Improved ./release.sh

Some more automatization of relase:
1. Version number is guessed based on current branch
2. Date in changelog is automatically set

release.sh

@@ -17,6 +17,19 @@ confirm () {
     esac
 }
 
+update_changelog() {
+  echo $1 $2 $3
+  awk -v version="$2" -v date="$3" '{
+    if($1=="Version" && $2==version){
+      print "Version " version " (" date ")"
+      done=1
+    } else if(!done && $1=="Unreleased" && $2=="changes"){
+      print "Version " version " (" date ")"
+    } else print
+  }' $1 > $1.tmp
+  mv $1.tmp $1
+}
+
 VALIDATED=
 if [ "$1" = --validated ] ; then
   VALIDATED=yes
@@ -27,15 +40,38 @@ elif test -n "$1" ; then
 fi
 
 
-echo "*** Only use this script if you want to release a new PLUMED version ***"
-echo "*** follow instructions below ***"
+echo "*** Only use this script if you want to release a new PLUMED version. ***"
+echo "*** Follow instructions below, and use Control-C to exit. ***"
 
 ls src README 1>/dev/null 2>/dev/null ||  {
   echo "Launch from root directory"
   exit 1
 }
 
-read -r -p "Type the version number (e.g. 2.1.3 or 2.2b): " version
+# Guess version number:
+branch="$(git status | grep "On branch" | awk '{print $3}')"
+for((i=0;;i++))
+do
+  guess="${branch#v}.$i"
+  if ! git tag | grep -q "^v${guess//./\\.}$" ; then
+    echo "Guessed next version: ${guess}"
+    break;
+  fi
+done
+
+case "$branch" in
+(v2.?*)
+  read -r -p "Type the version number (default: ${guess}): " version
+  case "$version" in
+  ("")
+    version="$guess"
+  esac
+  ;;
+(*)
+  read -r -p "Type the version number (e.g. 2.1.3 or 2.2b): " version
+  ;;
+esac
+
 
 case "$version" in
 (2.?*)
@@ -67,10 +103,12 @@ if test "$(git tag -l | awk '{if($1=="'v$version'")print "yes"}')" == yes ; then
   exit 1
 fi
 
+echo "checking out branch v$shortversion"
+git checkout v$shortversion
+
 set -e
 if ! test "$VALIDATED" ; then
-  echo "checking out branch v$shortversion"
-  git checkout v$shortversion
+  update_changelog CHANGES/v$shortversion.txt $version "coming soon"
   echo 
   msg="Travis tests for v$version
 
@@ -78,10 +116,12 @@ if ! test "$VALIDATED" ; then
   echo "Now I will add an empty commit and push the result to origin"
   echo "I will use the following commands:"
   echo "***"
+  echo "git add CHANGES/v$shortversion.txt"
   echo "git commit --allow-empty -m \"$msg\""
   echo "git push origin v$shortversion"
   echo "***"
   confirm || exit
+  git add CHANGES/v$shortversion.txt
   git commit --allow-empty -m "$msg"
   git push origin v$shortversion
   echo
@@ -93,6 +133,7 @@ if ! test "$VALIDATED" ; then
   echo "  http://plumed.github.io/doc-v$shortversion"
   echo "In case of success, relaunch this script as \"./release.sh --validated\""
 else
+  update_changelog CHANGES/v$shortversion.txt $version "$(date '+%b %e, %Y' | sed 's/  / /g')"
   {
     grep  \# VERSION 
     echo $version