scripts/build_ngx_pagespeed.sh - incubator-pagespeed-ngx - Git at Google

 #!/bin/bash

 function usage() {
   echo "
 Usage: build_ngx_pagespeed.sh [options]

   Installs ngx_pagespeed and its dependencies.  Can optionally build and install
   nginx as well.

 Options:
   -v, --ngx-pagespeed-version <ngx_pagespeed version>
       What version of ngx_pagespeed to build.  Valid options include:
       * latest-beta
       * latest-stable
       * a version number, such as 1.11.33.4

       If you don't specify a version, defaults to latest-stable.

   -n, --nginx-version <nginx version>
       What version of nginx to build.  If not set, this script only prepares the
       ngx_pagespeed module, and expects you to handle including it when you
       build nginx.

       If you pass in 'latest' then this script scrapes the nginx download page
       and attempts to determine the latest version automatically.

   -m, --dynamic-module
       Build ngx_pagespeed as a dynamic module.

   -b, --builddir <directory>
       Where to build.  Defaults to \$HOME.

   -p, --no-deps-check
       By default, this script checks for the packages it depends on and tries to
       install them.  If you have installed dependencies from source or are on a
       non-deb non-rpm system, this won't work.  In that case, install the
       dependencies yourself and pass --no-deps-check.

   -d, --dryrun
       Don't make any changes to the system, just print what changes you
       would have made.

   -h, --help
       Print this message and exit."
 }

 # Prints an error message and exits with an error code.
 function fail() {
   local error_message="$@"
   echo "$@" >&2

   # Normally I'd use $0 in "usage" here, but since most people will be running
   # this via curl, that wouldn't actually give something useful.
   echo >&2
   echo "For usage information, run this script with --help" >&2
   exit 1
 }

 # Intended to be called as:
 #   bash <(curl dl.google.com/.../build_ngx_pagespeed.sh) <args>

 # If we set -e or -u then users of this script will see it silently exit on
 # failure.  Instead we need to check the exit status of each command manually.
 # The run function handles exit-status checking for system-changing commands.
 # Additionally, this allows us to easily have a dryrun mode where we don't
 # actually make any changes.
 function run() {
   if "$DRYRUN"; then
     echo "would run $@"
   else
     if ! "$@"; then
       echo "Failure running $@, exiting."
       exit 1
     fi
   fi
 }

 function redhat_is_installed() {
   local package_name="$1"
   rpm -qa $package_name | grep -q .
 }

 function debian_is_installed() {
   local package_name="$1"
   dpkg -l $package_name | grep ^ii | grep -q .
 }

 function version_sort() {
   # We'd rather use sort -V, but that's not available on Centos 5.  This works
   # for versions in the form A.B.C.D or shorter, which is enough for our use.
   sort -t '.' -k 1,1 -k 2,2 -k 3,3 -k 4,4 -g
 }

 # Compare two numeric versions in the form "A.B.C".  Works with version numbers
 # having up to four components, since that's enough to handle both nginx (3) and
 # ngx_pagespeed (4).
 function version_older_than() {
   local test_version="$1"
   local compare_to="$2"

   local older_version=$(echo $@ | tr ' ' '\n' | version_sort | head -n 1)
   test "$older_version" != "$compare_to"
 }

 function determine_latest_nginx_version() {
   # Scrape nginx's download page to try to find the most recent nginx version.

   nginx_download_url="https://nginx.org/en/download.html"
   function report_error() {
     fail "
 Couldn't automatically determine the latest nginx version: failed to $@
 $nginx_download_url"
   }

   nginx_download_page=$(curl -sS --fail "$nginx_download_url") || \
     report_error "download"

   download_refs=$(echo "$nginx_download_page" | \
     grep -o '/download/nginx-[0-9.]*[.]tar[.]gz') || \
     report_error "parse"

   versions_available=$(echo "$download_refs" | \
     sed -e 's~^/download/nginx-~~' -e 's~\.tar\.gz$~~') || \
     report_error "extract versions from"

   latest_version=$(echo "$versions_available" | version_sort | tail -n 1) || \
     report_error "determine latest version from"

   if version_older_than "$latest_version" "1.11.4"; then
     fail "
 Expected the latest version of nginx to be at least 1.11.4 but found
 $latest_version on $nginx_download_url"
   fi

   echo "$latest_version"
 }

 # Usage:
 #  install_dependencies install_pkg_cmd is_pkg_installed_cmd dep1 dep2 ...
 #
 # install_pkg_cmd is a command to install a dependency
 # is_pkg_installed_cmd is a command that returns true if the dependency is
 #   already installed
 # each dependency is a package name
 function install_dependencies() {
   local install_pkg_cmd="$1"
   local is_pkg_installed_cmd="$2"
   shift 2

   local missing_dependencies=""

