[pacman-dev] [PATCH] pacdiff - implement default search using local pacman db

[John Frazier]

Use pacman local db to find pacnews based on active configs. Relegate
find to an option. Rename DIFFSEARCHPATH to DIFFFINDPATH to clarify use.
Add quit option to prompts. Clarify help.

---
 contrib/pacdiff.sh.in | 65 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 18 deletions(-)

diff --git a/contrib/pacdiff.sh.in b/contrib/pacdiff.sh.in
index 47779d6..25c3fd6 100644
--- a/contrib/pacdiff.sh.in
+++ b/contrib/pacdiff.sh.in
@@ -22,8 +22,8 @@ declare -r myname='pacdiff'
 declare -r myver='@PACKAGE_VERSION@'
 
 diffprog=${DIFFPROG:-vimdiff}
-diffsearchpath=${DIFFSEARCHPATH:-/etc}
-locate=0
+difffindpath=${DIFFFINDPATH:-/etc}
+diffpacmandb=${DIFFPACMANDB:-/var/lib/pacman}
 USE_COLOR='y'
 
 m4_include(../scripts/library/output_format.sh)
@@ -32,11 +32,21 @@ m4_include(../scripts/library/term_colors.sh)
 
 usage() {
 	echo "$myname : a simple pacnew/pacorig/pacsave updater"
-	echo "Usage : $myname [-l]"
-	echo "  -l/--locate makes $myname use locate rather than find"
-	echo "  DIFFPROG variable allows to override the default vimdiff"
-	echo "  DIFFSEARCHPATH allows to override the default /etc path"
-	echo "Example : DIFFPROG=meld DIFFSEARCHPATH=\"/boot /etc /usr\" $myname"
+	echo ""
+	echo "Usage : $myname [-lf]"
+	echo "  -l/--locate makes $myname search using locate"
+	echo "  -f/--find   makes $myname search using find"
+	echo ""
+	echo "Note: the default search looks for backup files in the local pacman db"
+	echo "      this generally will not find *.pacsave files"
+	echo ""
+	echo "  DIFFPROG variable will override the default editor: vimdiff"
+	echo "  DIFFFINDPATH will override the default path when using --find"
+	echo "  DIFFPACMANDB will override the default pacman db for the "
+	echo "    default search type"
+	echo ""
+	echo "Example : DDIFFPROG=meld DIFFPACMANDB=/mnt/var/lib/pacman/ $myname"
+	echo "Example : DIFFFINDPATH=\"/boot /etc /usr\" $myname"
 }
 
 version() {
@@ -45,18 +55,12 @@ version() {
 	echo 'Copyright (C) 2013 Pacman Development Team <pacman-dev at archlinux.org>'
 }
 
-cmd() {
-	if [ $locate -eq 1 ]; then
-		locate -0 -e -b \*.pacnew \*.pacorig \*.pacsave
-	else
-		find $diffsearchpath \( -name \*.pacnew -o -name \*.pacorig -o -name \*.pacsave \) -print0
-	fi
-}
-
 if [ $# -gt 0 ]; then
 	case $1 in
 		-l|--locate)
-		locate=1;;
+			locate=$(type -P locate);;
+		-f|--find)
+			find=$(type -P find);;
 		-V|--version)
 		version; exit 0;;
 		-h|--help)
@@ -66,6 +70,30 @@ if [ $# -gt 0 ]; then
 	esac
 fi
 
+check_backup() {
+  [[ -f $1 ]] && printf "$1"'\0'
+}
+
+cmd() {
+	if [[ -n $locate ]]; then
+		locate -0 -e -b \*.pacnew \*.pacorig \*.pacsave
+	elif [[ -n $find ]]; then
+		find "${difffindpath}" \( -name \*.pacnew -o -name \*.pacorig -o -name \*.pacsave \) -print0 2> /dev/null
+	else
+		# parse local pacman db for backup files and look for pac* based on them
+		awk '/^%BACKUP%$/ {
+			while (getline) {
+				if (/^$/) { nextfile }
+				print $1
+			}
+		}' "${diffpacmandb}"/local/*/files | while read -r bkup; do
+			check_backup "/$bkup.pacnew"
+			check_backup "/$bkup.pacorig"
+			check_backup "/$bkup.pacsave"
+		done
+	fi
+}
+
 # see http://mywiki.wooledge.org/BashFAQ/020
 while IFS= read -u 3 -r -d '' pacfile; do
 	file="${pacfile%.pac*}"
@@ -82,16 +110,17 @@ while IFS= read -u 3 -r -d '' pacfile; do
 		msg2 "Files are identical, removing..."
 		rm -v "$pacfile"
 	else
-		ask "(V)iew, (S)kip, (R)emove %s, (O)verwrite with %s: [v/s/r/o] " "$file_type" "$file_type"
+		ask "(V)iew, (S)kip, (R)emove %s, (O)verwrite with %s, (Q)uit: [v/s/r/o/q] " "$file_type" "$file_type"
 		while read c; do
 			case $c in
+				q|Q) exit 1;;
 				r|R) rm -v "$pacfile"; break ;;
 				o|O) mv -v "$pacfile" "$file"; break ;;
 				v|V)
 				$diffprog "$pacfile" "$file"
 				rm -iv "$pacfile"; break ;;
 				s|S) break ;;
-				*) ask "Invalid answer. Try again: [v/s/r/o] "; continue ;;
+				*) ask "Invalid answer. Try again: [v/s/r/o/q] "; continue ;;
 			esac
 		done
 	fi
-- 
1.8.3