Linuxใฎcronใฎ่ชญใฟใปๆธใๆนใป่จญๅฎๆนๆณใซใคใใฆใพใจใใพใใใ
cronใฎไฝฟใๆน
cron(ใฏใญใณ)ใฏใๅฎๆ็ใซใธใงใใๅฎ่กใใๆฉ่ฝใงใใ
cronใฏใใcrondใใผใขใณใใจใcrontab(ๅฎ่กๅ
ๅฎนใใใณๅฎ่ก้ ปๅบฆใ่จ่ฟฐใใใใผใใซ)ใใงๆงๆใใใพใใ
ใcrondใใผใขใณใใฏใทในใใ ่ตทๅๆใซinitใใญใปในใซใใฃใฆ่ตทๅใใใใใฎๅพใฏๅฎๆ็ใซcrontabใใใงใใฏใใไฝใๅฎ่กใใใๅคๆญใใพใใ
ไพใใฐ
ใ3ๅ้ใซ1ๅใใใใฎใใญใฐใฉใ ใ่ชๅใงๅฎ่กใใใ
ใๆฏๆฅ12ๆใซใใใใฎใใญใฐใฉใ ใ่ชๅใงๅฎ่กใใใ
ใจใใฃใใใใซใๅฎ่กใใ้ ปๅบฆใ็ดฐใใ่ชฟๆดใงใใพใใ
cronใฏใๆใ็ญใ้ ปๅบฆใง1ๅๆฏใซใธใงใใๅฎ่กใงใใพใใ
cronใธใงใใฎ่จญๅฎใใกใคใซใ/etc/crontabใใฏrootใฆใผใถใผใฎใฟไฟฎๆญฃๅฏ่ฝใงใใ
ใพใใใใฎใใกใคใซใซใฏใไปฅไธใฎใใใช่กใ่จ่ผใใใฆใใพใ:
# vi /etc/crontab SHELL=/bin/bash PATH=/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root HOME=/ # For details see man 4 crontabs # Example of job definition: # .---------------- minute (0 - 59) # | .------------- hour (0 - 23) # | | .---------- day of month (1 - 31) # | | | .------- month (1 - 12) OR jan,feb,mar,apr ... # | | | | .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat # | | | | | # * * * * * user command to be executed
ๆๅใฎ3 ่กใฏใใฟในใฏใฎๅฎ่ก็ฐๅขใ่จญๅฎใใๅคๆฐใๅฎ็พฉใใพใใ
้ ็ฎ | ๆฆ่ฆ |
---|---|
SHELL | ใธใงใใฎๅฎ่กใซไฝฟ็จใใใทใงใซ็ฐๅข๏ผไธ่จใฎไพใงใฏBash ใทใงใซ๏ผ |
PATH | ๅฎ่กๅฏ่ฝใชใใญใฐใฉใ ใธใฎใใน |
MAILTO | ใกใผใซใงcronใธใงใใฎๅบๅใๅไฟกใใใฆใผใถใผๅใๅฎ็พฉใใใฆใใชใๅ ดๅ(MAILTO=)ใใกใผใซใฏ้ไฟกใใใพใใใ |
ๆฎใใฎ่กใฏใในใฑใธใฅใผใซใใใฆใใใธใงใใฎ่จญๅฎใไปฅไธใฎๆธๅผใง่จ่ผใใฆใใพใใ
ๆธๅผ
minute hour day month day of week user command
ใๅ ๆ ๆฅ ๆ ๆๆฅ <ๅฎ่กใณใใณใ>ใใจใชใใพใใ
้ ็ฎ | ๆฆ่ฆ |
---|---|
minute | ๅฎ่กใใๅใ0ใ59ใพใงใฎไปปๆใฎๆดๆฐใงๆๅฎ |
hour | ๅฎ่กใใๆ้ใ0ใ23ใพใงใฎไปปๆใฎๆดๆฐใงๆๅฎ |
day | ๅฎ่กใใๆฅใ1ใ31ใพใงใฎไปปๆใฎๆดๆฐใงๆๅฎ |
month | ๅฎ่กใใๆใ1ใ12 ใพใงใฎไปปๆใฎๆดๆฐใงๆๅฎ |
day of week | ๅฎ่กใใๆๆฅใ0ใ7 ใพใงใฎไปปๆใฎๆดๆฐใ(0ใจ7ใฏๆฅๆๆฅใ1ใฏๆๆๆฅใ2ใฏ็ซๆๆฅใ3ใฏๆฐดๆๆฅใ4ใฏๆจๆๆฅใ5ใฏ้ๆๆฅใ6ใฏๅๆๆฅใๆใ) |
user | ใธใงใใๅฎ่กใใใใขใซใฆใณใใฎใฆใผใถใผๅใๆๅฎ |
command | ๅฎ่กใใใณใใณใ |
- ใขในใฟใชในใฏ (/*)
- ๅ จใฆใฎๆๅนใชๅคใๆๅฎใงใใพใใไพใใฐใdayใซใขในใฟใชในใฏ (*) ใๆๅฎใใใจใๆฏๆฅๅฎ่กใใใพใใ
- ใใคใใณ (-)
- ๆดๆฐใฎ็ฏๅฒใๆๅฎใงใใพใใไพใใฐใ1-3ใฏๆดๆฐ 1ใ2ใ3ใๆใใพใใ
- ใซใณใ (,)
- ใซใณใ (,) ใงๅบๅใใใๅคใฏใไธ่ฆงใๆๅฎใใพใใไพใใฐใใ1, 3, 4ใใฏใใใ3ใคใฎๅคใฎๆดๆฐใๆใใพใใ
