new config file on stderr + amend README

README.md

@@ -5,8 +5,8 @@
 configuration file and outputs the relevant selectors to be added to a
 gophermap. The list of selectors of updated phlogs is sorted in
 decreasing order of update time (meaning that more recent updates appear
-at the top of the list). `phrollo` also outputs an updaterd config file,
+at the top of the list). `phrollo` also prints on stderr an updaterd
-to be used for future calls.
+config file, to be used for future calls.
 
 `phrollo` detects updates by using `shasum -a 256`, i.e. by computing 
 a hash of the resource and comparing it with the hash obtained when the 
@@ -15,25 +15,23 @@ resource was last seen.
    Usage   
 ===========
 
-1) 
+Either :
 ```
 ./phrollo status.txt
 ```
-
+or:
-In this case, `phrollo` will put a new config file in `status.txt.new`,
-and output the sorted list of gopher selectors. The config file received
-on input will also be saved in `status.txt.bak`.
-2) 
 
 ```
- cat config.txt | ./phrollo
+ cat status.txt | ./phrollo
 ```
 
-In this case, the new config file will be put in `phrollo.out`, and
+will print the sorted list of gopher selectors on stdout, and the
-output the sorted list of gopher selectors.
+updated config file on stderr.
  
 IMPORTANT: The next time `phrollo` is run, it must be given the last
-config file generated.
+config file generated, so be sure to redirect stderr appropriately. A
+fully working example is given below.
+
 
    Configuration file   
 ========================
@@ -71,7 +69,13 @@ them with a "-" dash. Notice that fields are separated by actual TABs:
 -	KatolaZ	/~katolaz/phlog	republic.circumlunar.space	70	-
 ```
 
-Now we can feed this file to `phrollo` to get:
+Now we can feed this file to `phrollo`:
+
+```
+cat config.txt | ./phrollo 2> config_updated.txt > gophermap
+```
+
+and we will get the following output in `gophermap`:
 
 ```
 1(20190126) Alex Shroeder	/	alexschroeder.ch	70
@@ -83,8 +87,7 @@ Now we can feed this file to `phrollo` to get:
 ```
 
 which is a list of selectors corresponding to the phlogs specified in
-the config file. Moreover, `phrollo` will also create the updated 
+the config file, and the updated config file in config_updated.txt:
-config file `phrollo.out`:
 
 ```
 20190126	Tomasino	/phlog	gopher.black	70	bd141abfc29522e3e2b5d00f1a656212201ae5def60de90a7ce847cddeb6d0db
@@ -96,4 +99,18 @@ config file `phrollo.out`:
 ```
 
 Then, we can run `phrollo` again using the latest updated config file
-(i.e., `phrollo.out`) to detect updates.
+to detect updates and generate the new gophermap. It is possible to
+automate the update procedure by something like:
+
+```
+#!/bin/sh
+
+cp config.txt config.txt."$(date +%Y%m%d)"
+cat config.txt | ./phrollo 2> config.txt.new  > gophermap.new
+
+[ $? -eq 0 ] && {
+	mv config.txt.new config.txt
+	mv gophermap.new gophermap
+} 
+
+```

phrollo

@@ -3,25 +3,12 @@
 # MIT License
 
 FILEIN="${1:-/dev/stdin}"
-TODAY="$(date +%Y%m%d)"
-if [ "${FILEIN}" != '/dev/stdin' ]; then { 
-	cat "${FILEIN}" | tee "${FILEIN}".bak > "${FILEIN}".new
-	FILEOUT="${FILEIN}".new
-} else {
-	FILEOUT="$(basename $0).out"
-}
-fi
-
 IFS='	'
 while read -r D T S H P SH; do
 	NSH="$(printf "$S\r\n"  | nc $H $P | shasum -a 256 | cut -d " " -f 1)"
 	[ $? -eq 0 ] && 
-	[ "${SH}" !=  "${NSH}" ] && {
+	[ "${SH}" !=  "${NSH}" ] && {D="$(date +%Y%m%d)"; SH="${NSH}"}
-		D="${TODAY}"
+	printf "%s\t%s\t%s\t%s\t%s\t%s\n" "$D" "$T" "$S" "$H" "$P" "$SH" | tee /dev/stderr 
-		SH="${NSH}"
+done < "${FILEIN}" | sort -rnk1 -k2 | \
-	}
-	printf "%s\t%s\t%s\t%s\t%s\t%s\n" "$D" "$T" "$S" "$H" "$P" "$SH"
-done < "${FILEIN}" | sort -rnk1 -k2 | tee "${FILEOUT}" | \
 	sed -r "s/^([0-9][0-9]*)	/1(\1) /g;s/	[a-f0-9][a-f0-9]*$//g" |\
 	sort -rk1 -k2 
-