From 6ad16c2b74db3e10ce6deb08aab358e931bc64bf Mon Sep 17 00:00:00 2001
From: Fulvio Valente <fulvio.valente@ncr.com>
Date: Thu, 16 Nov 2017 15:11:19 +0000
Subject: [PATCH] Use expr instead of bc when checking Java versions.

Because expr is in coreutils, we can expect it to be present on systems unlike bc.

Fixes #198
Fixes #192
---
 build.sbt                             | 2 +-
 src/universal/bin/sbt-launch-lib.bash | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/build.sbt b/build.sbt
index a077de6d0..a0e109a4a 100644
--- a/build.sbt
+++ b/build.sbt
@@ -91,7 +91,7 @@ val root = (project in file(".")).
     },
     // Used to have "openjdk-8-jdk" but that doesn't work on Ubuntu 14.04 https://github.com/sbt/sbt/issues/3105
     // before that we had java6-runtime-headless" and that was pulling in JDK9 on Ubuntu 16.04 https://github.com/sbt/sbt/issues/2931
-    debianPackageDependencies in Debian ++= Seq("bash (>= 3.2)", "bc"),
+    debianPackageDependencies in Debian ++= Seq("bash (>= 3.2)"),
     debianPackageRecommends in Debian += "git",
     linuxPackageMappings in Debian += {
       val bd = sourceDirectory.value
diff --git a/src/universal/bin/sbt-launch-lib.bash b/src/universal/bin/sbt-launch-lib.bash
index 5071bd2aa..7504df246 100755
--- a/src/universal/bin/sbt-launch-lib.bash
+++ b/src/universal/bin/sbt-launch-lib.bash
@@ -118,7 +118,7 @@ get_mem_opts () {
 }
 
 get_gc_opts () {
-  local older_than_9="$(echo "$java_version < 9" | bc)"
+  local older_than_9="$(expr $java_version "<" 9)"
 
   if [[ "$older_than_9" == "1" ]]; then
     # don't need to worry about gc
@@ -204,7 +204,7 @@ syncPreloaded() {
 checkJava() {
   local required_version="$1"
   # Now check to see if it's a good enough version
-  local good_enough="$(echo "$java_version >= $required_version" | bc)"
+  local good_enough="$(expr $java_version ">=" $required_version)"
   if [[ "$java_version" == "" ]]; then
     echo
     echo "No Java Development Kit (JDK) installation was detected."
@@ -225,7 +225,7 @@ checkJava() {
 }
 
 copyRt() {
-  local at_least_9="$(echo "$java_version >= 9" | bc)"
+  local at_least_9="$(expr $java_version ">=" 9)"
   if [[ "$at_least_9" == "1" ]]; then
     rtexport=$(rt_export_file)
     java9_ext=$("$java_cmd" ${JAVA_OPTS} ${SBT_OPTS:-$default_sbt_opts} ${java_args[@]} \