From: Mike Frysinger <vapier@gentoo.org>
Date: Mon, 24 Sep 2012 00:16:54 +0000 (-0400)
Subject: use `readlink -f` if it works
X-Git-Tag: v2.2.0_alpha133~32
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=ca46b021359ffa13a808f99dd635a6958b369be5;p=portage.git

use `readlink -f` if it works

Rather than always re-implementing `readlink -f` in shell, probe the host
tool first to see if it works.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---

diff --git a/bin/misc-functions.sh b/bin/misc-functions.sh
index ac08bd948..c8b7cc8b0 100755
--- a/bin/misc-functions.sh
+++ b/bin/misc-functions.sh
@@ -43,7 +43,20 @@ install_symlink_html_docs() {
 }
 
 # replacement for "readlink -f" or "realpath"
+READLINK_F_WORKS=""
 canonicalize() {
+	if [[ -z ${READLINK_F_WORKS} ]] ; then
+		if [[ $(readlink -f -- /../ 2>/dev/null) == "/" ]] ; then
+			READLINK_F_WORKS=true
+		else
+			READLINK_F_WORKS=false
+		fi
+	fi
+	if ${READLINK_F_WORKS} ; then
+		readlink -f -- "$@"
+		return
+	fi
+
 	local f=$1 b n=10 wd=$(pwd)
 	while (( n-- > 0 )); do
 		while [[ ${f: -1} = / && ${#f} -gt 1 ]]; do