Anaconda (Python) + Cmder (Clink) on Windows - Unify Dueling Custom Prompts

If you run Anaconda on windows, you have an [`activate.bat`][1] file which concludes with this line to put your current conda env on the prompt:

set PROMPT=[%CONDA_DEFAULT_ENV%] $P$G

If you run cmder on windows, there is a [nice lua script][2] to customize your prompt:

function lambda_prompt_filter()
clink.prompt.value = string.gsub(clink.prompt.value, "{lamb}", "λ")
end

clink.prompt.register_filter(lambda_prompt_filter, 40)

These two scripts do not play very nicely with each other. [Clink has an API][3] that seems like I could use to incorporate the change from `activate.bat`, but I cannot figure out how to call it from a batch file.

My overall goal is to merge these two prompts into the nicer Cmder-style. My thought is to create an environment variable, change `activate.bat` to check for the existence of the variable, and, if so, call the Clink API to change the prompt instead of `set PROMPT`. At that point I would think I could create a new filter to cleanly merge the value in. I can't figure out how to call the API from the batch file, though.

Other solutions welcome.

EDIT: Partial, non-working solution

require "os" -- added to top of file, rest in filter function
local sub = os.getenv("CONDA_DEFAULT_ENV")
if sub == nil then
sub = ""
end
print(sub)
clink.prompt.value = string.gsub(clink.prompt.value, "{conda}", sub)

I added a {conda} in the prompt definition at the very beginning; removed the prompt statement from `activate.bat`, and added this to `git_prompt_filter`. Prior to using activate, everything is fine - the `{conda}` gets suppressed by the `''`. However, if I use activate and switch into a folder with a git repo to trigger the change, I see:

`{conda}C:\...`

Does `os.getenv` not get user set variables? Don't know what else the problem would be. I also tried adding a print, it doesn't print out the contents of `CONDA...` either.

[1]:

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Why not just delete the line from `activate.bat` and do all the logic in your cmder profile? CONDA_DEFAULT_ENV will be empty if no environment is active.

This is what I do to reset the prompt and add the conda env name to the prompt:

---
-- Find out the basename of a file/directory (last element after \ or /
-- @return {basename}
---
function basename(inputstr)
sep = "\\/"
local last = nil
local t={} ; i=1
for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
--t[i] = str
--i = i + 1
last = str
end
return last
end

---
-- Find out current conda env
-- @return {false|conda env name}
---
function get_conda_env()
env_path = clink.get_env('CONDA_DEFAULT_ENV')
if env_path then
basen = basename(env_path)
return basen
end
return false
end

---
-- after conda activate: reset prompt and add conda env name
---
function conda_prompt_filter()
-- reset to original, e.g. after conda activate destroyed it...
if string.match(clink.prompt.value, "{lamb}") == nil then
-- orig: $E[1;32;40m$P$S{git}{hg}$S$_$E[1;30;40m{lamb}$S$E[0m
-- color codes: "\x1b[1;37;40m"
cwd = clink.get_cwd()
prompt = "\x1b[1;32;40m{cwd} {git}{hg} \n\x1b[1;30;40m{lamb} \x1b[0m"
new_value = string.gsub(prompt, "{cwd}", cwd)
clink.prompt.value = new_value
end
-- add in conda env name
local conda_env = get_conda_env()
if conda_env then
clink.prompt.value = string.gsub(clink.prompt.value, "{lamb}", "["..conda_env.."] {lamb}")
end
end

clink.prompt.register_filter(conda_prompt_filter, 10)

I want to build on @Jan-Schulz answer since it didn't exactly work for me in April 2017.

1. Instead of editing `cmder/vendor/clink/clink.lua` I added custom code into `cmder/config/prompt.lua` which is not overwritten on upgrade (You can add additional modifications to cmder prompt in this file as well using the clink lua api)

2. I was having an issue where the `{lamb}` was not being replaced with the proper `λ` character so I added another filter to run at the end of all processing.

<!-- language: lua -->


---
-- Find out the basename of a file/directory (last element after \ or /
-- @return {basename}
---
function basename(inputstr)
sep = "\\/"
local last = nil
local t={} ; i=1
for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
--t[i] = str
--i = i + 1
last = str
end
return last
end

---
-- Find out current conda env
-- @return {false|conda env name}
---
function get_conda_env()
env_path = clink.get_env('CONDA_DEFAULT_ENV')
if env_path then
basen = basename(env_path)
return basen
end
return false
end

---
-- after conda activate: reset prompt and add conda env name
---
function conda_prompt_filter()
-- reset to original, e.g. after conda activate destroyed it...
if string.match(clink.prompt.value, "{lamb}") == nil then
-- orig: $E[1;32;40m$P$S{git}{hg}$S$_$E[1;30;40m{lamb}$S$E[0m
-- color codes: "\x1b[1;37;40m"
cwd = clink.get_cwd()
prompt = "\x1b[1;32;40m{cwd} {git}{hg} \n\x1b[1;30;40m{lamb} \x1b[0m"
new_value = string.gsub(prompt, "{cwd}", cwd)
clink.prompt.value = new_value
end
-- add in conda env name
local conda_env = get_conda_env()
if conda_env then
clink.prompt.value = string.gsub(clink.prompt.value, "{lamb}", "["..conda_env.."] {lamb}")
end
end


function fix_lamb()
if string.match(clink.prompt.value, "{lamb}") ~= nil then
clink.prompt.value = string.gsub(clink.prompt.value, "{lamb}", "λ")
end
end

clink.prompt.register_filter(conda_prompt_filter, 1)
clink.prompt.register_filter(fix_lamb, 999)