Set Linux execute permission for file in Web-IDE
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### Proposal
Please provide some means in the Web-IDE to set the execute flag for files.
This is needed for the following examples:
1. In https://gitlab.com/juergen.kosel.jk/gcc-coverage-example/-/merge_requests/5/diffs the script `hello_world.sh` has been added by the Web-IDE. But the pipeline fails because this script has no execute flag.
2. Some of my colleges work on Windows. So they have no means to set the Linux file permissions.
The current workaround for this would be, to clone the repository to some Linux PC and then run:
```bash
chmod +x hello_world.sh
git add hello_world.sh
git commit -m"Set exec permission"
```
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