From 81bb14e181c556e599e20ca6fdc86fdb690b8995 Mon Sep 17 00:00:00 2001
From: James FitzGibbon <james.fitzgibbon@nsn.com>
Date: Fri, 10 May 2013 14:20:16 -0700
Subject: [PATCH] bail out early if readlink is not available

readlink comes from GNU coreutils.  On systems without it, rbenv used to
spin out of control when it didn't have readlink or greadlink available
because it would re-exec the frontend script over and over instead of the
worker script in libexec.

Fixes #389
---
 libexec/rbenv       | 8 +++++++-
 libexec/rbenv-hooks | 8 +++++++-
 libexec/rbenv-init  | 8 +++++++-
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/libexec/rbenv b/libexec/rbenv
index 0e70361d..2d475857 100755
--- a/libexec/rbenv
+++ b/libexec/rbenv
@@ -12,8 +12,14 @@ if [ -n "$RBENV_DEBUG" ]; then
   set -x
 fi
 
+READLINK=$(type -p greadlink readlink | head -1)
+if [ -z "$READLINK" ]; then
+  echo "rbenv: cannot find readlink - are you missing GNU coreutils?" >&2
+  exit 1
+fi
+
 resolve_link() {
-  $(type -p greadlink readlink | head -1) "$1"
+  $READLINK "$1"
 }
 
 abs_dirname() {
diff --git a/libexec/rbenv-hooks b/libexec/rbenv-hooks
index f81e9af4..86386719 100755
--- a/libexec/rbenv-hooks
+++ b/libexec/rbenv-hooks
@@ -19,8 +19,14 @@ if [ -z "$RBENV_COMMAND" ]; then
   exit 1
 fi
 
+READLINK=$(type -p greadlink readlink | head -1)
+if [ -z "$READLINK" ]; then
+  echo "rbenv: cannot find readlink - are you missing GNU coreutils?" >&2
+  exit 1
+fi
+
 resolve_link() {
-  $(type -p greadlink readlink | head -1) $1
+  $READLINK "$1"
 }
 
 realpath() {
diff --git a/libexec/rbenv-init b/libexec/rbenv-init
index 8cbe7df0..7fb7b737 100755
--- a/libexec/rbenv-init
+++ b/libexec/rbenv-init
@@ -25,8 +25,14 @@ if [ -z "$shell" ]; then
   shell="$(basename "$SHELL")"
 fi
 
+READLINK=$(type -p greadlink readlink | head -1)
+if [ -z "$READLINK" ]; then
+  echo "rbenv: cannot find readlink - are you missing GNU coreutils?" >&2
+  exit 1
+fi
+
 resolve_link() {
-  $(type -p greadlink readlink | head -1) $1
+  $READLINK "$1"
 }
 
 abs_dirname() {