   for package_name in "$@"; do
     if ! $is_pkg_installed_cmd $package_name; then
       missing_dependencies+="$package_name "
     fi
   done
   if [ -n "$missing_dependencies" ]; then
     echo "Detected that we're missing the following depencencies:"
     echo "  $missing_dependencies"
     echo "Installing them:"
     run sudo $install_pkg_cmd $missing_dependencies
   fi
 }

 function gcc_too_old() {
   # We need gcc >= 4.8
   local gcc_major_version=$(gcc -dumpversion | awk -F. '{print $1}')
   if [ "$gcc_major_version" -lt 4 ]; then
     return 0  # too old
   elif [ "$gcc_major_version" -gt 4 ]; then
     return 1  # plenty new
   fi
   # It's gcc 4.x, check if x >= 8:
   local gcc_minor_version=$(gcc -dumpversion | awk -F. '{print $2}')
   test "$gcc_minor_version" -lt 8
 }

 function continue_or_exit() {
   local prompt="$1"
   read -p "$prompt [Y/n] " yn
   if [[ "$yn" == N* || "$yn" == n* ]]; then
     echo "Cancelled."
     exit 0
   fi
 }

 # If a string is very simple we don't need to quote it.  But we should quote
 # everything else to be safe.
 function needs_quoting() {
   echo "$@" | grep -q '[^a-zA-Z0-9./_=-]'
 }

 function escape_for_quotes() {
   echo "$@" | sed -e 's~\\~\\\\~g' -e "s~'~\\\\'~g"
 }

 function quote_arguments() {
   local argument_str=""
   for argument in "$@"; do
     if [ -n "$argument_str" ]; then
       argument_str+=" "
     fi
     if needs_quoting "$argument"; then
       argument="'$(escape_for_quotes "$argument")'"
     fi
     argument_str+="$argument"
   done
   echo "$argument_str"
 }

 function build_ngx_pagespeed() {
   getopt --test
   if [ "$?" != 4 ]; then
     # Even Centos 5 and Ubuntu 10 LTS have new-style getopt, so I don't expect
     # this to be hit in practice on systems that are actually able to run
     # PageSpeed.
     fail "Your version of getopt is too old.  Exiting with no changes made."
   fi

   opts=$(getopt -o v:n:mb:pdh \
     --longoptions ngx-pagespeed-version:,nginx-version:,dynamic-module \
     --longoptions buildir:,no-deps-check,dryrun,help \
     -n "$(basename "$0")" -- "$@")
   if [ $? != 0 ]; then
     usage
     exit 1
   fi
   eval set -- "$opts"

   NPS_VERSION="latest-stable"
   NGINX_VERSION=""
   BUILDDIR="$HOME"
   DO_DEPS_CHECK=true
   DRYRUN=false
   DYNAMIC_MODULE=false
   while true; do
     case "$1" in
       -v | --ngx-pagespeed-version) shift
         NPS_VERSION="$1"
         shift
         ;;
       -n | --nginx-version) shift
         NGINX_VERSION="$1"
         shift
         ;;
       -m | --dynamic-module) shift
         DYNAMIC_MODULE=true
         ;;
       -b | --builddir) shift
         BUILDDIR="$1"
         shift
         ;;
       -p | --no-deps-check) shift
         DO_DEPS_CHECK=false
         ;;
       -d | --dryrun) shift
         DRYRUN="true"
         ;;
       -h | --help) shift
         usage
         exit 0
         ;;
       --) shift
         break
         ;;
       *)
         echo "Invalid argument: $1"
         usage
         exit 1
         ;;
     esac
   done

   if [ ! -d "$BUILDDIR" ]; then
     fail "Told to build in $BUILDDIR, but that directory doesn't exist."
   fi

   if [ "$NGINX_VERSION" = "latest" ]; then
     # When this function fails it prints the debugging information needed first
     # to stderr.
     NGINX_VERSION=$(determine_latest_nginx_version) || exit 1
   fi

   if "$DYNAMIC_MODULE"; then
     # Check that ngx_pagespeed and nginx are recent enough to support dynamic
     # modules.
     if version_older_than "$NPS_VERSION" "1.10.33.5"; then
       fail "
 You're trying to build ngx_pagespeed $NPS_VERSION as a dynamic module, but
 ngx_pagespeed didn't add support for dynamic modules until 1.10.33.5."
     fi

     if [ ! -z "NGINX_VERSION" ]; then
       if version_older_than "$NGINX_VERSION" "1.9.13"; then
         fail "
 You're trying to build nginx $NGINX_VERSION as a dynamic module but nginx didn't
 add support for dynamic modules in a way compatible with ngx_pagespeed until
 1.9.13."
       fi
     fi
   fi

   if "$DRYRUN"; then
     TEMPDIR="/tmp/output-of-mktemp"
   else
     TEMPDIR=$(mktemp -d)
     function cleanup_tempdir {
       rm -rf "$TEMPDIR"
     }
     trap cleanup_tempdir EXIT
   fi

   extra_flags=()
   # Now make sure our dependencies are installed.
   if "$DO_DEPS_CHECK"; then
     if [ -f /etc/debian_version ]; then
       echo "Detected debian-based distro."

