d = "diff";
      ds = "diff --staged";

      ca = "commit -a";

      a = ''
        !f() { \
                for pattern in "$@"; do \
                    matches=$(git ls-files | grep -i "$pattern"); \
                    if [ -z "$matches" ]; then \
                        echo "no files found matching \"$pattern\""; \
                        continue; \
                    fi; \
                    if [ $(echo "$matches" | wc -l) -eq 1 ]; then \
                        git add "$matches"; \
                        echo "added: $matches"; \
                    else \
                        echo "multiple matches for \"$pattern\":"; \
                        echo "$matches"; \
                        printf "add all? (y/n): "; \
                        read response; \
                        if echo "$response" | grep -q "^[Yy]"; then \
                            echo "$matches" | xargs git add; \
                            echo "added all matches"; \
                        fi; \
                    fi; \
                done; \
            }; f'';