# One-liner Bash function to compare the content of two variables like git diff

The issue you're encountering is that `git diff --no-index` has limitations with process substitution on certain systems (particularly Windows/Git Bash). Here's a clean solution using regular `diff` with colors:

```bash

gdiffvars() { diff --color -u <(printf "%s\n" "$1") <(printf "%s\n" "$2"); }

```

**Usage Example:**

```bash

BEFORE="$(git config --global --list)"

# ...run your git commands here...

AFTER="$(git config --global --list)"

gdiffvars "$BEFORE" "$AFTER"

```

**Explanation:**

- `gdiffvars` uses `diff --color -u` to show differences between two variables in a unified, color-highlighted format similar to Git.

- The variables' contents are safely passed using process substitution with `printf`, ensuring multi-line data is compared correctly.

- This works in bash and other shells supporting process substitution.

**Why `git diff --no-index` fails with process substitution:**

As mentioned in the existing answer, this is a known limitation on Windows/Git Bash where process substitution creates file descriptors that `git diff` cannot properly access. The error "Could not access '/proc/2219/fd/63'" occurs because Git's implementation doesn't handle these virtual file descriptors the same way regular `diff` does.

**Notes:**

- `git diff` expects files or repository paths. To compare arbitrary data in variables, use `diff` as shown above.

- The `--color` flag provides the familiar Git-like colored output you're looking for.

- The function will work on most Unix-like systems, including Linux and macOS. For native Windows, use WSL or Git Bash for best results.

- Using `printf "%s\n"` instead of `echo` ensures proper handling of variables containing backslashes or other special characters.

This approach gives you the visual familiarity of `git diff` while being more reliable across different systems and shell environments.