How exactly do you have to interpret the output of a commands "usage" output, in bash for example.
For example, on my OS X,
cp gives me
usage: cp [-R [-H | -L | -P]] [-fi | -n] [-apvX] source_file target_file cp [-R [-H | -L | -P]] [-fi | -n] [-apvX] source_file ... target_directory
- What does the nested options, like -H within -R, indicate?
- Does upper and lower case have any meaning?
- When is an argument optional, required?
I need to implement a telnet command line against a program of mine and I would like to get this straight.