Focused Git diffs for humans and LLMs: prints only meaningful changed files (skips assets/vendor dirs), groups by file with headers, and supports path filtering—perfect for pasting compact context into prompts.

README.md

git_diff_filtered — focused diffs for humans and LLMs

A small Bash function that prints only the meaningful parts of your Git diff, skipping asset/vendor directories and binary-ish files. Output is grouped by file with a clear header, making it ideal for quickly reviewing changes or pasting compact, high-signal code context into LLM prompts.

Why

• Less noise, more signal. Excludes node_modules/, .yarn, .astro, and common binary/extensions by default.
• LLM-friendly. Keeps diffs tight to save tokens and reduce hallucinations; per-file headers help models understand boundaries.
• Convenient. One call prints all filtered diffs, or you can narrow to a path.

The function

Put this in ~/.bashrc or ~/.zshrc, then source it. (Works best in Bash; in Zsh you can also put it into a #!/usr/bin/env bash script.)

git_diff_filtered.sh

git_diff_filtered() {
  cd "$(git rev-parse --show-toplevel)" || return 1

  local -a EXCLUDE_DIRS=("node_modules/" ".yarn" ".astro")
  local -a EXCLUDE_EXTS=("png" "jpg" "jpeg" "gif" "svg" "ico" "webp" "bmp" "tiff" "mp4" "mp3" "wav" "ogg" "pdf" "woff" "woff2" "ttf" "eot" "zip" "tar" "gz")
  local target_file="$1"

  # Get all changed files
  local changed_files
  changed_files=$(git diff --name-only)

  if [[ -z "$changed_files" ]]; then
    echo "No changes to diff."
    return 0
  fi

  local -a filtered_files=()
  while IFS= read -r file; do
    local skip=false

    # Skip excluded dirs
    for pattern in "${EXCLUDE_DIRS[@]}"; do
      if [[ "$file" == $pattern* ]]; then
        skip=true
        break
      fi
    done
    $skip && continue

    # Skip excluded extensions
    for ext in "${EXCLUDE_EXTS[@]}"; do
      if [[ "$file" == *".${ext}" ]]; then
        skip=true
        break
      fi
    done
    $skip && continue

    filtered_files+=("$file")
  done <<< "$changed_files"

  if [[ ${#filtered_files[@]} -eq 0 ]]; then
    echo "No changed files after filtering."
    return 0
  fi

  # Target file filtering
  if [[ -n "$target_file" ]]; then
    local canonical_arg="${target_file#./}"
    local found=0
    for file in "${filtered_files[@]}"; do
      if [[ "$file" == "$canonical_arg"* ]]; then
        echo -e "\n\033[1;36m=== $file ===\033[0m"
        git --no-pager diff --color=always -- "$file"
        echo
        found=1
      fi
    done
    (( found == 0 )) && echo "No changes to diff for '$target_file'."
    return 0
  fi

  # Print all filtered changed files
  for file in "${filtered_files[@]}"; do
    echo -e "\n\033[1;36m=== $file ===\033[0m"
    git --no-pager diff --color=always -- "$file"
    echo
  done
}