added preliminary support for CGI

gosher

@@ -19,11 +19,11 @@
 ##
 ##  gosher is a simple Gopher server in a POSIX shell script:
 ##
-##     $ ./gosher [<PORT> [<GOPHERDIR>]
-##
-##  If PORT is not specified, the default is 70. If GOPHERDIR is not
-##  specified, "./" is assumed
+##     $ ./gosher [<GOPHERDIR> [<HOSTNAME> [<PORT>]]]
 ##
+##  If GOPHERDIR is not specified, "./" is assumed. 
+##  If HOSTNAME is not specified, "localhost" is used.
+##  If PORT is not specified, the default port "70" is used.
 ##
 ##  (c) 2018 Vincenzo 'KatolaZ' Nicosia <katolaz@freaknet.org>
 ##
@@ -82,9 +82,9 @@ NETCAT=$(which "$NETCAT")
 
 if [ -z "${MYNAME#gosher}" ]; then
 	## we are called as gosher -- launch the server
-
-	PORT=${1:-70}
-	GOPHERDIR=${2:-"./"}
+	GOPHERDIR=${1:-"./"}
+	HOSTNAME=${2:-"localhost"}
+	PORT=${3:-70}
 	
 	[ ! -f "${NETCAT}" ] || [ ! -x "${NETCAT}" ] && {
 		echo "Wrong NETCAT -- Exiting" >&2
@@ -101,7 +101,9 @@ if [ -z "${MYNAME#gosher}" ]; then
 # shellcheck disable=SC2050
 			while [ 1 -eq 1 ]; do
 # shellcheck disable=SC2094
-				${GOSHER_SERVE} "${GOPHERDIR}" <"$INF" | ${NETCAT} -vvvvv -l -p "${PORT}" >"$INF"
+				${GOSHER_SERVE} "${GOPHERDIR}" \
+				   "${HOSTNAME}" "${PORT}" <"$INF" |\
+				    ${NETCAT} -vvvvv -l -p "${PORT}" >"$INF"
 			done
 			rm -f $INF
 			exit 0
@@ -109,7 +111,8 @@ if [ -z "${MYNAME#gosher}" ]; then
 		[ "$STYLE" = 'fork' ] && {
 # shellcheck disable=SC2050
 			while [ 1 -eq 1 ]; do
-				${NETCAT} -vv -l -p "$PORT" -c "${GOSHER_SERVE} ${GOPHERDIR}"
+				${NETCAT} -vv -l -p "$PORT" -c \
+				   "${GOSHER_SERVE} ${GOPHERDIR} ${HOSTNAME} ${PORT}"
 			done
 			exit 0
 		}
@@ -197,10 +200,36 @@ EOF
 
 }
 
-
+### Serve a CGI -- Set the environment and run the corresponding script
+## function
+serve_cgi(){
+	script_name=$( echo "$1" | sed -r 's:^/+::')
+	query_string="$2"
+	echo "script_name: ${script_name}" >&2
+        GATEWAY_INTERFACE="CGI/1.1"
+        PATH_INFO="${script_name}"
+        PATH_TRANSLATED="${script_name}"
+        QUERY_STRING="${query_string}"
+        REMOTE_ADDR=
+        REMOTE_HOST="${REMOTE_ADDR}"
+        REQUEST_METHOD="GET"
+        SCRIPT_NAME="${script_name}"
+        SERVER_NAME="${HOSTNAME}"
+        SERVER_PORT="${PORT}"
+        SERVER_PROTOCOL="gopher/1.0"
+        SERVER_SOFTWARE="gosher"
+        ####X_GOPHER_SEARCH= search (See above.)
+	export GATEWAY_INTERFACE PATH_INFO PATH_TRANSLATED QUERY_STRING
+	export REMOTE_ADDR REMOTE_HOST REQUEST_METHOD SCRIPT_NAME 
+	export SERVER_NAME SERVER_PORT SERVER_PROTOCOL SERVER_SOFTWARE
+	${GOPHERDIR}${script_name} "" "${query_string}" "${HOSTNAME}" ${PORT}
+	exit 0
+}
 
 
 GOPHERDIR=${1:-"./"}
+HOSTNAME=${2:-"localhost"}
+PORT=${3:-"70"}
 
 read -r selector
 
@@ -213,10 +242,36 @@ selector=$(echo "$selector" | sed -r 's:\$.*::g;s:\r::g' )
 
 case $selector in
 	URL:*)
+		## it's a special URL selector
 		url=$(echo "$selector" | cut -d ":" -f 2-)
 		serve_redirect "$url"
         ;;
+	/?*.cgi*)
+		## it's a CGI
+		script_name=$(echo "$selector" | cut -d "?" -f 1)
+		query_string=$(echo "$selector" | cut -d "?" -f 2)
+		[ "${script_name}" = "${query_string}" ] && query_string=""
+		RP1=$(realpath "${GOPHERDIR}""${script_name}" || "")
+# shellcheck disable=SC2181
+		[ $? -eq 0 ] || invalid_selector "${selector}"
+		RP2=$(realpath "${GOPHERDIR}")"${script_name}"
+		RP2=$(echo "${RP2}" | sed -r 's/\/+/\//g')
+# shellcheck disable=SC2181
+		[ $? -eq 0 ] || invalid_selector "${selector}"
+		[ -n "$DEBUG" ] && {
+			echo "iRP1: ${RP1}"
+			echo "iRP2: ${RP2}"
+		}
+		
+		if [ "${RP1}" = "${RP2}" ]; then
+			[ -x "${RP1}" ] && {
+				serve_cgi "${script_name}" "${query_string}"
+			}
+		fi
+		invalid_selector "${selector}"
+	;;
 	/?*|"")
+		## it's a regular selector
 		RP1=$(realpath "${GOPHERDIR}"/"${selector}" || "")
 # shellcheck disable=SC2181
 		[ $? -eq 0 ] || invalid_selector "$selector"
@@ -243,6 +298,8 @@ case $selector in
 		invalid_selector "$selector"
 	;;
 	*)
+		## we don't know what it is -- try to default to a
+		## gophermap
 		[ -f "${GOPHERDIR}/gophermap" ] && serve_selector "${GOPHERDIR}/gophermap"
 		[ -f "${GOPHERDIR}/index.gph" ] && serve_index "${GOPHERDIR}/index.gph"
 		echo "got invalid selector: \"$selector\"" >&2