A way to get the directory of the source file.

[amano-kenji]

Sometimes, I want to execute an executable on a path relative to the janet source file that executes it.

For now, that doesn't seem possible.

[iacore]

awawawawawa.

(pp (dyn *args*))
(pp (dyn *current-file*))

[amano-kenji]

@iacore That doesn't give me a path to the source file.

[CFiggers]

@amano-kenji You can pass what comes back from (dyn *current-file*) to (spork/path/abspath):

# scratch.janet
(import spork/path)
(print (path/abspath (dyn *current-file*)))

$ janet scratch.janet

If you're opposed to using spork, you can look at the implementation of spork/path for how to roll your own (spork/path is implemented in pure Janet).

[amano-kenji]

I read spork/path.janet

(defmacro- decl-abspath
  [pre]
  ~(defn ,(symbol pre "/abspath")
     "Coerce a path to be absolute."
     [path]
     (if (,(symbol pre "/abspath?") path)
       (,(symbol pre "/normalize") path)
       (,(symbol pre "/join") (or (dyn :path-cwd) (os/cwd)) path))))

I think it just adds the current working directory to path.

I assume that janet doesn't let you get the source directory, yet.

jpm doesn't install a lua script into /usr/bin, either. I want to execute a lua script and get its standard output from my janet code.

[sogaiu]

The following idea does not address the issue but I think one might say it can address:

I want to execute a lua script and get its standard output from my janet code.

Within one's project directory, create the lua script named script.lua, for example.

Then, in one's project.janet, place the following:

(declare-binscript
  :main "script.lua")

Executing jpm install should lead to script.lua being in the same directory as jpm itself (might need to set permissions appropriately) which should be on one's PATH.

Now script.lua should be executable via os/execute or os/spawn (assuming at least :p is used).

To increase the probability of one's script being executed, it might help to choose a name for it that is unlikely to be used by other folks.

---

Update: I looked at this comment and following its advice, discovered declare-bin:

(defn declare-bin
  "Declare a generic file to be installed as an executable."
  [&keys {:main main}]
  (install-rule main (dyn:binpath)))

That might be a better choice than declare-binscript because:

(defn declare-binscript
  ``Declare a janet file to be installed as an executable script. Creates
  a shim on windows. If hardcode is true, will insert code into the script
  such that it will run correctly even when JANET_PATH is changed. if auto-shebang
  is truthy, will also automatically insert a correct shebang line.
  ``

It seems declare-binscript is intended for Janet scripts.

[amano-kenji]

declare-bin is not documented, yet. That's why I didn't know about it. But, declare-bin can be a workaround.