CӤHΦhΤֳ@Ǭ|Ϊ̬Ou@Au@OҦʪAҦpC~@[~BCӤ@u@iBCg@\|BCѻݭndFu@hO{ɵoͪAҦpn`qxӳXAݭnAdzƺtIΦbͬWAҦpC~RHͤBCѪ_ɮɶB٦oʪqj]ڵn[F^oCoǤu@iH٬ҦʩROAӳoǤu@ Linux ]iHzAҦpGC@ѦW 8:00 nAsWTAñҰʭ֨ӳA_ɡFӤ 12:00 Ʊ Linux iHo@ʫHAlHcAAiHhY\FFt~AbC~ARHͤ骺e@ѡAoʫHAAHKѰOo򭫭n@ѡC

qWiHܲMo{ؤu@Ƶ{觋G

• @جOҦʪANOCj@wgnӿ쪺ƶF
• @جOoʪANOoHNS@ء]qj....^

b Linux UpFoӥ\OHINoϥ at P crontab oӦnFoI

• at G oӤu@Ȱ@Nq Linux tΤƵ{F
• crontab G oӤu@NҦʪ@UhI

Uڭ̥ӽͤ@ Linux tΨ쩳bƱA򦳭Yzhu@Ƶ{bu@OHMA^ӽͤ@ at P crontab oӦnFI

nFAAۤvҦʩROnӧ@rIHLinux u@ih۩OIѫe쪺Xg峹Aڭ̪DLinux bIUu@iOܦhAרO}񪺱pUAإ߻PsuBMySQL ƮwYɧsBHΤ@ǨҦ檺tΫOAҦpO骺u@CѩҦ檺u@D`hAbiCѳn޲zӤʿJaIҥH~|إ߳oӤu@Ƶ{ݨDI򥻹w]u@UoǡG

• iƽ ( log rotate )GoӨBJnFIרOb log file ﶵIѩnɮ׷|VӶVjAҥHݭnAɾAqNnɳƥAåHs}ɮרӶiOAoˮIJv|nA]Nݭnϥ log rotate աItιw]nu@@F

• rpm ƮwإGM RPM Ʈw|bAH RPM wˤYs RPM ƮwhAOO||AҥHtΤ]|]wCj̬qɶ۰ʪ`tΤW RPM Ʈwӫظm@fF

• إ locate ƮwGO_ٰOoϥ locate oӫOɡAjMt׶W֡IO] Linux tΤWNɮ׻P|ObƮw̭FIҥHϥ locate ɭԡAKKIVƮwh ( /var/lib/slocate/slocate.db ) A·ЪOoɮתsOCѤ@IҥHAѧsɮסAϥ locate Ϧӥi|䤣....

• i{ǪRGCj̬qɶ|i{ǪRApGo{͵{ǪɭԡAN|NLRhIHOO骺u@OI

• nɵGoӪFOb Red Hat 7.1 H~X{FAӤӦnΤFAҥHQª Red Hat ̭hϥΡI򥻤WNORnɰաIMڥHѪRDɡAH@DwʡIo~p̤]ۤvgF@²RɮסAıonδNOFI

• ƮwG򥻤WNO tripwire oӮMաIiHΨӤR̪QʹLɮפeIZ@ӵ{IŤ]ӪݡC

Linux w]Ҧu@ܤִNoǤFAA[WzVO Linux iu@Ƶ{]pAKKICѪu@qiO۷jOI

pGȭn@u@ANϥ at oӫOaIoӫONO atd oӪAȰաIҥHаOo@wnҰʳoӪAIpGOb Red Hat tΤUAiHϥΡG

1. ntsysv
2. atd
3. U OK I

pGOb Mandrake tΤUAiHϥΡG

1. chkconfig --add atd
2. chkconfig --list

WoӫOiHd atd b run-level TpAO_|b}ɭԳQҰʡI

򥻤WA atd Ow]}ҪApGzSʹLtιw]ȪܡAWʧ@NݭnoIUF at oӰʧ@|Nu@Ƶ{gJ /var/spool/at oӥؿUOIMᵥݨtαNoI~Ao at OMw]OҦHiAOiHg root WdӭϥΪHfCkP /etc/hosts.allow(deny) Aϥ /etc/at.allow(deny) oɮרӭG

