macOS Sequoia and Tahoe HP Laserjet P1102 drivers

#!/usr/bin/env bash
#
# Downloads the official HP Printer Driver installer and patches its OS version gate,
# so it installs on macOS releases newer than Sequoia (15.x), e.g. Tahoe (26.x).
#
# Instructions:
# 1. save the whole contents as a new file, e.g. patch-hp-printer-driver.sh
# 2. make it executable. From a terminal, in the same folder where you saved it: chmod +x patch-hp-printer-driver.sh
# 3. run it: ./patch-hp-printer-driver.sh
# 4. The script will notify about the the patched installer (saved in the same folder). You can then run it to install the drivers.
#
set -euo pipefail

readonly DOWNLOAD_URL="https://ftp.hp.com/pub/softlib/software12/HP_Quick_Start/osx/Applications/ASU/HewlettPackardPrinterDrivers.dmg"
readonly DMG_NAME="HewlettPackardPrinterDrivers.dmg"
readonly PKG_NAME="HewlettPackardPrinterDrivers.pkg"
readonly EXPANDED_DIR="drivers"
readonly PATCHED_PKG="HewlettPackardPrinterDrivers-patched.pkg"
readonly ORIGINAL_VERSION="15.0"
readonly PATCHED_VERSION="27.0"
readonly MAX_SUPPORTED_MAJOR=15

WORK_DIR="$(pwd)"
MOUNT_POINT=""

cleanup() {
    if [[ -n "$MOUNT_POINT" && -d "$MOUNT_POINT" ]]; then
        hdiutil detach "$MOUNT_POINT" -quiet -force >/dev/null 2>&1 || true
    fi
}
trap cleanup EXIT

check_os_version() {
    local os_version major
    os_version="$(sw_vers -productVersion)"
    major="${os_version%%.*}"

    echo "Detected macOS version: $os_version"

    if (( major < MAX_SUPPORTED_MAJOR )); then
        echo "This OS version is already supported by the official installer. Patch not needed."
        return 1
    fi

    echo "This OS version (macOS $major) is newer than the installer's supported version ($ORIGINAL_VERSION). Patch needed."

    local patched_major="${PATCHED_VERSION%%.*}"
    if (( major > patched_major )); then
        echo "Warning: macOS $major is newer than the patched version ceiling ($PATCHED_VERSION). The patched installer's version check may still reject this OS."
    fi

    return 0
}

download_dmg() {
    if [[ -f "$WORK_DIR/$DMG_NAME" ]]; then
        echo "$DMG_NAME already exists, skipping download."
        return
    fi

    echo "Downloading HP Printer Driver..."
    curl -fSL -o "$WORK_DIR/$DMG_NAME" "$DOWNLOAD_URL"
}

extract_pkg_from_dmg() {
    echo "Mounting $DMG_NAME..."
    MOUNT_POINT="$(mktemp -d /tmp/hp-driver-mount.XXXXXX)"
    hdiutil attach "$WORK_DIR/$DMG_NAME" -nobrowse -quiet -mountpoint "$MOUNT_POINT"

    local src_pkg
    src_pkg="$(find "$MOUNT_POINT" -maxdepth 2 -name "$PKG_NAME" -print -quit)"
    if [[ -z "$src_pkg" ]]; then
        echo "Error: could not find $PKG_NAME inside the mounted image." >&2
        exit 1
    fi

    echo "Extracting $PKG_NAME..."
    cp "$src_pkg" "$WORK_DIR/$PKG_NAME"

    hdiutil detach "$MOUNT_POINT" -quiet
    rmdir "$MOUNT_POINT"
    MOUNT_POINT=""
}

patch_pkg() {
    echo "Expanding $PKG_NAME..."
    rm -rf "$WORK_DIR/$EXPANDED_DIR"
    pkgutil --expand "$WORK_DIR/$PKG_NAME" "$WORK_DIR/$EXPANDED_DIR"

    local distribution_file="$WORK_DIR/$EXPANDED_DIR/Distribution"
    if [[ ! -f "$distribution_file" ]]; then
        echo "Error: Distribution file not found at $distribution_file" >&2
        exit 1
    fi

    echo "Patching version check ($ORIGINAL_VERSION -> $PATCHED_VERSION)..."
    sed -i '' "s/system\.version\.ProductVersion, '$ORIGINAL_VERSION'/system.version.ProductVersion, '$PATCHED_VERSION'/" "$distribution_file"

    echo "Flattening patched package..."
    rm -f "$WORK_DIR/$PATCHED_PKG"
    pkgutil --flatten "$WORK_DIR/$EXPANDED_DIR" "$WORK_DIR/$PATCHED_PKG"
}

cleanup_intermediate_files() {
    echo "Cleaning up intermediate files..."
    rm -rf "$WORK_DIR/$EXPANDED_DIR"
}

main() {
    local needs_patch=1
    check_os_version || needs_patch=0

    if [[ $needs_patch -eq 0 ]]; then
        echo "Nothing to do."
        exit 0
    fi

    download_dmg
    extract_pkg_from_dmg
    patch_pkg
    cleanup_intermediate_files

    echo "Done. Patched installer ready at: $WORK_DIR/$PATCHED_PKG"
}

main