Shell scripts read configuration file parameters.

1. When reading the configuration file, all lines marked by comment # and blank lines are filtered out by sed-e'/#. * | * $/d' $ env _ file。

2. Match these lines with the specified parameters and intercept the corresponding values awk-f "$ {param} ="/$ {param} =/{print \ $2} ".

3. There may be many results. Take the last value tail -n 1.

4. These three steps are all connected by the | pipe symbol, and its function is to take the current result as the input of the next command and process it continuously to achieve the ultimate goal of obtaining parameters.