출처:
https://blog.naver.com/dulfla_5/222899081692
https://blog.naver.com/zacra/222496979835
https://blog.naver.com/kut_da_92/222678260803
https://blog.naver.com/ollala5276/222609508726
(영문 해석)
Source:
https://www.guru99.com/crontab-in-linux-with-examples.htmlS
https://www.techtarget.com/searchdatacenter/definition/crontab
https://www.geeksforgeeks.org/crontab-in-linux-with-examples/