- ในใฉใใทใฅ (/)
- ในใฉใใทใฅ (/)ใงในใใใๅคใๆๅฎใงใใพใใ็ฏๅฒใฎๅพใซใ/ใใไปใใใจใใใฎ็ฏๅฒๅ ใงๆๅฎใใๆดๆฐใฎๅคใในใญใใใงใใพใใไพใใฐใminuteใงใ0-59/5ใ ใจๆๅฎใใใจใ0ใ59ๅใฎ้ใง5ๅใใจใซๅฎ่กใงใใพใใ
- ใใใทใฅ่จๅท (#)
- ใณใกใณใ่กใ
crontabใฎไฝฟใๆน
rootไปฅๅคใฎใฆใผใถใผใฏใcrontabใไฝฟ็จใใฆcronใฟในใฏใ่จญๅฎใใพใใ
ใฆใผใถใผใๅฎ็พฉใใcrontabใ/var/spool/cron/ใใใฃใฌใฏใใชใซๆ ผ็ดใใใพใใ
ใใใฆใcronta ใไฝๆใใใฆใผใถใผๅใงๅฎ่กใงใใพใใcrontabใฎไฝฟใๆนใฏไปฅไธใฎใจใใใงใใ
โไปฅไธใฎใณใใณใใๅฎ่กใใพใใ
$ crontab -e
โใVISUALใใใใใฏใEDITORใ็ฐๅขๅคๆฐใงๆๅฎใใใฆใใใจใใฃใฟใผใงcrontabใ็ทจ้ใใพใใ
โ crontabใๅคๆดใใฆไฟๅญใใใจใใ/var/spool/cron/usernameใใซๆธใ่พผใพใใพใใ
โ ไปฅไธใฎใณใใณใใงcrontabใฎๅ ๅฎนใไธ่ฆง่กจ็คบใงใใพใใ
$ crontab -l
ใ/etc/cron.d/ใใใฃใฌใฏใใชใซใ/etc/crontabใใใกใคใซใจๅใๆงๆใฎใใกใคใซใๆ ผ็ดใใใฆใใพใใ
ใใ ใใใใฎใใฃใฌใฏใใชๅ
ใงใใกใคใซใฎไฝๆใจๅคๆดใใงใใใฎใฏrootใฆใผใถใผใฎใฟใจใชใใพใใ
crontab ใฎใใกใคใซๅคๆดๅพใใใผใขใณใฏๅ่ตทๅใฏไธ่ฆใงใใ
ๆธๅผ
crontabใ[ใชใใทใงใณ]
ใชใใทใงใณ | ๆฆ่ฆ |
---|---|
-e | ็ฐๅขๅคๆฐ VISUAL ใใใใฏ EDITOR ใงๆๅฎใใใฆใใใจใใฃใฟใผใไฝฟใฃใฆใ็พๅจใฎ crontab ใ็ทจ้ใใใฎใซไฝฟใใใใ็ทจ้็ตไบๅพใ ๅค ๆดใใใ crontab ใฏ่ชๅ็ใซใคใณในใใผใซใใใใ |
-uใใฆใผใถใผ | ใฉใฎใฆใผใถใcrontabใ่จญๅฎใใใฎใใๆๅฎใใพใใ็็ฅใใๅ ดๅใฏcrontabใณใใณใใๅฎ่กใใใฆใผใถใง่จญๅฎใใใพใใ |
-l | ็พๅจใฎ crontab ใฎๅ ๅฎนใๆจๆบๅบๅใธ่กจ็คบใใใใ |
-r | ็พๅจใฎ crontab ใใกใคใซใๅ้คใใใ๏ผๅ จใฆใฎ่จญๅฎใๅ้คใใใ๏ผ |
- cron ใตใผใในใฎ่ตทๅใจๅๆญข
cronใตใผใในใๅฎ่กไธญใใฉใใใฏใใ/sbin/service crond statusใใณใใณใใง็ขบ่ชใงใใพใใ
่ตทๅใใใซใฏใใ/sbin/service crond startใใณใใณใใไฝฟ็จใใพใใ
ๅๆญขใใใซใฏใใ/sbin/service crond stopใใณใใณใใไฝฟ็จใใพใใ
ใตใผใในใฏใใผใๆใซ่ตทๅใใใฎใไธ่ฌ็ใงใใ
ไฝฟ็จไพ
ไปฅไธใฎใณใใณใใงcrontabใ่ตทๅใใพใ.
$ crontab -e
tmpใใฉใซใไปฅไธใซใ/tmp/crontab.ใใใใจใใใใกใคใซใๅบ็พใใใฎใงใใใญในใใจใใฃใฟใ้ใใๅฎๆๅฎ่กใใใๆ้ใจใใฎในใฏใชใใใๆธใ่พผใฟ่จญๅฎใ่กใใพใใ
crontabใฎ่จ่ผไพ
9ๆ๏ฝ11ๆใฎ0ๅ,30ๅใซhome/pi/script_a.pyใๅฎ่กใใๅ ดๅ
00,30 9-11 * * * python3 home/pi/script_a.py
็ตๆฅ,10ๅๆฏใซhome/pi/script_a.pyใๅฎ่กใใๅ ดๅ
*/10 * * * * python3 home/pi/script_a.py
่ตทๅๆใซๆฏๅๅฎ่กใใๅ ดๅ
@reboot python3 home/pi/script_a.py
โ ็ป้ฒใใใฆใใcronใ็ขบ่ช
$ crontab -l
้ข้ฃ่จไบ



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