       install_dependencies "apt-get install" debian_is_installed \
         "build-essential zlib1g-dev libpcre3 libpcre3-dev unzip"

       if gcc_too_old; then
         if [ ! -e /usr/lib/gcc-mozilla/bin/gcc ]; then
           echo "Detected that gcc is older than 4.8.  Installing gcc-mozilla"
           echo "which installs gcc-4.8 into /usr/lib/gcc-mozilla/ and doesn't"
           echo "affect your global gcc installation."
           run sudo apt-get install gcc-mozilla
         fi

         extra_flags=("--with-cc=/usr/lib/gcc-mozilla/bin/gcc" \
                      "--with-ld-opt=-static-libstdc++")
       fi

     elif [ -f /etc/redhat-release ]; then
       echo "Detected redhat-based distro."

       install_dependencies "yum install" redhat_is_installed \
         "gcc-c++ pcre-devel zlib-devel make unzip wget"
       if gcc_too_old; then
         if [ ! -e /opt/rh/devtoolset-2/root/usr/bin/gcc ]; then
           redhat_major_version=$(
             cat /etc/redhat-release | grep -o -E '[0-9]+' | head -n 1)
           if [ "$redhat_major_version" == 5 ]; then
             slc_version=5
           elif [ "$redhat_major_version" == 6 ]; then
             slc_version=6
           else
             fail "
 Unexpected major version $redhat_major_version in /etc/redhat-release:
 $(cat /etc/redhat-release) Expected 5 or 6."
           fi

           echo "Detected that gcc is older than 4.8.  Scientific Linux provides"
           echo "a gcc package that installs gcc-4.8 into /opt/ and doesn't"
           echo "affect your global gcc installation."
           slc_key="https://linux.web.cern.ch/linux/scientific6/docs/repository/"
           slc_key+="cern/slc6X/i386/RPM-GPG-KEY-cern"
           slc_key_out="$TEMPDIR/RPM-GPG-KEY-cern"
           run sudo wget "$slc_key" -O "$slc_key_out"
           run sudo rpm --import "$slc_key_out"

           repo_fname="/etc/yum.repos.d/slc${slc_version}-devtoolset.repo"
           if [ -e "$repo_fname" ]; then
             fail "Expected $repo_fname not to exist; aborting."
           fi

           repo_url="https://linux.web.cern.ch/linux/scientific${slc_version}/"
           repo_url+="/docs/repository/cern/devtoolset/"
           repo_url+="slc${slc_version}-devtoolset.repo"
           run sudo wget -O "$repo_fname" "$repo_url"
           run sudo yum install devtoolset-2-gcc-c++ devtoolset-2-binutils
         fi
         extra_flags=("--with-cc=/opt/rh/devtoolset-2/root/usr/bin/gcc")
       fi
     else
       fail "
 This doesn't appear to be a deb-based distro or an rpm-based one.  Not going to
 be able to install dependencies.  Please install dependencies manually and rerun
 with --no-deps-check."
     fi
     echo "Dependencies are all set."
   else
     echo "Not checking whether dependencies are installed."
   fi

   function delete_if_already_exists() {
     if "$DRYRUN"; then return; fi

     local directory="$1"
     if [ -d "$directory" ]; then
       if [ ${#directory} -lt 8 ]; then
         fail "
 Not deleting $directory; name is suspiciously short.  Something is wrong."
         exit 1
       fi

       continue_or_exit "OK to delete $directory?"
       run rm -rf "$directory"
     fi
   }

   nps_baseurl="https://github.com/pagespeed/ngx_pagespeed/archive"
   # In general, the zip github builds for tag foo unzips to ngx_pagespeed-foo,
   # but it looks like they special case vVERSION tags to ngx_pagespeed-VERSION.
   if [[ "$NPS_VERSION" =~ ^[0-9]*[.][0-9]*[.][0-9]*[.][0-9]*$ ]]; then
     # We've been given a numeric version number.  This has an associated tag in
     # the form vVERSION-beta.
     nps_url_fname="v${NPS_VERSION}-beta"
     nps_downloaded_fname="ngx_pagespeed-${NPS_VERSION}-beta"
   else
     # We've been given a tag name, like latest-beta.  Download that directly.
     nps_url_fname="$NPS_VERSION"
     nps_downloaded_fname="ngx_pagespeed-${NPS_VERSION}"
   fi

   nps_downloaded="$TEMPDIR/$nps_downloaded_fname.zip"
   run wget "$nps_baseurl/$nps_url_fname.zip" -O "$nps_downloaded"
   nps_module_dir="$BUILDDIR/$nps_downloaded_fname"
   delete_if_already_exists "$nps_module_dir"
   echo "Extracting ngx_pagespeed..."
   run unzip -q "$nps_downloaded" -d "$BUILDDIR"
   run cd "$nps_module_dir"