• ϥΪ̭zGϥΪ̰ at ɡAtη|

@
1. M /etc/at.allow oɮסAgboɮפϥΪ̤~ϥ at ASboɮפϥΪ̫hϥ at ( YϨSgb at.deny   )F
2. pGS /etc/at.allow NM /etc/at.deny oɮסAYgbo at.deny ϥΪ̫hϥ at AӨSbo at.deny ɮפϥΪ̡ANiHϥ at F
3. pGɮ׳sbAu root iHϥ at oӫOC

• Linux w]pUAu /etc/at.deny oɮסABoɮתeťժAѩ󤺮eSϥΪ̡AҥHMyҦHiHϥ at z

• pGQnYӨϥΪ̨ϥ at ɡANӨϥΪ̱bg /etc/at.deny oɮפYiC

nFIڭ̨ӽͤ@ at ykaI
 

[test @test test]# at [-m] TIME@@@@(UFu@O) [test @test test]# atq@@@@@@@@ (dݥثeu@Ƶ{) [test @test test]# atrm [jobnumber]@@(RƵ{) ѼƻG -m    G at ҳWdu@Ƶ{ɡANùXG mail UFOϥΪ TIME  Gɶ榡AUXӡG @@@HH:MM YYYY-MM-DD@@@@@@@@@@@ @ex> 04:00 2002-05-30 (TQ|I) @@@HH[pm;am] + number [hours;days;weeks]@@ex> 4pm + 3 days (bL 3 ѪU 4 I) @@@HH:MM@@@@@@@@@@@@@@@@@@ex> 12:00 (Ѫ 12 I) @@@HH[pm;am] [Month] [Day]@@@@@@@@@ex> 1pm May 30 jobnumberGC@ at u@Ƶ{sƪǡIoӧYOI dҡG [test @test test]# at 5pm   <==bѪ 5pm ApGѤwL 5 IhѰF warning: commands will be executed using (in order) a) $SHELL b) login shell c) /bin/sh at> mail -s test test < /home/test/.bashrc <==oNOڪu@I at> <EOT> <==o̬OU [Ctrl] + D NiH}FI job 8 at 2002-05-30 17:00  <==o̷|iDAoӤu@X 8 A檺᭱ҥܡC [test @test test]# atq   <==s@UA(test)ثeh֤u@H 5       2002-05-30 12:00 a test 8       2002-05-30 17:00 a rest [test @test test]# atrm 5<==R 5 u@ [test @test test]# atq 8       2002-05-30 17:00 a rest

Ъ`NIb at UFAKiJOCUFҦIbo̧AiHƪJOAO}ɭԽФUFy [Ctrl] + D zNiH}FI}Atη|iDAoӤu@Ƶ{XPϥΪ̬O֡II²aI

oӴ`ҦʩRONO cron oӪAȰ (crond)IAUF crontab OA|NAROgJ /var/spool/cronoӥؿIҦp test UFFL crontab ROAN|۰ʲ /var/spool/cron/test oɮסIyЪ`NAoɮפઽsIzM檺OO|mb /var/log/cron oɮפIҥHAypGz Linux tΤDO_Q차JIɡAiHjM@U /var/log/cron oӰOסAݬݦSQdHz

nFIڭ̨Ӭݤ@U crontab OykaI
 

[test @test test]# crontab [-u user] [-l | -e | -r] ѼƻG -u user Gu root UFѼơAνsĶLϥΪ̪ crontab e -l      GCX crontab e -e      Gs crontab e -r      GR crontab e dҡG @ϥΪ test nbCѪ 12:00 oHۤvG [test @test test]# crontab -e <==ۤvsۤv crontab e iJ crontab s褺eAϥ vi I 0 12 * * * mail test < /home/test/test.txt ɤg |========OC===============|

WҤlOGpAݭnbCѪ 12:00 o@ʫHAۤvAӥBHewggnFAn˧@OHӥBAt@Ӱ]OAAb Linux Server vȤ@ϥΪ̡AäO root ]޲z^An˳]wAҦʩROOHINϥ crontab oӫOaIAuny crontab -e zNiHiJ vi seӽsAҦʩROI

bWҤlAJ crontab -e ɡA|X{@ vi eAMAb vi eJW@rA :wq xs}IYisIeaIW@rNNqOHAiHݨAbuROe]NO mail test < /home/test/test.txt ^`@ӼƦrAoӼƦrONG

@@]0-59^
pɡ@]0-23^
@]1-31^
@]1-12^
g@@]0-6^

ƦrNNq		p			g
d	0-59	0-23	1-31	1-12	0-6 (0P)

t~ApGOy   zɭԡANҦƦrAΪNCҥHAANiHDڤW@gNqFINOyצBBPX 12 I 0 ɡA mail test < /home/test/test.txt oөROzI٤AѡHSYAڭ̳o̧@XӨҤlI
 

