src/tools/linkchecker/linkcheck.sh

#!/bin/sh
#
# This is a script that can be used in each book's CI to validate links using
# the same tool as rust-lang/rust.
#
# This requires the rust-docs rustup component to be installed in the nightly
# toolchain.
#
# Usage:
#   ./linkcheck.sh <name-of-book>
#
# Options:
#
# -i        "Iterative" mode. The script will not clean up after it is done so
#           you can inspect the result, and re-run more quickly.
#
# --all     Check all books. This can help make sure you don't break links
#           from other books into your book.
#
# --path <book-path>
#           Path to the root directory for the book. Default to the current
#           working directory if omitted.

set -e

# Fetches the contents of a file from GitHub using the REST API.
# Usage: fetch_github_file OWNER REPO PATH OUTPUT_PATH
fetch_github_file() {
    owner="$1"
    repo="$2"
    path="$3"
    output="$4"

    # Hack to repurpose the function's positional parameters to conditionally
    # pass curl headers. The GITHUB_TOKEN should be set to help avoid rate
    # limits.
    if [ -n "${GITHUB_TOKEN:-}" ]
    then
        set -- -H "Authorization: Bearer $GITHUB_TOKEN"
    else
        set --
    fi

    curl -L -o "$output" \
        -H "Accept: application/vnd.github.raw" \
        "$@" \
        -H "X-GitHub-Api-Version: 2026-03-10" \
        "https://api.github.com/repos/$owner/$repo/contents/$path"
}

html_dir="$(rustc +nightly --print sysroot)/share/doc/rust/html"

if [ ! -d "$html_dir" ]
then
    echo "HTML docs are missing from sysroot: $html_dir"
    echo "Make sure the nightly rust-docs rustup component is installed."
    exit 1
fi

# Avoid failure caused by newer mdbook.
export MDBOOK_OUTPUT__HTML__INPUT_404=""

book_name=""
# Default to the current directory
book_path="."
# Iterative will avoid cleaning up, so you can quickly run it repeatedly.
iterative=0
# If "1", test all books, else only this book.
all_books=0

while [ "$1" != "" ]
do
    case "$1" in
        -i)
            iterative=1
            ;;
        --all)
            all_books=1
            ;;
        --path)
            book_path="${2:-.}"
            shift
            ;;
        *)
            if [ -n "$book_name" ]
            then
                echo "only one argument allowed"
                exit 1
            fi
            book_name="$1"
            ;;
    esac
    shift
done

if [ -z "$book_name" ]
then
    echo "usage: $0 <name-of-book>"
    exit 1
fi

if [ ! -f "$book_path/book.toml" ] && [ ! -f "$book_path/src/SUMMARY.md" ]
then
    echo "Run command in root directory of the book or provide a path to the book"
    exit 1
fi

if [ ! -d "$html_dir/$book_name" ]
then
    echo "book name \"$book_name\" not found in sysroot \"$html_dir\""
    exit 1
fi

if [ "$iterative" = "0" ]
then
    echo "Cleaning old directories..."
    rm -rf linkcheck linkchecker
fi

if [ ! -e "linkchecker/main.rs" ] || [ "$iterative" = "0" ]
then
    echo "Downloading linkchecker source..."
    mkdir linkchecker
    fetch_github_file rust-lang rust Cargo.lock linkchecker/Cargo.lock
    fetch_github_file rust-lang rust src/tools/linkchecker/Cargo.toml linkchecker/Cargo.toml
    fetch_github_file rust-lang rust src/tools/linkchecker/main.rs linkchecker/main.rs
fi

echo "Building book \"$book_name\"..."
mdbook build "$book_path"

cp -R "$html_dir" linkcheck
rm -rf "linkcheck/$book_name"
cp -R "$book_path/book" "linkcheck/$book_name"

if [ "$all_books" = "1" ]
then
    check_path="linkcheck"
else
    check_path="linkcheck/$book_name"
fi
echo "Running linkchecker on \"$check_path\"..."
cargo run --release --manifest-path=linkchecker/Cargo.toml -- "$check_path"

if [ "$iterative" = "0" ]
then
    rm -rf linkcheck linkchecker
fi

echo "Link check completed successfully!"