   # Now we need to figure out what precompiled version of PSOL to build
   # ngx_pagespeed against.
   if "$DRYRUN"; then
     psol_url="https://psol.example.com/cant-get-psol-version-in-dry-run.tar.gz"
   elif [ -e PSOL_BINARY_URL ]; then
     # Releases after 1.11.33.4 there is a PSOL_BINARY_URL file that tells us
     # where to look.
     psol_url="$(scripts/format_binary_url.sh PSOL_BINARY_URL)"
     if [[ "$psol_url" != https://* ]]; then
       fail "Got bad psol binary location information: $psol_url"
     fi
   else
     # For past releases we have to grep it from the config file.  The url has
     # always looked like this, and the config file has contained it since before
     # we started tagging our ngx_pagespeed releases.
     psol_url="$(
       grep -o "https://dl.google.com/dl/page-speed/psol/[0-9.]*.tar.gz" config)"
     if [ -z "$psol_url" ]; then
       fail "Couldn't find PSOL url in $PWD/config"
     fi
   fi

   run wget "$psol_url"
   echo "Extracting PSOL..."
   run tar -xzf $(basename "$psol_url")  # extracts to psol/

   if "$DYNAMIC_MODULE"; then
     add_module="--add-dynamic-module=$nps_module_dir"
   else
     add_module="--add-module=$nps_module_dir"
   fi
   configure_args=("$add_module" "${extra_flags[@]}")

   echo
   if [ -z "$NGINX_VERSION" ]; then
     # They didn't specify an nginx version, so we're just preparing the
     # module for them to install.
     echo "ngx_pagespeed is ready to be built against nginx."
     echo "When running ./configure pass in:"
     echo "  $(quote_arguments "${configure_args[@]}")"
     if [ ${#extra_flags[@]} -eq 0 ]; then
       echo "If this is for integration with an already-built nginx, make sure"
       echo "to include any other arguments you originally passed to ./configure"
       echo "You can see these with 'nginx -V'."
     else
       echo "Note: because we need to set $(quote_arguments "${extra_flags[@]}")"
       echo "on this platform, if you want to integrate ngx_pagespeed with an"
       echo "already-built nginx you're going to need to rebuild your nginx with"
       echo "those flags set."
     fi
   else
     # Download and build nginx.
     nginx_leaf="nginx-${NGINX_VERSION}.tar.gz"
     nginx_fname="$TEMPDIR/$nginx_leaf"
     run wget "http://nginx.org/download/$nginx_leaf" -O "$nginx_fname"
     nginx_dir="$BUILDDIR/nginx-${NGINX_VERSION}/"
     delete_if_already_exists "$nginx_dir"
     echo "Extracting nginx..."
     run tar -xzf "$nginx_fname" --directory "$BUILDDIR"
     "$DRYRUN" || cd "$nginx_dir"

     configure=("./configure" "${configure_args[@]}")
     echo "About to build nginx.  Do you have any additional ./configure"
     echo "arguments you would like to set?  For example, if you would like"
     echo "to build nginx with https support give --with-http_ssl_module"
     echo "If you don't have any, just press enter."
     read -p "> " additional_configure_args
     if [ -n "$additional_configure_args" ]; then
       # Split additional_configure_args respecting any internal quotation.
       # Otherwise things like --with-cc-opt='-foo -bar' won't work.
       eval additional_configure_args=("$additional_configure_args")
       configure=("${configure[@]}" "${additional_configure_args[@]}")
     fi
     echo "About to configure nginx with:"
     echo "   $(quote_arguments "${configure[@]}")"
     continue_or_exit "Does this look right?"
     run "${configure[@]}"

     continue_or_exit "Build nginx?"
     run make

     continue_or_exit "Install nginx?"
     run sudo make install

     echo
     if "$DYNAMIC_MODULE"; then
       echo "Nginx installed with ngx_pagespeed support available as a"
       echo "loadable module."
       echo
       echo "To load the ngx_pagespeed module, you'll need to add:"
       echo "  load_module \"modules/ngx_pagespeed.so\";"
       echo "at the top of your main nginx configuration file."
     else
       echo "Nginx installed with ngx_pagespeed support compiled-in."
     fi
     echo
     echo "If this is a new installation you probably need an init script to"
     echo "manage starting and stopping the nginx service.  See:"
     echo "  http://wiki.nginx.org/InitScripts"
     echo
     echo "You'll also need to configure ngx_pagespeed if you haven't yet:"
     echo "  https://developers.google.com/speed/pagespeed/module/configuration"
   fi
   if "$DRYRUN"; then
     echo "[this was a dry run; your system is unchanged]"
   fi
 }

 # Start running things from a call at the end so if this script is executed
 # after a partial download it doesn't do anything.
 build_ngx_pagespeed "$@"
	#!/bin/bash

	function usage() {
	echo "
	Usage: build_ngx_pagespeed.sh [options]

	Installs ngx_pagespeed and its dependencies. Can optionally build and install
	nginx as well.