D@GpAkBͥͤO 5 2 AAQnb 5 1 骺 23:59 o@ʫHLA @@@@oʫHewggb /home/test/lover.txt F [test @test test]# crontab -e 59 23 1 5 * mail pigpp < /home/test/lover.txt

˪ܡAC~ pigpp |AoʫHI]MoAHeNnC~ܤ@ܰաI^
 

DGGpACjnh check A@ӦW test.sh 妸ɤ@AhG [test @test test]# crontab -e 59 23 1 5 * mail pigpp < /home/test/lover.txt  <==𫍧ӫO٦sbI */5 * * * * /home/test/test.sh  <==s[J@ӱƵ{I

`NI crontab CӤHu@ɮסANOb /var/spool/cron ̭ɮװաI٦ƭn`N@UG

(1) O|̦nOUF|Aoˤ|䤣檺ɮ׳F
(2) Ĥ@ӼƦr */5 ܡyC@zNI

DTGpAC§PU 4:30 niDBͬP|nѰOAhG [test @test test]# crontab -e 59 23 1 5 * mail pigpp < /home/test/lover.txt  */5 * * * * /home/test/test.sh 30 16 * * 5 mail frend@test.domain.name < /home/test/frend.txt <==s[JI

Io˫²aIpNiHFzһݭnҦʤu@Ƶ{woI

nFIڭ̭npӬdݨϥΪ̥ثe crontab u@Ƶ{OH
 

[test @test test]# crontab -l <==o -l O L pg # DO NOT EDIT THIS FILE - edit the master and reinstall. # (/tmp/crontab.27683 installed on Thu May 30 13:38:38 2002) # (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $) 59 23 1 5 * mail pigpp < /home/test/lover.txt */5 * * * * /home/test/test.sh 30 16 * * 5 mail frend@test.domain.name < /home/test/frend.txt

IoܪeNO /var/spool/cron/test ɮתeաIpRƵ{OH
 

[test @test test]# crontab -r [test @test test]# crontab -l no crontab for test

ݨFܡH crontab yӤeFIzҥHЪ`NGypGuOnRY crontab u@ءAШϥ crontab -e ӭssYiIzpGϥ -r ѼơAO|NҦ crontab ƤeRIdU`NFI

oӡy crontab -e zOwϥΪ̪ cron ӳ]pApGOytΪҦʥȡzɡAӫOHO_٬OݭnH crontab -e Ӻ޲zAҦʩROOHMݭnAAuns /etc/crontaboɮ״NiHաI@IݭnSO`NINO crontab -e o crontab O /usr/bin/crontab oӰɡAO /etc/crontab iO@ӡy¤rɡzIAiH root s@Uoɮ׭I

򥻤WA cron oӪAȪ̧COyzAҥHy cron |ChŪ@ /etc/crontab P /var/spool/cron ̭ƤezA]AunAs觹 /etc/crontab oɮסAåBNLxsAI crontab ]wN۰ʪ|ӰFI

`NGb Linux U crontab |۰ʪڭ̨CsŪ@ /etc/crontab Ҧu@ƶAOYǭ]Ϊ̬OL Unix tΤAѩ crontab OŪOAҥHbAק粒 /etc/crontab Aiä|WAoӮɭԽЭsҰ crond oӪAȧaI

/etc/rc.d/init.d/crond restart

nFAڭ̨Ӭݬ /etc/crontab oɮתeaG
 

[root@test /root]# vi /etc/crontab SHELL=/bin/bash PATH=/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root HOME=/ # run-parts 01  * * * * root    run-parts /etc/cron.hourly   <==Cpɰ檺u@ 02  4 * * * root    run-parts /etc/cron.daily   <==C 檺u@ 22  4 * * 0 root    run-parts /etc/cron.weekly  <==CP檺u@ 42  4 1 * * root    run-parts /etc/cron.monthly  <==CӤ檺u@ ɤg ϥΪ    Ѽ     O

ݨoɮתeAjNAѤFaIASIoɮ׻PNڭ̤UF crontab -e eXG@Ҥ@ˡIuOXӦa褣ӬۦPG

• MAILTO=rootGOA /etc/crontab oɮפҦʩROoͿ~ɡA|N~TΪ̬OùܪTǵ֡Hѩ root õLkbΤݤHA]Aڳq`No e-mail 令ۤvbAnHAѨtΪpI

