bin/updatedb ӧsƮwɮשOI
@

---

locate

ykG

[root @test /root ]# locate [ؿW] ѼƻG dҡG [root @test /root]# locate root KK@j root rɮ׳XӤF @_@ [root @test /root]# updatedb        <==ߨsƮw

G
locate ϥΤ觋N²FIJAn䪺ɦWYiIOAoӪF٬OϥΤWIOHz|o{ϥ locate ӴMƪɭԯSO֡AoO] locate M䪺ƬOѡywإߪƮw /var/lib/slocatez̭ƩҷjM쪺AҥHΪbhwзsơAIMOܧֳtoI򦳤򭭨OHNO]LOgѸƮwӷjMAӸƮwإ߹w]ObC§@AҥHzsإ߰_ӪɮסAo٦bƮwsejMɮסA locate |iDzy䤣IzI]nsƮwrI
@
ڨ쩳nإ߭ǸƮwOHO_nإߡHGݭnAoӮɭԡAAiHۤvܻݭnإɮ׸ƮwؿOIb /etc/updatedb.conf oӤYi]wFI
@

[root @test root]# more /etc/updatedb.conf ## Linux-Mandrake configuration. # ѦB}ld߸ơAMOѮڥؿաIҥHJ / Yi FROM="/" # ǥؿQnإɮ׷jMơAINOǤnƹI # ѰOܡAOo^W@hݬݤeANDp]wFI PRUNEPATHS="/proc,/tmp,/var/tmp,/usr/tmp,/net,/afs,/mnt" # w #   0 NwAtפWֳtAwF #   1 Ұʦw²AoOtΪw]ȡF SECURITY="1" # dߪɭԬO_nѿùXHMnA_hh·? VERBOSE="NO" # ƮwҦbBIoOw]ȡAnHNʡA_h|䤣I DATABASE="/var/lib/slocate/slocate.db" # ɮרtΧڭ̤]jMإߡHNOаաBD Linux ɮ׮榡աA # ڭ̳nijMTإ߰աI PRUNEFS="nfs,smbfs,ncpfs,proc,devpts,supermount,vfat,iso9660,udf,usbdevfs,devfs"

@

---

find

ykG

[root @test /root ]# find [|] [Ѽ] ѼƻG 1. ɶG    -atime n    :b n*24 pɤe@ѤQ access YsLɮצCXӡI    -ctime n    :b n*24 pɤe@ѤQ changed YܡBsWɮשΥؿLX    -mtime n    :b n*24 pɤe@ѤQ modified YקLɮצLX    -newer file : file ٭nsɮ״NCXӡI 2. ϥΦW١G    -gid n      :M s ID n ɮ    -group name :MsզW٬ name ɮ    -uid n      :M֦ ID n ɮ    -user name  :MϥΪ̦W٬ name ɮ    -name file  :MɦW file ɮצW١]iHϥθUΦr^    -type type  :Mɮݩʬ type ɮסAtype ]tF b, c, d, p, l, sA                 oǻPe@ݩʬۦPIҦp l Link d |NI dҡG [root @test /root]# find / -name testing            <==MɦW testing  [root @test /root]# find / -name 'test*'       <==MɦW]t test I [root @test /root]# find . -ctime 1                 <==MثeؿU@ѫesWؿɮ [root @test /root]# find /home/test -newer .bashrc  <==M /home/test ؿU .bashrc ٭nsɮ [root @test /root]# find /home -user test       <==M /home U֦̬ test ɮ [root @test /root]# find /dev -type b               <==M /dev oӥؿUAɮݩʬ b ɮ

G
pGAnM@ɮתܡAϥ find |O@ӤDNILiHھڤPѼƨӵɮתjM\IҦpAnM@ɦW httpd.conf ɮסAADLӬOb /etc UANiHϥΡy find /etc -name httpd.conf zPIpGAOo@ɮɦW]tF httpd AODWHIANθUΦr aApWHGy find /etc -name '*httpd*' zNiNɦWt httpd ɮ׳CXoILAѩ find bMƪɫ۷ӵwСIҥHSƱnϥ find աIΪOiHNINO whereis P locate oII