	Options:
	-v, --ngx-pagespeed-version <ngx_pagespeed version>
	What version of ngx_pagespeed to build. Valid options include:
	* latest-beta
	* latest-stable
	* a version number, such as 1.11.33.4

	If you don't specify a version, defaults to latest-stable.

	-n, --nginx-version <nginx version>
	What version of nginx to build. If not set, this script only prepares the
	ngx_pagespeed module, and expects you to handle including it when you
	build nginx.

	If you pass in 'latest' then this script scrapes the nginx download page
	and attempts to determine the latest version automatically.

	-m, --dynamic-module
	Build ngx_pagespeed as a dynamic module.

	-b, --builddir <directory>
	Where to build. Defaults to \$HOME.

	-p, --no-deps-check
	By default, this script checks for the packages it depends on and tries to
	install them. If you have installed dependencies from source or are on a
	non-deb non-rpm system, this won't work. In that case, install the
	dependencies yourself and pass --no-deps-check.

	-d, --dryrun
	Don't make any changes to the system, just print what changes you
	would have made.

	-h, --help
	Print this message and exit."
	}

	# Prints an error message and exits with an error code.
	function fail() {
	local error_message="$@"
	echo "$@" >&2

	# Normally I'd use $0 in "usage" here, but since most people will be running
	# this via curl, that wouldn't actually give something useful.
	echo >&2
	echo "For usage information, run this script with --help" >&2
	exit 1
	}

	# Intended to be called as:
	# bash <(curl dl.google.com/.../build_ngx_pagespeed.sh) <args>

	# If we set -e or -u then users of this script will see it silently exit on
	# failure. Instead we need to check the exit status of each command manually.
	# The run function handles exit-status checking for system-changing commands.
	# Additionally, this allows us to easily have a dryrun mode where we don't
	# actually make any changes.
	function run() {
	if "$DRYRUN"; then
	echo "would run $@"
	else
	if ! "$@"; then
	echo "Failure running $@, exiting."
	exit 1
	fi
	fi
	}

	function redhat_is_installed() {
	local package_name="$1"
	rpm -qa $package_name \| grep -q .
	}

	function debian_is_installed() {
	local package_name="$1"
	dpkg -l $package_name \| grep ^ii \| grep -q .
	}

	function version_sort() {
	# We'd rather use sort -V, but that's not available on Centos 5. This works
	# for versions in the form A.B.C.D or shorter, which is enough for our use.
	sort -t '.' -k 1,1 -k 2,2 -k 3,3 -k 4,4 -g
	}

	# Compare two numeric versions in the form "A.B.C". Works with version numbers
	# having up to four components, since that's enough to handle both nginx (3) and
	# ngx_pagespeed (4).
	function version_older_than() {
	local test_version="$1"
	local compare_to="$2"

	local older_version=$(echo $@ \| tr ' ' '\n' \| version_sort \| head -n 1)
	test "$older_version" != "$compare_to"
	}

	function determine_latest_nginx_version() {
	# Scrape nginx's download page to try to find the most recent nginx version.

	nginx_download_url="https://nginx.org/en/download.html"
	function report_error() {
	fail "
	Couldn't automatically determine the latest nginx version: failed to $@
	$nginx_download_url"
	}

	nginx_download_page=$(curl -sS --fail "$nginx_download_url") \|\| \
	report_error "download"

	download_refs=$(echo "$nginx_download_page" \| \
	grep -o '/download/nginx-[0-9.]*[.]tar[.]gz') \|\| \
	report_error "parse"

	versions_available=$(echo "$download_refs" \| \
	sed -e 's~^/download/nginx-~~' -e 's~\.tar\.gz$~~') \|\| \
	report_error "extract versions from"

	latest_version=$(echo "$versions_available" \| version_sort \| tail -n 1) \|\| \
	report_error "determine latest version from"

	if version_older_than "$latest_version" "1.11.4"; then
	fail "
	Expected the latest version of nginx to be at least 1.11.4 but found
	$latest_version on $nginx_download_url"
	fi

	echo "$latest_version"
	}

	# Usage:
	# install_dependencies install_pkg_cmd is_pkg_installed_cmd dep1 dep2 ...
	#
	# install_pkg_cmd is a command to install a dependency
	# is_pkg_installed_cmd is a command that returns true if the dependency is
	# already installed
	# each dependency is a package name
	function install_dependencies() {
	local install_pkg_cmd="$1"
	local is_pkg_installed_cmd="$2"
	shift 2

	local missing_dependencies=""

