TCP proxy with netcat

This is the simplest proxy for HTTP.

mkfifo /tmp/fifo
nc -lk -p 8080 </tmp/fifo | nc www.noah.org 80 >/tmp/fifo

Note that this will not work on virtual web sites. Web servers use the Host request header field to determine which virtual web site to serve. If Host is not set correctly then the brower

Site Temporarily Unavailable
We apologize for the inconvenience. Please contact the webmaster/ tech support immediately to have them rectify this.
error id: "bad_httpd_conf"

This creates a primitive HTTP proxy with logging. It rewrites the Host: field in the HTTP request header to satisfy HTTP servers that use the Host: header to decide which virtual web site to serve.

mkfifo /tmp/fifo
nc -lk -p 8080 </tmp/fifo | sed -u -e 's/^Host.*/Host: www.noah.org/' | tee -a http_request.log | nc www.noah.org 80 | tee -a http_response.log >/tmp/fifo

mkfifo /tmp/fifo
nc -lk -p 8080 </tmp/fifo | sed -u -e 's/^Host.*/Host: www.noah.org/' | tee -a http_request.log | nc www.noah.org 80 | tee -a http_response.log >/tmp/fifo

mkfifo /tmp/fifo
nc -q -1 -l -p 8080 </tmp/fifo | sed -u -e 's/^Host:.*/Host: www.noah.org/' -e '/^If-None-Match:.*/d' -e '/^If-Modified-Since:.*/d' -e '/^Connection:.*/d' -e '/^Accept-Encoding:.*/d' | tee -i -a http_request.log | nc -q -1 www.noah.org 80 | sed -u -e 's/noah.org/localhost/i' | tee -i -a http_response.log >/tmp/fifo