Read history command then return to command line. How to fix the problem?

[emisjerry]

Hi,

I wrote a test Lua script that pipes the history output to fzf. After selection, I use awk to extract the command and write it to a file. Then I read the file contents and pass them back to Nyagos. I want Nyagos to display the read content on the command line without executing it.

Pressing C_w correctly outputs without execution, but the hfzf alias executes instead. How should hfzf be modified to work correctly?

nyagos.alias.hfzf=function(args)
  local _sQuery = ""
  if args[1] then
    _sQuery = args[1]
  end
  local _sResult = ""
  local _sCmd = 'history | fzf --cycle --tac '
  if string.len(_sQuery) > 0 then
    _sCmd = _sCmd .. '--query=' .. _sQuery
  end
  _sCmd = _sCmd .. ' | awk "{match($0, /\\] (.*) \\(/, arr); print arr[1]}" '
  _sResult = nyagos.eval(_sCmd)
  print('Exec: ' .. _sResult .. '\n')
  return _sResult
end

nyagos.key.C_w = function(this)
  local _sResult = ""
  local _sFilename = "c:\\temp\\_nyagos_hfzf.txt"
  local _sCmd = 'history | fzf --cycle --tac | awk "{match($0, /\\] (.*) \\(/, arr); print arr[1]}"  '
  _sResult = nyagos.eval(_sCmd)
  --print('Exec: ' .. _sResult .. '\n')
  return _sResult
end

[hymkor]

Thank you for your question.

As I checked, there is probably no way to insert text into the Readline buffer from an alias.
The history is an exception, because a reference to it exists as a global variable (although I don’t think this is an ideal design).

Currently, the return value of an alias function is executed immediately, since it doesn’t need to interact with Readline.

From what I’ve seen, several other shells do allow sending text to the input buffer, which is a sufficient reason to consider supporting this feature in Nyagos as well.

I will think about how to specify this feature. If you have any options or ideas, please feel free to share them.
For example, there could be a command like nyagos.XXXXX("draft") in the future.

[hymkor]

Just a small clarification:
Lua scripts can access some global Readline settings — such as completion functions and key bindings.
However, as mentioned earlier, there is still no path to access the input buffer of each active Readline instance.

Sorry for the earlier incomplete explanation.
I’m still positive about supporting this feature, so no worries.

[hymkor]

I've started working on this issue in PR #465 #466.
The current implementation appears to behave as expected, but the changes touch a wide range of internal components, so it will take some time before the PR is ready to be merged.

I will continue testing and refining the implementation, and I will post updates here once the situation becomes clearer.

[hymkor]

We have extended the nyagos.setnextline(TEXT) function.
With this enhancement, you can now preset any string into the next command line even from inside an alias.
I believe the script you provided will work as expected with the following modification:

--- 458-src.lua
+++ 458.lua
@@ -11,7 +11,7 @@
   _sCmd = _sCmd .. ' | awk "{match($0, /\\] (.*) \\(/, arr); print arr[1]}" '
   _sResult = nyagos.eval(_sCmd)
   print('Exec: ' .. _sResult .. '\n')
-  return _sResult
+  nyagos.setnextline(_sResult)
 end
 
 nyagos.key.C_w = function(this)

A nyagos binary that includes nyagos.setnextline can be downloaded from the following URL:

• nyagos 1.0.2009 — AppVeyor
  https://ci.appveyor.com/project/zetamatta/nyagos/build/job/22g6hqg1bqskxree/artifacts

The next official nyagos release will likely be sometime next year, but unless any issues are found, this fix will be included in that release.

[emisjerry]

Thanks. It works!

[hymkor]

Thanks for confirming.
I will merge this fix into the new branch develop-4.4.19 for the next 4.4.19 release.
Please continue using that snapshot until 4.4.19 is officially released.

[emisjerry]

I found a problem. predict_color cannot be overrided.
I changed predict_color to green in my Lua file as follow. v4.4.18_0 has changed, but hot patch cannot work.

nyagos.option.predict_color = "\027[0;32;1m"

v4.4.18_0:

Hot patch:

[hymkor]

Thank you for the bug report.
I believe the issue was caused by a recent change in the initialization order.
Previously, readline was initialized after executing the .nyagos config file, but I reversed the order so that .nyagos runs after readline initialization.

Because of this change, the value of nyagos.option.predict_color gets applied to readline before .nyagos is executed, so the updated value in .nyagos is not reflected.

I will fix this immediately.

[hymkor]

Thank you for finding the issue so quickly.

To address the problem where the settings in .nyagos were not being applied, I separated the readline initialization into two parts: one that is unaffected by configuration variables, and another that depends on them. Only the latter is now executed after .nyagos is loaded.

You can download the fixed binary from the following URL. I would appreciate it if you could try it out.

• nyagos 1.0.2011 - AppVeyor

[emisjerry]

It works now. Thanks.

[hymkor]

I have closed this discussion. Please feel free to reopen it if you need.