	for package_name in "$@"; do
	if ! $is_pkg_installed_cmd $package_name; then
	missing_dependencies+="$package_name "
	fi
	done
	if [ -n "$missing_dependencies" ]; then
	echo "Detected that we're missing the following depencencies:"
	echo " $missing_dependencies"
	echo "Installing them:"
	run sudo $install_pkg_cmd $missing_dependencies
	fi
	}

	function gcc_too_old() {
	# We need gcc >= 4.8
	local gcc_major_version=$(gcc -dumpversion \| awk -F. '{print $1}')
	if [ "$gcc_major_version" -lt 4 ]; then
	return 0 # too old
	elif [ "$gcc_major_version" -gt 4 ]; then
	return 1 # plenty new
	fi
	# It's gcc 4.x, check if x >= 8:
	local gcc_minor_version=$(gcc -dumpversion \| awk -F. '{print $2}')
	test "$gcc_minor_version" -lt 8
	}

	function continue_or_exit() {
	local prompt="$1"
	read -p "$prompt [Y/n] " yn
	if [[ "$yn" == N* \|\| "$yn" == n* ]]; then
	echo "Cancelled."
	exit 0
	fi
	}

	# If a string is very simple we don't need to quote it. But we should quote
	# everything else to be safe.
	function needs_quoting() {
	echo "$@" \| grep -q '[^a-zA-Z0-9./_=-]'
	}

	function escape_for_quotes() {
	echo "$@" \| sed -e 's~\\~\\\\~g' -e "s~'~\\\\'~g"
	}

	function quote_arguments() {
	local argument_str=""
	for argument in "$@"; do
	if [ -n "$argument_str" ]; then
	argument_str+=" "
	fi
	if needs_quoting "$argument"; then
	argument="'$(escape_for_quotes "$argument")'"
	fi
	argument_str+="$argument"
	done
	echo "$argument_str"
	}

	function build_ngx_pagespeed() {
	getopt --test
	if [ "$?" != 4 ]; then
	# Even Centos 5 and Ubuntu 10 LTS have new-style getopt, so I don't expect
	# this to be hit in practice on systems that are actually able to run
	# PageSpeed.
	fail "Your version of getopt is too old. Exiting with no changes made."
	fi

	opts=$(getopt -o v:n:mb:pdh \
	--longoptions ngx-pagespeed-version:,nginx-version:,dynamic-module \
	--longoptions buildir:,no-deps-check,dryrun,help \
	-n "$(basename "$0")" -- "$@")
	if [ $? != 0 ]; then
	usage
	exit 1
	fi
	eval set -- "$opts"

	NPS_VERSION="latest-stable"
	NGINX_VERSION=""
	BUILDDIR="$HOME"
	DO_DEPS_CHECK=true
	DRYRUN=false
	DYNAMIC_MODULE=false
	while true; do
	case "$1" in
	-v \| --ngx-pagespeed-version) shift
	NPS_VERSION="$1"
	shift
	;;
	-n \| --nginx-version) shift
	NGINX_VERSION="$1"
	shift
	;;
	-m \| --dynamic-module) shift
	DYNAMIC_MODULE=true
	;;
	-b \| --builddir) shift
	BUILDDIR="$1"
	shift
	;;
	-p \| --no-deps-check) shift
	DO_DEPS_CHECK=false
	;;
	-d \| --dryrun) shift
	DRYRUN="true"
	;;
	-h \| --help) shift
	usage
	exit 0
	;;
	--) shift
	break
	;;
	*)
	echo "Invalid argument: $1"
	usage
	exit 1
	;;
	esac
	done

	if [ ! -d "$BUILDDIR" ]; then
	fail "Told to build in $BUILDDIR, but that directory doesn't exist."
	fi

	if [ "$NGINX_VERSION" = "latest" ]; then
	# When this function fails it prints the debugging information needed first
	# to stderr.
	NGINX_VERSION=$(determine_latest_nginx_version) \|\| exit 1
	fi

	if "$DYNAMIC_MODULE"; then
	# Check that ngx_pagespeed and nginx are recent enough to support dynamic
	# modules.
	if version_older_than "$NPS_VERSION" "1.10.33.5"; then
	fail "
	You're trying to build ngx_pagespeed $NPS_VERSION as a dynamic module, but
	ngx_pagespeed didn't add support for dynamic modules until 1.10.33.5."
	fi

	if [ ! -z "NGINX_VERSION" ]; then
	if version_older_than "$NGINX_VERSION" "1.9.13"; then
	fail "
	You're trying to build nginx $NGINX_VERSION as a dynamic module but nginx didn't
	add support for dynamic modules in a way compatible with ngx_pagespeed until
	1.9.13."
	fi
	fi
	fi

	if "$DRYRUN"; then
	TEMPDIR="/tmp/output-of-mktemp"
	else
	TEMPDIR=$(mktemp -d)
	function cleanup_tempdir {
	rm -rf "$TEMPDIR"
	}
	trap cleanup_tempdir EXIT
	fi

	extra_flags=()
	# Now make sure our dependencies are installed.
	if "$DO_DEPS_CHECK"; then
	if [ -f /etc/debian_version ]; then
	echo "Detected debian-based distro."

