Paul Buchheit: Webserver in bash

Paul Buchheit

Friday, April 13, 2007

Webserver in bash

And not using perl or any of that fancy stuff. It's the inane things that keep me awake at night.

Getting nc to behave turned out to be the most difficult part. It won't exit until both ends of the connection are closed. Correction, making blogger not mangle this code was the most difficult part.

#!/bin/bash

web.sh -- http://localhost:9000/hello?world

RESP=/tmp/webresp
[ -p $RESP ] || mkfifo $RESP

while true ; do
( cat $RESP ) | nc -l -p 9000 | (
REQ=while read L && [ " " "<" "$L" ] ; do echo "$L" ; done
echo "[date '+%Y-%m-%d %H:%M:%S'] $REQ" | head -1
cat >$RESP <<EOF
HTTP/1.0 200 OK
Cache-Control: private
Content-Type: text/plain
Server: bash/2.0
Connection: Close
Content-Length: ${#REQ}

$REQ
EOF
)
done

Update: Fixed script so that it also work in Linux, where tr lacks the -u option.

Posted by Paul Buchheit at 5:53 PM

6 comments:

abbot said...
It should be like this to behave with both gnu and bsd utils:
( cat $RESP ) | nc -l 9000 | sed -ue 's/r//g' | (: 2:29 PM

Paul Buchheit said...
Thanks abbot, but OSX sed doesn't support -u. I found a way to get rid of tr instead.: 3:53 PM

brett said...

well that wasted a bit of my day.
how about a version that takes a document root and serves html files:

#!/bin/bash

pass in document root as first arg

web.sh ~/Sites/test

DOC_ROOT=$1
RESP=/tmp/webresp
[ -p $RESP ] || mkfifo $RESP

while true ; do
( cat $RESP ) | nc -l -p 9000 | tr -ud 'r' | (
REQ=while read L && [ -n "$L" ] ; do echo "$L" ; done
SERV_PATH=echo "$REQ" | head -1 | cut -f2 -d" "
FULL_PATH="$DOC_ROOT$SERV_PATH"
echo $FULL_PATH
if [ -f "$FULL_PATH" ]; then
RESP_BODY=cat $FULL_PATH
RESP_CODE="200 OK"
else
RESP_BODY="not found

$REQ"
RESP_CODE="404 NOT FOUND"
fi
echo "[date '+%Y-%m-%d %H:%M:%S'] $REQ" | head -1
cat >$RESP <<EOF
HTTP/1.0 $RESP_CODE
Cache-Control: private
Content-Type: text/html
Server: bash/2.0
Connection: Close
Content-Length: ${#RESP_BODY}