sysctl : configure kernel parameters
[SYNOPSIS] sysctl OPTION
OPTION
-a display all variables
-b print value without new line
-e ignore unknown variables errors
-N print variable names without values
-n print only values of the given variable(s)
-p FILE read values from file
--system read values from all system directories
-r PATTERN select setting that match expression
-q do not echo variable set
-w enable writing a value to variable
-h display help and exit
-V output version information and exit