	install_dependencies "apt-get install" debian_is_installed \
	"build-essential zlib1g-dev libpcre3 libpcre3-dev unzip"

	if gcc_too_old; then
	if [ ! -e /usr/lib/gcc-mozilla/bin/gcc ]; then
	echo "Detected that gcc is older than 4.8. Installing gcc-mozilla"
	echo "which installs gcc-4.8 into /usr/lib/gcc-mozilla/ and doesn't"
	echo "affect your global gcc installation."
	run sudo apt-get install gcc-mozilla
	fi

	extra_flags=("--with-cc=/usr/lib/gcc-mozilla/bin/gcc" \
	"--with-ld-opt=-static-libstdc++")
	fi

	elif [ -f /etc/redhat-release ]; then
	echo "Detected redhat-based distro."

	install_dependencies "yum install" redhat_is_installed \
	"gcc-c++ pcre-devel zlib-devel make unzip wget"
	if gcc_too_old; then
	if [ ! -e /opt/rh/devtoolset-2/root/usr/bin/gcc ]; then
	redhat_major_version=$(
	cat /etc/redhat-release \| grep -o -E '[0-9]+' \| head -n 1)
	if [ "$redhat_major_version" == 5 ]; then
	slc_version=5
	elif [ "$redhat_major_version" == 6 ]; then
	slc_version=6
	else
	fail "
	Unexpected major version $redhat_major_version in /etc/redhat-release:
	$(cat /etc/redhat-release) Expected 5 or 6."
	fi

	echo "Detected that gcc is older than 4.8. Scientific Linux provides"
	echo "a gcc package that installs gcc-4.8 into /opt/ and doesn't"
	echo "affect your global gcc installation."
	slc_key="https://linux.web.cern.ch/linux/scientific6/docs/repository/"
	slc_key+="cern/slc6X/i386/RPM-GPG-KEY-cern"
	slc_key_out="$TEMPDIR/RPM-GPG-KEY-cern"
	run sudo wget "$slc_key" -O "$slc_key_out"
	run sudo rpm --import "$slc_key_out"

	repo_fname="/etc/yum.repos.d/slc${slc_version}-devtoolset.repo"
	if [ -e "$repo_fname" ]; then
	fail "Expected $repo_fname not to exist; aborting."
	fi

	repo_url="https://linux.web.cern.ch/linux/scientific${slc_version}/"
	repo_url+="/docs/repository/cern/devtoolset/"
	repo_url+="slc${slc_version}-devtoolset.repo"
	run sudo wget -O "$repo_fname" "$repo_url"
	run sudo yum install devtoolset-2-gcc-c++ devtoolset-2-binutils
	fi
	extra_flags=("--with-cc=/opt/rh/devtoolset-2/root/usr/bin/gcc")
	fi
	else
	fail "
	This doesn't appear to be a deb-based distro or an rpm-based one. Not going to
	be able to install dependencies. Please install dependencies manually and rerun
	with --no-deps-check."
	fi
	echo "Dependencies are all set."
	else
	echo "Not checking whether dependencies are installed."
	fi

	function delete_if_already_exists() {
	if "$DRYRUN"; then return; fi

	local directory="$1"
	if [ -d "$directory" ]; then
	if [ ${#directory} -lt 8 ]; then
	fail "
	Not deleting $directory; name is suspiciously short. Something is wrong."
	exit 1
	fi

	continue_or_exit "OK to delete $directory?"
	run rm -rf "$directory"
	fi
	}

	nps_baseurl="https://github.com/pagespeed/ngx_pagespeed/archive"
	# In general, the zip github builds for tag foo unzips to ngx_pagespeed-foo,
	# but it looks like they special case vVERSION tags to ngx_pagespeed-VERSION.
	if [[ "$NPS_VERSION" =~ ^[0-9][.][0-9][.][0-9][.][0-9]$ ]]; then
	# We've been given a numeric version number. This has an associated tag in
	# the form vVERSION-beta.
	nps_url_fname="v${NPS_VERSION}-beta"
	nps_downloaded_fname="ngx_pagespeed-${NPS_VERSION}-beta"
	else
	# We've been given a tag name, like latest-beta. Download that directly.
	nps_url_fname="$NPS_VERSION"
	nps_downloaded_fname="ngx_pagespeed-${NPS_VERSION}"
	fi

	nps_downloaded="$TEMPDIR/$nps_downloaded_fname.zip"
	run wget "$nps_baseurl/$nps_url_fname.zip" -O "$nps_downloaded"
	nps_module_dir="$BUILDDIR/$nps_downloaded_fname"
	delete_if_already_exists "$nps_module_dir"
	echo "Extracting ngx_pagespeed..."
	run unzip -q "$nps_downloaded" -d "$BUILDDIR"
	run cd "$nps_module_dir"

