# git difftool -I and git diff -I behave differently

1 messages from 2021-03-11 to 2021-03-11. Participants: Mustafa Zengin.
Thread: https://gitlist.dev/t/55296

## Mustafa Zengin, 2021-03-11 20:18

Subject: git difftool -I and git diff -I behave differently
Message-ID: <CAJ-1jP7fy95V5ROj0gE3UC9zn5f=8pTTGy1Y7cwQtx7DidEhqw@mail.gmail.com>
URL: https://gitlist.dev/e/CAJ-1jP7fy95V5ROj0gE3UC9zn5f%3D8pTTGy1Y7cwQtx7DidEhqw%40mail.gmail.com

```
Hi,

git difftool and git diff behave differently for option -I.

Repro steps:
1. Add a line with "text" into a file (without the quotes)
2. Run
  git diff -I"text"
3. Observe that no output is returned
4. Run
  git difftool -I"text"
5. Observe that the assigned diff tool is opened with the change
including "text".

Expected:
In step 5, no diff is shown.

My expectation is based on three things:
1. -S and -G options behave the same for `git diff` and `git difftool`.
2. Quote from https://git-scm.com/docs/git-difftool
    "See git-diff[1] for the full list of supported options."
   It implies that all `git diff` options are inherited to `git difftool`.
3. It looks like the command is attempting to parse the option so it
is not completely ignored. If I make the regex malformed, e.g.
     git difftool -I"*text"
   I get back:
     error: invalid regex given to -I: '*text'

StackOverflow post:
https://stackoverflow.com/questions/66574689/git-difftool-with-i-option

Versions tested:
Windows: git version 2.30.0.windows.1
Ubuntu: git version 2.30.2

Thanks,
Mustafa

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