Many useless trailing blanks in source code

[guillaumelambert]

Trailing blanks are generally and strongly dis-advised by most programming languages best practices.
It is commonly admitted that they complicate the code maintenance.
Though, many can be found in the sonic-buidimage repo source code (about 17400 lines).
Also no dedicated linter to address this issue can be found in the SONiC Azure CI.

[liushilongbuaa]

grep -Eo " *$" ./ -r --exclude-dir .git | awk -F: '{print$1}' | xargs -i sudo sed -i "s/ *$//" {}
How about bash command to remove tail spaces?
I tried locally and got 17477 lines added, 17481 lines removed.
git diff --numstat | awk '{s+=$1} END {print s}'
But removing all tail spaces is a big PR. It is hard to review.
If we add it to CI pipeline. We need to push commits to original PR. There maybe permission issue.

[guillaumelambert]

grep -Eo " *$" ./ -r --exclude-dir .git | awk -F: '{print$1}' | xargs -i sudo sed -i "s/ *$//" {} How about bash command to remove tail spaces? I tried locally and got 17477 lines added, 17481 lines removed. git diff --numstat | awk '{s+=$1} END {print s}' But removing all tail spaces is a big PR. It is hard to review. If we add it to CI pipeline. We need to push commits to original PR. There maybe permission issue.

Thanks for your feedback. Such shell scripts commands do work.
Though, as stated in the commit Orange-OpenSource@1aebc16 in one of the related PRs, trailing blanks removal of some .conf files in the src folder made some tests fail during build phase. And jinja templates in docker folder use a known hack that requires trailing blanks... So we will have to deal with some exceptions at least temporarily. This means incorporating more commands and potentially complex regex in such a shell script.
I proposed in #15115 a different solution based on tox & pre-commit, which is IMHO more flexible and maintainable in a CI. It embeds a tox profile dedicated to the CI that allows to check only files modified since the introduction of this PR.

I do agree that trailing blanks complete trimming would be a big PR.
cf #15115 (comment)
I already proposed and split it in several pieces to ease its review and merge. Hope this helps. I noticed some have been already merged.

I also understand from your comment that sudo permissions are required to clean some files. But I haven't caught where.
Please can you be more precise about it. Is it all over the code or just a specific folder ? It may explain the difference of modified lines you observed. Thx in advance.