	# Now we need to figure out what precompiled version of PSOL to build
	# ngx_pagespeed against.
	if "$DRYRUN"; then
	psol_url="https://psol.example.com/cant-get-psol-version-in-dry-run.tar.gz"
	elif [ -e PSOL_BINARY_URL ]; then
	# Releases after 1.11.33.4 there is a PSOL_BINARY_URL file that tells us
	# where to look.
	psol_url="$(scripts/format_binary_url.sh PSOL_BINARY_URL)"
	if [[ "$psol_url" != https://* ]]; then
	fail "Got bad psol binary location information: $psol_url"
	fi
	else
	# For past releases we have to grep it from the config file. The url has
	# always looked like this, and the config file has contained it since before
	# we started tagging our ngx_pagespeed releases.
	psol_url="$(
	grep -o "https://dl.google.com/dl/page-speed/psol/[0-9.]*.tar.gz" config)"
	if [ -z "$psol_url" ]; then
	fail "Couldn't find PSOL url in $PWD/config"
	fi
	fi

	run wget "$psol_url"
	echo "Extracting PSOL..."
	run tar -xzf $(basename "$psol_url") # extracts to psol/

	if "$DYNAMIC_MODULE"; then
	add_module="--add-dynamic-module=$nps_module_dir"
	else
	add_module="--add-module=$nps_module_dir"
	fi
	configure_args=("$add_module" "${extra_flags[@]}")

	echo
	if [ -z "$NGINX_VERSION" ]; then
	# They didn't specify an nginx version, so we're just preparing the
	# module for them to install.
	echo "ngx_pagespeed is ready to be built against nginx."
	echo "When running ./configure pass in:"
	echo " $(quote_arguments "${configure_args[@]}")"
	if [ ${#extra_flags[@]} -eq 0 ]; then
	echo "If this is for integration with an already-built nginx, make sure"
	echo "to include any other arguments you originally passed to ./configure"
	echo "You can see these with 'nginx -V'."
	else
	echo "Note: because we need to set $(quote_arguments "${extra_flags[@]}")"
	echo "on this platform, if you want to integrate ngx_pagespeed with an"
	echo "already-built nginx you're going to need to rebuild your nginx with"
	echo "those flags set."
	fi
	else
	# Download and build nginx.
	nginx_leaf="nginx-${NGINX_VERSION}.tar.gz"
	nginx_fname="$TEMPDIR/$nginx_leaf"
	run wget "http://nginx.org/download/$nginx_leaf" -O "$nginx_fname"
	nginx_dir="$BUILDDIR/nginx-${NGINX_VERSION}/"
	delete_if_already_exists "$nginx_dir"
	echo "Extracting nginx..."
	run tar -xzf "$nginx_fname" --directory "$BUILDDIR"
	"$DRYRUN" \|\| cd "$nginx_dir"

	configure=("./configure" "${configure_args[@]}")
	echo "About to build nginx. Do you have any additional ./configure"
	echo "arguments you would like to set? For example, if you would like"
	echo "to build nginx with https support give --with-http_ssl_module"
	echo "If you don't have any, just press enter."
	read -p "> " additional_configure_args
	if [ -n "$additional_configure_args" ]; then
	# Split additional_configure_args respecting any internal quotation.
	# Otherwise things like --with-cc-opt='-foo -bar' won't work.
	eval additional_configure_args=("$additional_configure_args")
	configure=("${configure[@]}" "${additional_configure_args[@]}")
	fi
	echo "About to configure nginx with:"
	echo " $(quote_arguments "${configure[@]}")"
	continue_or_exit "Does this look right?"
	run "${configure[@]}"

	continue_or_exit "Build nginx?"
	run make

	continue_or_exit "Install nginx?"
	run sudo make install

	echo
	if "$DYNAMIC_MODULE"; then
	echo "Nginx installed with ngx_pagespeed support available as a"
	echo "loadable module."
	echo
	echo "To load the ngx_pagespeed module, you'll need to add:"
	echo " load_module \"modules/ngx_pagespeed.so\";"
	echo "at the top of your main nginx configuration file."
	else
	echo "Nginx installed with ngx_pagespeed support compiled-in."
	fi
	echo
	echo "If this is a new installation you probably need an init script to"
	echo "manage starting and stopping the nginx service. See:"
	echo " http://wiki.nginx.org/InitScripts"
	echo
	echo "You'll also need to configure ngx_pagespeed if you haven't yet:"
	echo " https://developers.google.com/speed/pagespeed/module/configuration"
	fi
	if "$DRYRUN"; then
	echo "[this was a dry run; your system is unchanged]"
	fi
	}

	# Start running things from a call at the end so if this script is executed
	# after a partial download it doesn't do anything.
	build_ngx_pagespeed "$@"