From e7844991a0ba555cc0062614dae09c65212f59a1 Mon Sep 17 00:00:00 2001
From: James Barnett <jbarnet4@tulane.edu>
Date: Tue, 26 Apr 2016 14:35:02 -0500
Subject: [PATCH] use subshell; use /tmp for file

---
 snap-pac | 48 +++++++++++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/snap-pac b/snap-pac
index 12de205..8484392 100755
--- a/snap-pac
+++ b/snap-pac
@@ -27,19 +27,26 @@ if [[ $EUID -ne 0 ]]; then
     exit 1
 fi
 
-if [[ "$1" != "pre" ]] && [[ "$1" != "post" ]]; then
+if [[ $# -ne 1 ]]; then
+    echo "ERROR: Only one argument should be passed to this script."
+    exit 1
+fi
+
+if [[ $1 != "pre" ]] && [[ $1 != "post" ]]; then
     echo "ERROR: First argument should either be 'pre' or 'post'."
     exit 1
 fi
 
 declare -r pre_or_post=$1
-declare -r prefile_prefix="/usr/share/libalpm/hooks.bin/snap-pac/.pre"
+declare -r prefile_prefix="/tmp/snap-pac-pre"
 declare -r pacman_cmd="$(sed 's./usr/bin/pacman.pacman.g' <(ps -C pacman -o args=))"
 declare -r snapper_config_dir="/etc/snapper/configs"
-declare -r configurations="$(find $snapper_config_dir/* -printf '%f\t')"
+declare -r configurations="$(find $snapper_config_dir/* -printf '%f\t\0')"
 
 for x in $configurations; do
 
+    (
+
     source $snapper_config_dir/$x
 
     if [[ $x == "root" ]]; then
@@ -48,33 +55,36 @@ for x in $configurations; do
         take_snapshot=${PACMAN_PRE_POST:-"no"}
     fi
 
-    if [[ $take_snapshot == "yes" ]]; then
+    [[ $take_snapshot != "yes" ]] && exit 0
+        
+    cleanupalgo=${PACMAN_CLEANUP_ALGORITHM:-"number"}
 
-        cleanupalgo=${PACMAN_CLEANUP_ALGORITHM:-"number"}
+    if [[ "$pre_or_post" == "pre" ]]; then
 
-        if [[ "$pre_or_post" == "pre" ]]; then
+        description=${PACMAN_PRE_DESCRIPTION:-"$pacman_cmd"}
+        snapper --config $x create --type $pre_or_post --cleanup-algorithm $cleanupalgo --print-number --description "$description" > $prefile_prefix"_"$x
+        exit 0
 
-            description=${PACMAN_PRE_DESCRIPTION:-"$pacman_cmd"}
-            snapper --config $x create --type $pre_or_post --cleanup-algorithm $cleanupalgo --print-number --description "$description" > $prefile_prefix"_"$x
+    elif [[ "$pre_or_post" == "post" ]]; then
 
-        elif [[ "$pre_or_post" == "post" ]]; then
+        if [ -f $prefile_prefix"_"$x ]; then
 
-            if [ -f $prefile_prefix"_"$x ]; then
+            description=${PACMAN_POST_DESCRIPTION:-"$pacman_cmd"}
+            snapper --config $x create --type $pre_or_post --cleanup-algorithm $cleanupalgo --pre-number $(< $prefile_prefix"_"$x) --description "$description"
+            rm $prefile_prefix"_"$x
+            exit 0
 
-                description=${PACMAN_POST_DESCRIPTION:-"$pacman_cmd"}
-                snapper --config $x create --type $pre_or_post --cleanup-algorithm $cleanupalgo --pre-number $(cat $prefile_prefix"_"$x) --description "$description"
-                rm $prefile_prefix"_"$x
+        else
 
-            else
-
-                echo "WARNING: $prefile_prefix"_"$x does not exist, so no post snapshot will be taken. If you are initially installing snap-pac, this is normal."
-
-            fi
+            echo "WARNING: $prefile_prefix"_"$x does not exist, so no post snapshot will be taken. If you are initially installing snap-pac, this is normal."
+            exit 1
 
         fi
 
     fi
 
+    ) &
+
 done
 
-exit
+exit 0