• SUID P SGIDG

Ao̤eAӥ@U UID (user ID)P GID (Groupt ID)I򥻤WA Linux {obuO@ƦrӤwIӥѩڭ̨CɮפPɧtyϥΪ̡zPyϥΪ̸sաzݩʡA]ANҿת UID P GID oI UID Nڭ̪ϥΪ̡yNz GID hOsժyNzCAiHϥΡy more /etc/passwd zoӫOӬݤ@UAtηҦbAMA|`NC檺ĤTB|]H : j^ƦrAӴNO UID P GID FAz|`N쪺OA root UID P GID O 0 I]AAإߤF@ӱbAӧANӱb UID P GID אּsAIӱbϥΪ̴N㦳 root oI
@
򤰻O SUID P SGID OHIbeڭ̥ӥH@먭ϥΪ ( ٰOow˪ɭԴgW[@ test b@먭ϥΪ̶ܡHաIΥLIMOHbLWU [Alt] + [Ctrl] + [F2] ĤGӲ׺ݾrI) test nJAAӬݤ@ɮתeG
@

[test@test test]$ ls -l /usr/bin/passwd  -r-s--x--x    1 root     root        13476 Aug  7  2001 /usr/bin/passwd

@
ݨF /usr/bin/passwd ɮתeݩʤFܡH| s ݩʦb쥻 x rIHӴNOҿת SUID FIpGOy -r-xr-s--x zɡA s Nҿת SGID FI
@
y@ɮר㦳 SUID ɭԡAP other sը㦳i檺vA others sհӵ{ɭԡA other N֦ɮת owner vIzC
@@

[test@test test]$ ls -l /usr/bin/passwd /etc/shadow  -r-s--x--x    1 root     root        13476 Aug  7  2001 /usr/bin/passwd  -rw-------    1 root     root         2423 Jun 25 14:29 /etc/shadow

@
ڭ̥HbKXɨӻnFI`NWdoIiHݨ쪺OA /etc/shadow vOyu root ~szIA||ıoܩ_ǡHڪ@ϥΪ̥iHۤvקKXrI藍HקKX@w /etc/shadow oɮצA^ƧrIHϥΪ̬Opק /etc/shadow oɮתOHISINOϥ SUID \աIWҤlFA /usr/bin/passwd oɮר㦳 SUID ݩʡAϥΪ̨ϥ /usr/bin/passwd oӰɮɡAb pass word ק諸N㦳 /usr/bin/passwd oɮת֦ root voIҥHAҥH@ϥΪ̰ passwd ɭԡAN㦳 root vAҥHL̤]iH /etc/shadow eoIѦ]iHDAѩo Set UID ( SUID ) Dn\ObyYɮװ檺㦳ɮ׾֦̪vzA]A s NONW쪺 x oӥi檺moIU@ɮרèS x ݩʩOHIݪnIɮתݩʴN|Npg s ܦjg S աI ( o̧YϼȮɤAѤ]SYAL@}lA^Ӭݤ@ݡAAN|AѰաI )
@
LAѦ]D SUID P SGID DҦbASINOӤwFIpGA@ɮר㦳 root vA}ҤF SUID ɭԡAKKIA@FII]WAbܧ@ɮצ㦳 SUID SGID pɡAnSOpߩOIDGIH
@
• Sticky bitG

OKIۤUӡAڭ̭nӬݤ@UAJM SUID P SGID A򬰤Sb̥X{ s N x OHIoMSnաI]Oݩ others vAAɮצpGOHҥi檺ܡA򥻨ӥL̴N㦳vաIF٭n]w s ݩʡIHLAo̫out@ݩʥX{FANO Sticky bit ݩ ( t ) Ioݩʪ̤jγBby㦳 sticky bit ݩʪӡؿUɮסAɮשΥؿuɮ׾֦̤ root ~vORIzoˬO_iHAѤFOHKKISIbڭ̨tθ̭ӴNw]@ӰաINO /tmp oӥؿI
@@

[test@test test]$ ls -l /  drwxrwxrwt    2 root     root         4096 Jul 18 13:08 tmp

