# Accessing json file from CoolProp.jl c interface

**URL:** <https://discourse.julialang.org/t/accessing-json-file-from-coolprop-jl-c-interface/96292>\
**Category:** General Usage\
**Tags:** ffi, c\
**Created:** [March 19, 2023, 3:16am UTC](https://discourse.julialang.org/t/accessing-json-file-from-coolprop-jl-c-interface/96292 "2023-03-19T03:16:19Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![longemen3000](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/longemen3000/32/7298_2.png) [@longemen3000](https://discourse.julialang.org/u/longemen3000)\
**Post date:** [March 19, 2023, 3:16am UTC](https://discourse.julialang.org/t/accessing-json-file-from-coolprop-jl-c-interface/96292/1 "2023-03-19T03:16:19Z")

</div>

hi. i’m trying to make a port of some CoolProp functions in julia. The idea is to use the same CoolProp JSON files that have component properties, but read those in the julia side.  
One problem i see is that the current [CoolProp.jl](https://github.com/CoolProp/CoolProp.jl) package does not have support for the necessary function `get_fluid_param_string`. i know that those files are inside `CoolProp_jll`, but i don’t know how to query those, nor on how to use the C interface correctly.  
One option is to use the python version, and access the files from there, but that would add, of course, an extra python dependency for not much gain.  
Also, the CoolProp project is originally C++, but we are using the C interface instead, is there a way to access that C++ interface from julia instead?

---

<div class="post-metadata">

**Author:** ![longemen3000](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/longemen3000/32/7298_2.png) [@longemen3000](https://discourse.julialang.org/u/longemen3000)\
**Post date:** [March 19, 2023, 5:41am UTC](https://discourse.julialang.org/t/accessing-json-file-from-coolprop-jl-c-interface/96292/2 "2023-03-19T05:41:19Z")

</div>

the function exists in the wrapper, but it is buggy. i will submit a PR to fix that.