From 19caadc8c931825bd1d1547ae6835e6820fc7b5f Mon Sep 17 00:00:00 2001
From: Michael Marineau <michael.marineau@coreos.com>
Date: Tue, 6 Aug 2013 13:50:17 -0400
Subject: [PATCH] feat(common): Add simple version comparison function.

Relies on sort for version comparison which should generally be good
enough. Not a proper semver tool but good enough for dirty scripts. :)
---
 common.sh | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/common.sh b/common.sh
index e49316943d..fb0d2f753c 100644
--- a/common.sh
+++ b/common.sh
@@ -159,6 +159,19 @@ die_notrace() {
   exit 1
 }
 
+# Simple version comparison routine
+# Note: not a true semver comparison and build revisions are ignored
+cmp_ver() {
+  local rev a="${2%%+*}" b="${3%%+*}"
+  case "$1" in
+    le) rev="" ;;
+    ge) rev="-R" ;;
+    *) die "Invalid operator $1" ;;
+  esac
+  printf '%s\n%s\n' "$a" "$b" | sort --version-sort --check=quiet $rev
+  return $?
+}
+
 # Directory locations inside the dev chroot; try the new default,
 # falling back to user specific paths if the upgrade has yet to
 # happen.