sehll basis:
https://www.runoob.com/linux/linux-shell-variable.html
mysql backup script:
https://www.cnblogs.com/tengfei520/p/7928700.html
shell basic questions:
https://blog.csdn.net/qq_42914528/article/details/93149000
shell example:
https://www.jb51.net/article/67112.htm
Direct running in the background script test.sh:./test.sh &
view tasks in the current shell environment has been started: jobs
will test.sh switched to the foreground: fg% number ( "number" to use the jobs command to view the [] the figures are not pid)
interrupt running in the background test.sh script: first fg% number to the foreground, and then ctrl + c; or directly kill% number
Uninterrupted run in the background test.sh:nohup ./test.sh & (test.sh print information will be output to nohup.out in the current directory)
using the jobs can be seen in the running state test.sh
use ps - ef | grep test.sh can view test.sh script running process
to exit the current shell terminal, re-open, see test.sh not using jobs are running, but using ps -ef can see