new url_to_id and added dry-run in burrow

README.md

@@ -0,0 +1,29 @@
+## Burrow-The-Burrows
+
+A Gopher burrower in a shell script. By using `burrow` and a bit of
+plumbing you can get all the links in a Gopher MENU, recursively visit
+all the available subdirs, and create a directed graph of the visited
+selectors.
+
+`burrow` takes as input a gopher identifier, as generated by
+`url_to_id`, which is considered a gophermap, and provides on stdout the
+list of menu selectors found in that document. `burrow` will also dump
+on stderr the list of all the edges (to any kind of selector) found in
+that page, in the format: 
+
+	src_SHA256 dst_SHA256
+
+where `src_SHA256` is the SHA256 of the source selector (the current
+document), while `dst_SHA256` is the destination selector (the pointed
+document).
+
+To start a crawl, one can do something like:
+
+```
+	$ ./url_to_id  gopher://your.gopher.url/ > ids
+	$ tail -f ids | parallel -j2 './burrow {}' 2>> graph.txt | tee -a ids >/dev/null &
+``` 
+
+Notice that `burrow` will create a certain number of folders in the
+current directory, used to keep track of the selectors that have been
+already retrieved.

burrow

@@ -7,6 +7,19 @@
 ###
 ### where SHA256 is the SHA256SUM of "1|SELECTOR|HOST|PORT"
 ###
+### *** DRY RUN ***
+###
+### If run as burrow?* (i.e., "burrow" followed by at least one 
+### character), burrow will run in DRY MODE, i.e., it will just check
+###  if the id provided as input exists, and then exit.
+###
+###------------------------------------------------
+###
+### (C) Vincenzo 'KatolaZ' Nicosia <katolaz@freaknet.org>
+###
+### Use, modify, redistribute under the terms of the GNU General 
+### Public License version 3 or, at your option, any other version.
+### 
 ## function
 get_dirs(){
 	src_id="$1"
@@ -56,7 +69,7 @@ retrieve_selector(){
 check_selector_present(){
 	sel_id="$1"
 	sel_dir="$(echo ${sel_id} | cut -c -2)"
-	[ -d "${sel_dir}" -a -f "${sel_dir}/${sel_id}" ] && exit
+	[ -d "${sel_dir}" -a -f "${sel_dir}/${sel_id}" ] && echo "${SRC}" >>present && exit
 ##	{
 	## if at least one of the neighbours of sel_id is missing, cat the entire list of
         ## neighbours to be re-visited and exit
@@ -69,6 +82,8 @@ check_selector_present(){
 	[ ! -d "${sel_dir}" ] && mkdir -p "${sel_dir}"
 }
 
+[ $# -lt 1 ] && echo "Usage: $0 <gopherlink>" && exit 1
+
 
 SRC="$1"
 
@@ -78,5 +93,9 @@ check_selector_present "${src_id}"
 
 echo "selector ${src_id} not found" >> logfile.txt
 
-retrieve_selector "$SRC" | sed -r -e 's/\t/|/g' | get_dirs "${src_id}"
+MYNAME=$(basename $0)
+
+if [ -z "${MYNAME##burrow}" ]; then  
+	retrieve_selector "$SRC" | sed -r -e 's/\t/|/g' | get_dirs "${src_id}"
+fi
  

url_to_id

@@ -1,15 +1,25 @@
 #!/bin/sh
 
-## get a selector in gph format:
+##
+## Get a gopherlink in the format:
+##
+##   gopher://domain.org:port/*/my/cool/selector
+##
+## or a selector in gph format:
 ##
 ##   [TYPE|SEL|HOST|PORT]
 ##
-## and print on output the corresponding selectorid:
+## and print on output the corresponding "unique" selectorid:
 ##
 ##   TYPE|SEL|HOST|PORT|SHA256
 ## 
 ## which is understood by `burrow`
 
+
+### 
+### get a selector in gph format and transform it in a selectorid
+###
+## function
 gph_to_id(){
 	gph="$( echo $1| sed 's/\[//g;s/\]//g')"
 	OLDIFS=$IFS
@@ -20,4 +30,45 @@ gph_to_id(){
 	IFS="$OLDIFS"
 }
 
-gph_to_id "$1"
+###
+### Get a gopherurl and transform it in a selectorid
+###
+## function
+gopherurl_to_id(){
+	URL="$(echo $1 | sed 's,gopher://,,g')"
+	hostport=$(echo "$URL" | cut -d "/" -f 1)
+	host="$(echo $hostport | cut -d ":" -f 1)"
+	port="$(echo $hostport | cut -s -d ":" -f 2)"
+	[ -z "$port" ] && port='70'
+	type=$(echo "$URL" | cut -s -d "/" -f 2)
+	[ -z "$type" ] && {
+		type='1'
+		sel="/"
+		gph_to_id "[${type}|${sel}|${host}|$port]"
+		exit 0
+	}
+	[ -n "${type#?}" ] && echo "Invalid Gopher URL" >&2 && exit 1
+	## Check if type is a valid one
+	type="$(echo $type | sed -n '/^[0-9ITghis+]$/p')"
+	[ -z "${type}" ] && echo "Invalid Gopher URL" >&2 && exit 1
+	sel=/$(echo "$URL" | cut -s -d "/" -f 3-)
+	gph_to_id "[${type}|${sel}|${host}|$port]"
+	
+}
+
+
+
+[ $# -lt 1 ] && echo "Usage: $0 <gopherurl>" && echo "       $0 <gphselector>"  && exit 1
+
+
+[ -n "$(echo $1 | sed -n '/^gopher:\/\//p')" ] && {
+	gopherurl_to_id "$1" 
+	exit 0
+} 
+
+[ -n "$(echo $1 | sed -n '/^\[.*\]$/p')" ] && {
+	gph_to_id "$1"
+	exit 0
+}
+echo "No valid URL or gph selector provided" >&2
+exit 1