Improve SDSIO-Server CLI help and error messages

[ReinhardKeil]

Not sure if this is easy or not, as Python has it's own way to create help output.

Instead of

>python sdsio-server.py
usage: sdsio-server.py [-h] [--verbose] {socket,serial,usb} ...
sdsio-server.py: error: the following arguments are required: server_type

Output

>python sdsio-server.py
usage: sdsio-server.py [-h] [--verbose] {socket | serial | usb} [options]
sdsio-server.py: error: server-type specification is required: {socket | serial | usb}

Command line syntax conventions are here
https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/command-line-syntax-key

[DavidLesnjak]

Currently, all our Python scripts in SDS rely on the default behavior of argparse. To achieve the desired format for the help and error output, we would need to override the default ArgumentParser.error() method.

However, rather than applying this as a one-off solution, it would make more sense to implement this in a generic and reusable way, so it can be shared across all our Python tools.

To do this properly it would likely take a few days of work. Given the current priorities, I don’t think this is feasible to include in the 2.0.0 release.

[ReinhardKeil]

this is too complicated

[ReinhardKeil]

Maybe we can somewhat streamline the help screen. I did not realize that the tool had a workdir as the help screen is incomplete when you enter for example

sdsio-server -h usb

[DavidLesnjak]

I updated argument parsing - messages and errors.

Here are example outputs:

1.)

> python sdsio-server.py                     
Press Ctrl+C to exit.
usage: sdsio-server.py [-h] [--verbose] {socket | serial | usb} [options]
sdsio-server.py: error: server-type specification is required: {socket | serial | usb}

Get help for a server type:
  sdsio-server.py <server-type> -h
Examples:
  sdsio-server.py socket -h
  sdsio-server.py serial -h
  sdsio-server.py usb -h

2.)

> python sdsio-server.py -h
Press Ctrl+C to exit.
usage: sdsio-server.py [-h] [--verbose] {socket | serial | usb} [options]

SDS I/O server

optional arguments:
  -h, --help               show this help message and exit
  --verbose, -v            Enable debug logging

server type:
  {socket | serial | usb}
    socket                 Run TCP socket server
    serial                 Run serial server
    usb                    Run USB bulk server

Get help for a server type:
  sdsio-server.py <server-type> -h
Examples:
  sdsio-server.py socket -h
  sdsio-server.py serial -h
  sdsio-server.py usb -h

3.)

> python sdsio-server.py wrong_server_type
Press Ctrl+C to exit.
usage: sdsio-server.py [-h] [--verbose] {socket | serial | usb} [options]
sdsio-server.py: error: argument {socket | serial | usb}: invalid choice: 'wrong_server_type' (choose from 'socket', 'serial', 'usb')

4.)

> python sdsio-server.py socket -h        
Press Ctrl+C to exit.
usage: sdsio-server.py socket [--ipaddr <IP> | --interface <Interface>] [--port <TCP Port>] [--workdir <Work dir>]

optional arguments:
  -h, --help               show this help message and exit

socket arguments (optional):
  --ipaddr <IP>            Server IP address (cannot be used with --interface)
  --interface <Interface>  Network interface (cannot be used with --ipaddr)
  --port <TCP Port>        TCP port (default: 5050)
  --workdir <Work dir>     Directory for SDS files (default: current directory)

5.)

> python sdsio-server.py socket --wrong_arg
Press Ctrl+C to exit.
usage: sdsio-server.py socket [--ipaddr <IP> | --interface <Interface>] [--port <TCP Port>] [--workdir <Work dir>]
sdsio-server.py socket: error: unrecognized arguments: --wrong_arg

For help on how to use the socket server and its arguments, run: sdsio-server.py socket -h

6.)

> python sdsio-server.py socket --interface "9374361C-7ACA-45C2-9B7C-03520DD7A30F" --ipaddr 192.168.1.1
Press Ctrl+C to exit.
usage: sdsio-server.py socket [--ipaddr <IP> | --interface <Interface>] [--port <TCP Port>] [--workdir <Work dir>]
sdsio-server.py socket: error: options --ipaddr and --interface are mutually exclusive.

For help on how to use the socket server and its arguments, run: sdsio-server.py socket -h

7.)

> python sdsio-server.py serial -h
Press Ctrl+C to exit.
usage: sdsio-server.py serial -p <Serial Port> [--baudrate <Baudrate>] [--parity <Parity>] [--stopbits <Stop bits>] [--connect-timeout <Timeout>] [--workdir <Work dir>]

optional arguments:
  -h, --help                   show this help message and exit

serial arguments (required):
  -p <Serial Port>             Serial port (required)

serial arguments (optional):
  --baudrate <Baudrate>        Baudrate (default: 115200)
  --parity <Parity>            Parity: N=None, E=Even, O=Odd, M=Mark, S=Space (default: N)
  --stopbits <Stop bits>       Stop bits: 1, 1.5, 2 (default: 1)
  --connect-timeout <Timeout>  Serial port connection timeout in seconds (default: no timeout)
  --workdir <Work dir>         Directory for SDS files (default: current directory)

8.)

> python sdsio-server.py serial                                                                        
Press Ctrl+C to exit.
usage: sdsio-server.py serial -p <Serial Port> [--baudrate <Baudrate>] [--parity <Parity>] [--stopbits <Stop bits>] [--connect-timeout <Timeout>] [--workdir <Work dir>]
sdsio-server.py serial: error: the following arguments are required: -p

For help on how to use the serial server and its arguments, run: sdsio-server.py serial -h

9.)

> python sdsio-server.py usb -h   
Press Ctrl+C to exit.
usage: sdsio-server.py usb [--workdir <Work dir>] [--high-priority]

optional arguments:
  -h, --help            show this help message and exit

usb arguments (optional):
  --workdir <Work dir>  Directory for SDS files (default: current directory)
  --high-priority       Enable high-priority threading for USB Server (default: off)

@ReinhardKeil — could you take a look and share any feedback? Thank you.