@
pAo{FaIMӥؿ㦳ҦHҥiŪgvAOT@ t X{FANOҿת sticky bit oIbӥؿ̭MAiHإ߻PקɮסAOoȯRۤvإߪɮשOIDAO root IAiHo˸ոլoG
@
1. H root nJtΡAåBiJ /tmp F
2. touch testAåB test v 777 F
3. H@ϥΪ̵nJAöiJ /tmpF
4. էR test oɮסI
@
pIHo{FaII
@
• SUID, SGID, Sticky bit ]wkG

eйL SUID P SGID \Ap}ɮרϦ㦳 SUID P SGID vOHIoNݭn𫍧ƦrvkFI{bAӤwgDƦrAӧv觋yTӼƦrzզXApGboTӼƦreA[W@ӼƦrܡA̫eƦrNNoXݩʤFI ( Gq`ڭ̨ϥ chmod xyz filename 觋ӳ]w filename ݩʮɡAhO]S SUID, SGID Sticky bit աI )
@
• 4 SUID
• 2 SGID
• 1 Sticky bit
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]nN@ɮݩʧאּy-rwsr-xr-xzɡAѩ s bϥΪvAҥHO SUID A]Ab 755 e٭n[W 4 A]NOGy chmod 4755 filename zӳ]wI~A٦j S Pj T ͳIѦҩUdҰաI
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[root@test tmp]# touch test [root@test tmp]# ll total 0 -rw-r--r--    1 root     root            0 Feb  6 23:08 test [root@test tmp]# chmod 4755 test [root@vbird tmp]# ll total 0 -rwsr-xr-x    1 root     root            0 Feb  6 23:08 test* [root@test tmp]# chmod 6755 test [root@test tmp]# ll total 0 -rwsr-sr-x    1 root     root            0 Feb  6 23:08 test* [root@test tmp]# chmod 1755 test [root@test tmp]# ll total 0 -rwxr-xr-t    1 root     root            0 Feb  6 23:08 test* WTӨҤlӳܦnڡINON x H s Ϊ̬O t ӨNNOFI]NOO SUID, SGID sticky bit ]wkաI [root@test tmp]# chmod 7666 test [root@test tmp]# ll total 0 -rwSrwSrwT    1 root     root            0 Feb  6 23:08 test oӨҤlNnSOp߰աI|X{jg S P T OHOpgܡH] s P t ON x oӰѼƪAOASo{Aڭ̬OUF 7666 I]NOA user, group H others S x oӥi檺лx ( ] 666 I )AҥHAo S, T NNOyŪzաI򻡡H SUID Oܡyɮצb檺ɭԡA㦳ɮ׾֦̪vzAOɮ׾֦̳LkFĄӪvLHϥΡHMNOŪաI ^_^

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• file

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[root @test /root ]# file [ɦW]  ѼƻG  dҡG  [root @test /root]# file ~/.bashrc  /root/.bashrc: ASCII text  <==ܳoɮ׬O ASCII ¤r  [root @test /root]# file /usr/bin/passwd /usr/bin/passwd: setuid ELF 32-bit LSB executable, Intel 80386, version 1, dynamically linked (uses shared libs), stripped KI٥iHݨO_㦳 SUID vOI

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file oӫO]ZnΪAiHΨӬdݳoɮתAҦp ASCII 榡ɡAΪ̬O binary ɮ׵A٥iHΨ[ɮ׬O_Q[J SUID TIåBA]PɴѤFO_ϥΰʺA祃wTI۷nΡI

• O|P۹|

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|gk / }lgAܩ۹|h / }lgI

• p@ӥؿW١HҦp /home/test ܬ /home/test2

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mv /home/test /home/test2

• PATH oܼƪNqH

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oӬOΨӫwɰ檺ɭԡAɮ׷jMؿ|C

• umask γBPuIH

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umask iH@ݩʡA]AAwq umask UtΪwA]LiHΨӫإ߹w]ؿɮתvC

• @ӨϥΪ̪ umask O 033 P 044 Lҫإߪɮ׻PؿvH

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b umask 033 ɡAhw]O group P other w(2)x(1) vA]vNyɮ Vrw-r--r-- A ؿ drwxr--r-- zӷ umask 044 ɡAh r ݩʡA]Nyɮ -rw--w--w-Aؿ drwx-wx-wxz

• O SUID H

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@ӫO㦳 SUID \ɡAhLHϥγoӫOɡAӵ{DZN㦳O֦̪vC

• ڭnd /usr/bin/passwd oɮת@ݩʮɡAiHϥΤOӬdߡH

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ls Val, file, lsattr

• ե find Xثe linux tΤAҦ㦳 SUID ɮצǡH

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find / -type f Vperm V04000 -print