tree 2521e412795d0020483d589c684f37516f55fd03
parent 814645f42fae3e6dea994f88aa3b67cf43958dcf
author Abhijeet Rastogi <abhijeet.1989@gmail.com> 1668688958 -0800
committer Willy Tarreau <w@1wt.eu> 1668830689 +0100
encoding latin1

MINOR: cli: print parsed command when not found

It is useful because when we're passing data to runtime API, specially
via code, we can mistakenly send newlines leading to some lines being
wrongly interpretted as commands.

This is analogous to how it's done in a shell, example bash:

  $ not_found arg1
  bash: not_found: command not found...
  $

Real world example: Following the official docs to add a cert:

  $ echo -e "set ssl cert ./cert.pem <<\n$(cat ./cert.pem)\n" | socat stdio tcp4-connect:127.0.0.1:9999

Note, how the payload is sent via '<<\n$(cat ./cert.pem)\n'. If cert.pem
contains a newline between various PEM blocks, which is valid, the above
command would generate a flood of 'Unknown command' messages for every
line sent after the first newline. As a new user, this detail is not
clearly visible as socket API doesn't say what exactly what was 'unknown'
about it. The cli interface should be obvious around guiding user on
"what do do next".

This commit changes that by printing the parsed cmd in output like
'Unknown command: "<cmd>"' so the user gets clear "next steps", like
bash, regarding what indeed was the wrong command that HAproxy couldn't
interpret.

Previously:

  $ echo -e "show version\nhelpp"| socat ./haproxy.sock - | head -n4
  2.7-dev6

  Unknown command, but maybe one of the following ones is a better match:
    add map [@<ver>] <map> <key> <val>      : add a map entry (payload supported instead of key/val)

Now:
  $ echo -e "show version\nhelpp"| socat ./haproxy.sock - | head -n4
  2.7-dev8-737bb7-156

  Unknown command: 'helpp', but maybe one of the following ones is a better match:
    add map [@<ver>] <map> <key> <val>      : add a map entry (payload supported instead of key/val)