# Running GroIMP headless without opening and closing GroIMP every model run

**URL:** <https://fspm.discourse.group/t/running-groimp-headless-without-opening-and-closing-groimp-every-model-run/336>\
**Category:** GroIMP\
**Created:** [December 10, 2024, 11:53am UTC](https://fspm.discourse.group/t/running-groimp-headless-without-opening-and-closing-groimp-every-model-run/336 "2024-12-10T11:53:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Marloes\_Rodewijk](https://dub1.discourse-cdn.com/flex005/user_avatar/fspm.discourse.group/marloes_rodewijk/32/115_2.png) [@Marloes\_Rodewijk](https://fspm.discourse.group/u/Marloes_Rodewijk)\
**Post date:** [December 10, 2024, 11:53am UTC](https://fspm.discourse.group/t/running-groimp-headless-without-opening-and-closing-groimp-every-model-run/336/1 "2024-12-10T11:53:56Z")

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For a sensitivity and optimisation analysis of a GroIMP model through R, I call the model headless through a Windows shell command:

C: && cd “C:\Progra~1\Java\jdk-22\bin” && java -Xverify:none -Xmx14000m -jar “C:\Progra~1\GroIMP 2.1.3\core.jar” --headless “_inputfile_” “_outputfile_” --debug=INFO “_model gs file_” 2\> “_logfile_”

Such a headless run is repeated for multiple input files in a row. However, this command opens and closes GroIMP for every model run. How can I modify the headless command such that GroIMP is only openend before the first model run and closed after the last?

Thank you!

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**Author:** ![tim](https://avatars.discourse-cdn.com/v4/letter/t/ce73a5/32.png) [@tim](https://fspm.discourse.group/u/tim)\
**Post date:** [December 11, 2024, 8:36am UTC](https://fspm.discourse.group/t/running-groimp-headless-without-opening-and-closing-groimp-every-model-run/336/2 "2024-12-11T08:36:21Z")

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Hi,  
I think it would be very hard to change the headless mode to do so, but GroIMP comes with other interfaces that can be used for this purpose. You can have a look here: [tutorials:interfaces [GroIMP wiki]](https://wiki.grogra.de/doku.php?id=tutorials:interfaces)

From what you said about your project I would suggest you to either use the HTTP-server (that would work almost identical to the headless mode) or the API. There is even a small tutorial on Sensitivity anlysis in R using the API. [tutorials:sensitivity-analysis-using-grolink-and-gror [GroIMP wiki]](https://wiki.grogra.de/doku.php?id=tutorials:sensitivity-analysis-using-grolink-and-gror)