[luatex] LUA_INIT mechanism in texlua?

[Taco Hoekwater]

> On 2 Jun 2022, at 09:51, jfbu <jfbu at free.fr> wrote:
> 
> [sending from correct address jfbu at free.fr, please use it if replying]
> Hi, 
> 
> Afer reading https://www.lua.org/manual/5.1/lua.html I learned about LUA_INIT.
> 
> I have tested it and it works with my lua binary but not with texlua.

LUA_INIT is a standalone lua interpreter feature that is not present in texlua (which is itself a symlink to luatex, btw).

Neither are the other ‘lua’ executable command line options, except for the use of the global ‘arg’ variable. 

To get a similar effect, you could use:

#!/usr/bin/env texlua

assert(loadstring(os.getenv("LUA_INIT") or ''))()
foo = foo or "bonjour"
print(foo)


Best wishes,
Taco

> For my test with lua I used this file with  the executable bit on:
> 
> ---
> #!/usr/bin/env lua
> 
> foo = foo or "bonjour"
> 
> print(foo)
> ---
> 
> Then (in a bash shell):
> 
> export LUA_INIT="foo=\"Guten Tag\""
> ./test.lua
> Guten Tag
> 
> Now, a copy of the file above but using "/usr/bin/env texlua" in place of "lua" does not act the same:
> 
> ./test.texlua
> bonjour
> echo $LUA_INIT
> foo="Guten Tag"
> 
> I checked the manpage of texlua (which is the one of luatex) and see no mention.
> 
> I searched the lua.pdf documentation for string _INIT and found nothing.
> 
> Is there some replacement for LUA_INIT functionality?
> 
> Rationale of my question: I was looking into LaTeX3 documentation and wanted
> to typeset some of it including implementation. After some quick digging
> I understood that the l3build script has a variable
> typesetcmds and I first tried to set it on command line but I learned that
> it is probably not possible, then I read about LUA_INIT in the Lua documentation
> as mentioned above,
> which would be nice if it worked with l3build too (i.e. with texlua).
> 
> I would be happy to be allowed to do (bash shell) something such as
> 
> env TEXLUA_INIT='typesetcmds=""' l3build doc
> 
> rather than having to modify a file (either a l3build config or a dtx file)
> which sorts of pushes me into rebasing a branch on each pull from upstream.
> 
> Please CC jfbu if replying
> Best,
> Jean-François

— 
Taco Hoekwater              E: taco at bittext.nl
genderfluid (all pronouns)