From 17ab178cdd30e09eb1368971b26841d24dc6e164 Mon Sep 17 00:00:00 2001
From: Alessandro Mauri <alemauri001@gmail.com>
Date: Sat, 22 Aug 2020 23:34:05 +0200
Subject: [PATCH] more improvements

- payload now extracts in the right location
- payload checks if the file is already extracted
- etc.
---
 .gitignore    |  3 +--
 posix/preload | 30 +++++++++++++++++++-----------
 posix/prepare |  2 +-
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/.gitignore b/.gitignore
index 7039b0b..d3745c1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1 @@
-**/pcmi/**
-**/badwolf/**
+tests/**
diff --git a/posix/preload b/posix/preload
index a07bd1c..6adafff 100755
--- a/posix/preload
+++ b/posix/preload
@@ -1,19 +1,27 @@
 #!/bin/sh -e
 
 # TODO: verify checksum before extracting
-# SUM
 # TODO: extract self without resolving to $0 because it doesn't resolve links
-tail -c +"$(expr BYTES + 1)" $0 | lz4 -dc | tar -x
-# TODO: remove hardcoded directory
-# TODO: use a different extraction path
-cd ID
 
-export ORIGIN="$(pwd)"
-export LD_LIBRARY_PATH="$ORIGIN/lib"
-export PATH="$ORIGIN/bin":$PATH
+if [ -z "$XDG_CACHE_HOME" ]; then
+	destdir=/tmp
+else
+	destdir="$XDG_CACHE_HOME"
+fi
 
-#export LD_DEBUG='libs'
+if ! [ "$(head -n 1 "$destdir"/ID/checksum 2>/dev/null)" = 'SUM' ]; then
+	tail -c +BYTES "$0" | lz4 -dc | tar -x -C "$destdir"
+	echo "SUM" > "$destdir"/ID/checksum
+fi
+
+ORIGIN="$destdir"/ID
+LD_LIBRARY_PATH="$ORIGIN/lib"
+PATH="$ORIGIN/bin":$PATH
+export ORIGIN
+export LD_LIBRARY_PATH
+export PATH
+
+# export LD_DEBUG='libs'
 
 # TODO: use $0 instead
-# FIXME: uses the system's basename
-exec bin/"$(basename "$1")"
+exec "$destdir"/ID/bin/"$(basename "$1")"
diff --git a/posix/prepare b/posix/prepare
index dde0a3a..f160d29 100755
--- a/posix/prepare
+++ b/posix/prepare
@@ -148,7 +148,7 @@ awk '!/^ *#/ && NF' > tpp
 size="$(wc -c tpp | cut -d " " -f1)"
 strsize="$(echo "BYTES" | wc -c)"
 numsize="$(echo "$size" | wc -c)"
-normsize="$((size - (strsize - numsize)))"
+normsize="$((size - (strsize - numsize) + 1))"
 
 sed s/BYTES/"$normsize"/ tpp > tpr
 cat tpr "$DIRNAME".tar.lz4 > "$DIRNAME".ti