# @ccall for adslib.so

**URL:** <https://discourse.julialang.org/t/ccall-for-adslib-so/120863>\
**Category:** General Usage\
**Created:** [October 3, 2024, 4:11pm UTC](https://discourse.julialang.org/t/ccall-for-adslib-so/120863 "2024-10-03T16:11:34Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![yjr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yjr/32/207725_2.png) [@yjr](https://discourse.julialang.org/u/yjr)\
**Post date:** [October 3, 2024, 4:11pm UTC](https://discourse.julialang.org/t/ccall-for-adslib-so/120863/1 "2024-10-03T16:11:35Z")

</div>

Hello,  
I sucessfully used the TcAdsDll under windows which is used to communicate with beckhoff hardware. Now I m switching stuff to linux and want to use the library here which produces adslib.so [TcAdsDll](https://github.com/stlehmann/ADS). Julia can load the library but any function I try to call reports undefined symbol. What should I do ?  
Br Yves -Julien

---

<div class="post-metadata">

**Author:** ![giordano](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/giordano/32/2166_2.png) [@giordano](https://discourse.julialang.org/u/giordano)\
**Post date:** [October 3, 2024, 5:13pm UTC](https://discourse.julialang.org/t/ccall-for-adslib-so/120863/2 "2024-10-03T17:13:06Z")

</div>

If julia errors out because the symbol you’re trying to ccall it means that either you’re using the wrong name, or that the symbol is not visible. Check with

```julia
nm -D /path/to/adslib.so | grep '<symbol name>'

```

to find the function name and its visibility status.

---

<div class="post-metadata">

**Author:** ![yjr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yjr/32/207725_2.png) [@yjr](https://discourse.julialang.org/u/yjr)\
**Post date:** [October 4, 2024, 7:05am UTC](https://discourse.julialang.org/t/ccall-for-adslib-so/120863/3 "2024-10-04T07:05:45Z")

</div>

Thanks, that’s effectively the problem; this lib version does export only a part of the functions !