contrib/verifybinaries: allow filtering by platform

Downloading all the binaries of all platforms can take quite long,
especially for slow connections, which may deter people from using
this script and, therefore, to disregard security altogether.

This change introduces the new possibility of specifying the
platform along with the version number, so that only the binaries
that contain the platform name are downloaded.

contrib/verifybinaries/README.md

@@ -26,6 +26,14 @@ The script returns 0 if everything passes the checks. It returns 1 if either the
 ./verify.sh bitcoin-core-0.13.0-rc3
 ```
 
+If you only want to download the binaries of certain platform, add the corresponding suffix, e.g.:
+
+```sh
+./verify.sh bitcoin-core-0.11.2-osx
+./verify.sh 0.12.0-linux
+./verify.sh bitcoin-core-0.13.0-rc3-win64
+```
+
 If you do not want to keep the downloaded binaries, specify anything as the second parameter.
 
 ```sh

contrib/verifybinaries/verify.sh

@@ -42,13 +42,36 @@ if [ -n "$1" ]; then
       VERSION="$VERSIONPREFIX$1"
    fi
 
-   #now let's see if the version string contains "rc", and strip it off if it does
+   STRIPPEDLAST="${VERSION%-*}"
-   #  and simultaneously add RCSUBDIR to BASEDIR, where we will look for SIGNATUREFILENAME
+
-   if [[ $VERSION == *"$RCVERSIONSTRING"* ]]; then
+   #now let's see if the version string contains "rc" or a platform name (e.g. "osx")
-      BASEDIR="$BASEDIR${VERSION/%-$RCVERSIONSTRING*}/"
+   if [[ "$STRIPPEDLAST-" == "$VERSIONPREFIX" ]]; then
-      BASEDIR="$BASEDIR$RCSUBDIR.$RCVERSIONSTRING${VERSION: -1}/"
+      BASEDIR="$BASEDIR$VERSION/"
+   else
+      # let's examine the last part to see if it's rc and/or platform name
+      STRIPPEDNEXTTOLAST="${STRIPPEDLAST%-*}"
+      if [[ "$STRIPPEDNEXTTOLAST-" == "$VERSIONPREFIX" ]]; then
+
+         LASTSUFFIX="${VERSION##*-}"
+         VERSION="$STRIPPEDLAST"
+
+         if [[ $LASTSUFFIX == *"$RCVERSIONSTRING"* ]]; then
+            RCVERSION="$LASTSUFFIX"
+         else
+            PLATFORM="$LASTSUFFIX"
+         fi
+
       else
+         RCVERSION="${STRIPPEDLAST##*-}"
+         PLATFORM="${VERSION##*-}"
+
+         VERSION="$STRIPPEDNEXTTOLAST"
+      fi
+
       BASEDIR="$BASEDIR$VERSION/"
+      if [[ $RCVERSION == *"$RCVERSIONSTRING"* ]]; then
+         BASEDIR="$BASEDIR$RCSUBDIR.$RCVERSION/"
+      fi
    fi
 
    SIGNATUREFILE="$BASEDIR$SIGNATUREFILENAME"
@@ -92,12 +115,22 @@ if [ $RET -ne 0 ]; then
    exit "$RET"
 fi
 
+if [ -n "$PLATFORM" ]; then
+   grep $PLATFORM $TMPFILE > "$TMPFILE-plat"
+   TMPFILESIZE=$(stat -c%s "$TMPFILE-plat")
+   if [ $TMPFILESIZE -eq 0 ]; then
+      echo "error: no files matched the platform specified" && exit 3
+   fi
+   mv "$TMPFILE-plat" $TMPFILE
+fi
+
 #here we extract the filenames from the signature file
 FILES=$(awk '{print $2}' "$TMPFILE")
 
 #and download these one by one
 for file in $FILES
 do
+   echo "Downloading $file"
    wget --quiet -N "$BASEDIR$file"
 done