• 01 * * * * root run-parts /etc/cron.hourlyGbѲŸ #run-parts o@H᪺ROAڭ̥iHo{AӼƦr᭱O root ISAo@NOy檺hŬ root zMoAA]iHNo@gLI run-parts N᭱ /etc/cron.hourly Oy@ӥؿ]/etc/cron.hourly^ҦizAo]NOACӤpɪ 01 Atη|H root hŪϥΪ̥h /etc/cron.hourly oӥؿUҦiH檺ɮI᭱T]ONIAiH /etc/ UhݬݡAtΥӴNw]Fo|ӥؿFIAiHNCѻݭn檺ROg /etc/cron.daily YiA٤ݭnϥΨ crontab -e {OIKaI

`NG򥻤W /etc/crontab Y䴩ؤUFO觋A@جOH OA UFA@ثhOHyؿWzӤUFF

• OAG

01 * * * * test mail -s test test < /home/test/test.txt
ϥΪ̬O test, BbCӤpɰ@O mail ...

• ؿWG

*/5 * * * * root run-parts /root/runcron
إߤ@ /root/runcron ؿANnCj檺yiɡzgӥؿUANiHtΨC@ӥؿUҦiɡC

o˴NiHo run-parts ηNFaI~AP crontab -e W̤ۦPNOhF@ӡyϥΪ̼hšzAq`ڭ̳OH root רӳWҦʩROAO`ݭn root OaINiHϥγoӼhŨӳWdӵ{ǪϥΪݩoI

nIA{bjAѤFo@өNNaIOKI]A{bn@@ӥؿAtΥiHC 2 hoӥؿUҦiH檺ɮסAAiHgUpUo@b /etc/crontab G

*/2 * * * * root run-parts /etc/cron.min

MoA /etc/cron.min oӥؿOݭnsbIpGڻݭn檺O@ӡy{zӤwAݭnΨ@ӥؿOHӦpOnHҦpbyqɡAڭ̧ƱCR@AiHo˼gG

*/5 * * * * root /usr/local/mrtg-2/bin/mrtg /usr/local/apache/htdocs/mrtg/net/mrtg.cfg

SF run-parts NONy@ɮסzNաI

pIHإߨҦʩRO²aIpGAOtκ޲zܡAק /etc/crontab oɮקYiISKQASK޲zOI

• 귽tG

jqϥ crontab ɭԡA`O|DoͪAYDNOytθ귽tzDAHڪtάҡA VBird yqTA]AG

• yq
• ϰ줺L PC yq
• CPU ϥβv
• RAM ϥβv
• uWHƧYɰ

pGCӬy{bP@ӮɶҰʪܡAIbYӮɬqɡAڪtη|ܪ۷cAҥHAoӮɭԴNnO]wաIڥiHo˰G
 

[root@test /root]# vi /etc/crontab 1,6,11,16,21,26,31,36,41,46,51,56 * * * * root ........  <== .. NAO 2,7,12,17,22,27,32,37,42,47,52,57 * * * * root ........ 3,8,13,18,23,28,33,38,43,48,53,58 * * * * root ........ 4,9,14,19,24,29,34,39,44,49,54,59 * * * * root ........

ݨFSHӡy , zjɭԡAЪ`NAnťզrI]s򪺷N^p@ӡAhiHNCu@y{ObPɨӤu@IhiHtΪZI

• nXG

t~@ӧxZoͦby榨GΪ̬O檺ؤXƮɡAӸƱN| mail MAILTO ]wbzAnաA@ӱƵ{@X]Ҧp DNS tηAY DNS WhDAAN|@~TI^HIٰOo BASH P Shell scripts @aIHHyROɦVzNXGX /dev/null oөUNnFI

• wG

ܦhɭԳQӤJ차OHҦRO觋ӤJAҥHiHǥˬd /var/log/cron eӵO_yDz]w cron QFHzoӮɭԴNݭnpߤ@IoI

• Ѱ]ڦ@ӫO{AW٬G ping.sh oɦWIڷQntΨCToɮפ@AOoɮ׷|ܦhTܥXӡAҥHڪ root bCѳ|th|ʦhʪHAOHNth֭nƱFIаӫ]wnOH

G
oӯAΩROɦVDAڭ̥iHNLɤJɮשΪ̪IpGӰTnܡANHApGTܭnܡA~NLOdUӡI]ѳoөROnAҥHNL󱼡I]AiHo˼gG
*/5 * * * * root /usr/local/ping.sh > /dev/null 2>&1