From 8fdd508949e754e8ea758e8c1b3c063e41cce3f2 Mon Sep 17 00:00:00 2001
From: Lucy Phipps <landfillbaby@users.noreply.github.com>
Date: Sun, 22 Nov 2020 06:23:05 +0000
Subject: [PATCH] only bother with leaf nodes, smaller but slower? (#12)

also error message when package not found
also correctly prepend $PREFIX on reverse mode
---
 update-whatprovides-db.sh | 10 ++++++++--
 whatprovides              | 15 ++++++++++++---
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/update-whatprovides-db.sh b/update-whatprovides-db.sh
index f52a0b4..115a9f7 100755
--- a/update-whatprovides-db.sh
+++ b/update-whatprovides-db.sh
@@ -9,9 +9,15 @@ set -e -u
 : "${TERMUX_PREFIX:="/data/data/com.termux/files/usr"}"
 
 list_files() {
-	dpkg-deb --fsys-tarfile "${1}" | tar -t | cut -b2- \
+	FILES=$(dpkg-deb --fsys-tarfile "${1}" | tar -t | cut -b2- \
 		| xargs -rd\\n realpath -sm --relative-base="$TERMUX_PREFIX" -- \
-		| grep -vEx '[./]|/data(/data(/com\.termux(/files)?)?)?'
+		| grep -vEx '[./]|/data(/data(/com\.termux(/files)?)?)?')
+	SORTKEYS='-k1,1'
+	for ((x=2; x<=$(wc -L <<< "${FILES//[^\/$'\n']/}")+1; x++)); do
+		SORTKEYS="$SORTKEYS -k$x,$x"
+	done
+	sort -t/ $SORTKEYS <<< "$FILES" \
+		| awk 'NR == 1 { p=$0; next } substr($0, 1, length(p) +1 ) != p"/" { print p } { p=$0 } END { print p }'
 }
 
 write_sql_script() {
diff --git a/whatprovides b/whatprovides
index 6ce116b..acacd48 100755
--- a/whatprovides
+++ b/whatprovides
@@ -116,9 +116,17 @@ if ${REVERSE_MODE}; then
 		exit 1
 	fi
 
-	sqlite3 "${DB_PATH}" \
+	if ! sqlite3 "${DB_PATH}" \
 		"SELECT owned_file FROM 'whatprovides' WHERE package_name == '${1}' ORDER BY owned_file" \
-		| awk "NR == 1 { print \"${1}: /.\\n${1}: /data\\n${1}: /data/data\\n${1}: /data/data/com.termux\\n${1}: /data/data/com.termux/files\\n${1}: ${PREFIX}\" } { print \"${1}: ${PREFIX}/\"\$0 }"
+		| awk "{ if (substr(\$0, 1, 1) == \"/\") print \"${1}: \"\$0; else print \"${1}: ${PREFIX}/\"\$0 } END { if (NR == 0) exit 1 }"
+	then
+		{
+			echo
+			echo "Error: package '$1' is not found."
+			echo
+		} >&2
+		exit 1
+	fi
 else
 	NEWPREFIX=
 	FILE="$(realpath -sm "$1")"
@@ -141,8 +149,9 @@ else
 		NEWPREFIX="${PREFIX}/"
 	fi # else FILE is entirely separate from PREFIX (unlikely to be in DB)
 
+	FILE_ESC="${FILE//\'/\'\'}"
 	if ! sqlite3 "${DB_PATH}" \
-		"SELECT package_name FROM 'whatprovides' WHERE owned_file == '${FILE//\'/\'\'}' ORDER BY package_name" \
+		"SELECT DISTINCT package_name FROM 'whatprovides' WHERE owned_file == '${FILE_ESC}' OR substr(owned_file, 1, ${#FILE} +1) == '${FILE_ESC}/' ORDER BY package_name" \
 		| awk "{ print \$0\": ${NEWPREFIX}${FILE}\" } END { if (NR == 0) exit 1 }"
 	then
 		{