Make versions.sh script work on macOS too

Author: tizoc

versions.sh

@@ -9,24 +9,26 @@ fi
 VERSION=$1
 version_prefix="version = "
 
-echo "Settting version to: '$VERSION'"
+echo "Setting version to: '$VERSION'"
 for file in "${FILES[@]}"
 do
   # This version is handled manually
   if [ "$file" = "./mina-p2p-messages/Cargo.toml" ]; then
     continue
   fi
-  old_version=`cat $file | grep ^"$version_prefix"`
+  old_version=$(grep -m 1 ^"$version_prefix" "$file")
   if [ -z "$old_version" ]; then
     continue
   fi
 
   new_version="version = \"$VERSION\""
 
+  sed -i '' "s/^$old_version/$new_version/g" "$file"
+
+  version_after=$(grep ^version "$file" | tr -d "$version_prefix")
+
   version_before="${old_version/#$version_prefix}"
-  # replace version
-  sed -i "s/^$old_version/$new_version/g" $file
-  version_after=`cat $file | grep ^version |  tr --delete "$version_prefix"`
+  version_before="${version_before//\"}"
 
   echo "$file $version_before -> $version_after"
 done