What does this do?

# ensure that there is only one -O in CFLAGS and that it is -O2

On Mon, Mar 23, 2009 at 1:42 PM, Mark Alan <varia@e-healthexpert.org> wrote:
> I am attaching the procedure that we use to to always have the latest nginx
> version in Ubuntu/Debian.
>
> M.
>
> ## -- start-of-procedure
>
> # Install the current Nginx (Ubuntu 8.10 = Nginx/0.6.34 @ backports)
> sudo aptitude -R install nginx= ; # the ending = means install & hold to
>  prevent automatic upgrades
>
> # install needed ubuntu/debian compiling tools
> sudo aptitude -R install build-essential libpcre3 libpcre3-dev libpcrecpp0
> libssl-dev zlib1g-dev
>
> # build & replace by the latest "debianized" Nginx 0.7.44
> test -x $HOME/src/ || mkdir -p $HOME/src/ && cd $HOME/src/
> # nginx's latest version: http://sysoev.ru/nginx/download.html
> wget http://sysoev.ru/nginx/nginx-0.7.44.tar.gz
> tar zxvf nginx-0.7.44.tar.gz
>
> cd nginx-0.7.44
> ./configure --prefix=/etc/nginx \
>        --sbin-path=/usr/sbin/nginx \
>        --conf-path=/etc/nginx/nginx.conf \
>        --error-log-path=/var/log/nginx/error.log \
>        --pid-path=/var/run/nginx.pid \
>        --lock-path=/var/lock/nginx.lock \
>        --user=www-data \
>        --group=www-data \
>        --http-log-path=/var/log/nginx/access.log \
>        --http-client-body-temp-path=/var/lib/nginx/body \
>        --http-proxy-temp-path=/var/lib/nginx/proxy \
>        --http-fastcgi-temp-path=/var/lib/nginx/fastcgi \
>        --with-cc-opt=-O2 \
>        --with-http_gzip_static_module \
>        --with-http_ssl_module
>
> # ensure that there is only one -O in CFLAGS and that it is -O2
> sed -i '/CFLAGS/s/ \-O //g' objs/Makefile
>
> make
>
> # debian policy: use 'install' instead of 'cp' or 'mv'
> sudo /usr/bin/install -s -m 755 -o root objs/nginx /usr/sbin/nginx.new &&
> sudo mv /usr/sbin/nginx /usr/sbin/nginx.old-"$(date +%Y%m%d-%H%M-%S)" &&
> sudo mv -v /usr/sbin/nginx.new /usr/sbin/nginx
>
> sudo kill -15 $(pidof nginx) ; sudo /etc/init.d/nginx restart
>
> ## -- end-of-procedure
>
>