Does Linux fail to run the script when it is switched on or off?

Does Linux fail to run the script when it is switched on or off? -- Linux general technology-Linux programming and kernel information. The following is a detailed description. Purpose: I want Red Hat to run the script testapp at startup and shutdown and print the corresponding information to a log file.
Environment:
1. testapp Creator: root
2. testapp path:/etc/init. d/testapp
3. Hard connection of testapp: ln/etc/init. d/testapp/etc/rc3.d/S91test
Ln/etc/init. d/testapp/etc/rc0.d/K91est
Chmod 744/etc/rc3.d/S91test
Chmod 744/etc/rc0.d/K91test
4. The content of testapp is as follows:
Case $1 in
'Start ')
Echo 'date' + % F % t' "system start">/var/log/test. log
;;
'Stop ')
Echo 'date' + % F % t' "system stop">/var/log/test. log
;;
Esac

Exit 0

Bytes ---------------------------------------------------------------------------------------------------
Under the root user, when testapp start or testapp stop is used, the corresponding information can be printed to the log file, but the testapp script is not run when the RedHat is switched on and off, and I do not know where the error is, please give me some advice. Thank you!