# Pmap with external command

**URL:** <https://discourse.julialang.org/t/pmap-with-external-command/10676>\
**Category:** Julia at Scale\
**Created:** [May 3, 2018, 9:24am UTC](https://discourse.julialang.org/t/pmap-with-external-command/10676 "2018-05-03T09:24:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Olivier\_Merchiers](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/olivier_merchiers/32/4073_2.png) [@Olivier\_Merchiers](https://discourse.julialang.org/u/Olivier_Merchiers)\
**Post date:** [May 3, 2018, 9:24am UTC](https://discourse.julialang.org/t/pmap-with-external-command/10676/1 "2018-05-03T09:24:17Z")

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Hello everyone,

I’m not sure if this is the right category, so feel free to move it.

I have the following issue. I would like to combine pmap with an external c++ code ([scuff-em](https://github.com/HomerReid/scuff-em)). In order to streamline the workflow I made some julia functions to call scuff-em for calculations and then do the data analysis in julia also.

Scuff-em uses openmp and comes as a command line tool which is usually ran in the shell. Thereto in julia I created a wrapper function which calls something like:

```julia
run(`scuff-neq --Geometry $file1 --OmegaFile $file2 `)

```

My question is : Does it make sense to use julia’s pmap to start separate jobs on a machine with 2 processors (each having 16 cores) of such an external program that makes use of openmp?

Is there a more appropriate/better strategy for doing this than using pmap?

Many thanks in advance,  
Olivier