Add an option to change default cli prompt

[laixintao]

See the discussion here:

http://redisdoc.com/transaction/exec.html#comment-4588712198

https://stackoverflow.com/questions/52690515/change-redis-command-prompt-text/52691005

[guoweikuang]

I don't think it's necessary, so I can know more clearly that I am currently on the redis server.

[laixintao]

@guoweikuang Yes normally you don't need this, only if you want to make the prompt shorter on purpose.

For example, your redis domain name is too long.

When you do this, like --prompt={host} (yes, wen can let user setting it with python's template), I think you already know what you are doing.

[laixintao]

The usage like this:

$ iredis --prompt='{host[:10]}'  # set hostname max length is 10

$ iredis --prompt='{host[:10]:{port}[{db}]'

$ iredis --prompt='{port}' # only show port on prompt

[laixintao]

Client source port is supported.

[laixintao]

connection id;
client name;

[laixintao]

server cluster name;
server role(master/slave)

[aymericbeaumet]

I'm embedding iredis into an in-house CLI for our engineering team, and the --prompt flag could come handy (supported by some other tools like https://github.com/dbcli/pgcli).

Would you accept a PR in that direction?

[laixintao]

@aymericbeaumet sure thing. Is #114 (comment) looks good to you?

and what placeholders do you want?
currently what I can come with are:

• host
• port
• db number
• client id?
• client port?
• current username used to auth?

any others?

[aymericbeaumet]

@aymericbeaumet sure thing. Is #114 (comment) looks good to you?

Yes, that should be doable using some kind of template engine (I'm not a Python developer).

currently what I can come with are:

Yes that looks good. Nothing else comes to mind atm. I guess it will be easy to add once we get the basic structure in place.

[aymericbeaumet]

@laixintao ready for review: #437

[laixintao]

@aymericbeaumet iredis 1.12.1 released, enjoy.
https://github.com/laixintao/iredis/releases/tag/v1.12.1

FYI, documentation updated:

Change The Default Prompt

You can change the prompt str, the default prompt is:

127.0.0.1:6379>

Which is rendered by {host}:{port}[{db}]> , you can change this via --prompt option or change
iredisrc
config file. The prompwt string uses python string format engine, supported
interpolations:

• {client_name}
• {db}
• {host}
• {path}
• {port}
• {username}
• {client_addr}
• {client_id}

The --prompt utilize
Python String format engine,
so as long as it is a valid string formatter, it will work( anything that
"<your prompt>".format(...) accepts). For example, you can limit your Redis
server host name's length to 5 by setting --prompt to
iredis --prompt '{host:.5s}'.

[aymericbeaumet]

@laixintao Great work thanks!