So, how could we turn one of our scripts into a daemon? One first attempt could be using &. The trailing ampersand is a Bash built-in which instructs the shell to run the command in the background inside a subshell. Once the command is executed, the shell does not wait for it to finish but returns a code 0, which means successful, and proceeds further in any other commands that are to be executed:
zarrelli:~$ ls -lah & ps -jf
[1] 13704
total 48K
drwxr-xr-x 4 zarrelli zarrelli 4.0K Apr 12 14:12 .
drwxr-xr-x 4 zarrelli zarrelli 4.0K Apr 12 19:37 ..
-rw-r--r-- 1 zarrelli zarrelli 11 Apr 10 09:20 controller
-rwxr--r-- 1 zarrelli zarrelli 121 Apr 11 18:30 coproc.sh
-rwxr--r-- 1 zarrelli zarrelli 961 Apr 11 12:19 environment.sh
-rwxr--r-- 1 zarrelli zarrelli 382 Apr 11 10:08 looping.sh
-rw-r--r-- 1 zarrelli zarrelli 0 Apr 10 09:20 myfile.txt
-rw-r--r-- 1 zarrelli zarrelli 122 Apr...