# Running commands against PR branches

**URL:** <https://discuss.circleci.com/t/running-commands-against-pr-branches/3330>\
**Category:** Build Environment\
**Tags:** git\
**Created:** [April 13, 2016, 9:07pm UTC](https://discuss.circleci.com/t/running-commands-against-pr-branches/3330 "2016-04-13T21:07:12Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![njj](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/njj/32/2463_2.png) [@njj](https://discuss.circleci.com/u/njj)\
**Post date:** [April 13, 2016, 9:07pm UTC](https://discuss.circleci.com/t/running-commands-against-pr-branches/3330/1 "2016-04-13T21:07:12Z")

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Hello all,

I’m essentially trying to run this command:

`git diff my-feature..master | xargs eslint`

The only issue I have is I need to make `master` and `my-feature` variables based on what is setup in the pull request. So essentially running eslint ONLY on the diff between a PR branch and the branch it is attempting to be merged into.

Any ideas?

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<div class="post-metadata">

**Author:** ![Caerbannog](https://sea2.discourse-cdn.com/circleci/user_avatar/discuss.circleci.com/caerbannog/32/8664_2.png) [@Caerbannog](https://discuss.circleci.com/u/Caerbannog)\
**Post date:** [November 22, 2017, 9:16am UTC](https://discuss.circleci.com/t/running-commands-against-pr-branches/3330/2 "2017-11-22T09:16:24Z")

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**[EDIT] This does not work for PRs containing multiple commits. CIRCLE\_COMPARE\_URL refers to diffs introduced by a single git push.**

You can follow this idea:

> [@Early success in a build](https://discuss.circleci.com/t/early-success-in-a-build/14461/2):
>
> The approach was to create a logical\_changes.sh which parses the git refs in CIRCLE\_COMPARE\_URL to determine the appropriate git diff ref1 ref2 --name-only command to run.

Here is a code example:

```
#CIRCLE_COMPARE_URL=https://github.com/dtprotel/protel360/compare/e8f67d33a268...1d340f4990b5
#Parsing this variable inside circle ci exports.

#Get Commit Ids Part
COMMIT_ID_PARTS=""
IFS='/'
splittedArray=$CIRCLE_COMPARE_URL
for x in $splittedArray
do
    COMMIT_ID_PARTS=$x
done
printf "> Build is between commits : $COMMIT_ID_PARTS\n"

```

(source [NameBright - Coming Soon](http://codegist.net/snippet/shell/circle_ci_deploysh_erdemolkun_shell))

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<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/circleci/original/3X/5/1/511608acda8e85906e15909b57bd0a46c1dbe291.png) [@system](https://discuss.circleci.com/u/system)\
**Post date:** [June 18, 2018, 11:32am UTC](https://discuss.circleci.com/t/running-commands-against-pr-branches/3330/3 "2018-06-18T11:32:02Z")

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