From 8383a03f122bc866f8b77e4b312778c97cd77622 Mon Sep 17 00:00:00 2001
From: Erich Eckner <git@eckner.net>
Date: Fri, 21 Jun 2019 11:01:27 +0200
Subject: bin/bisect-database-dumps new to bisect through the database dumps

---
 bin/bisect-database-dumps | 60 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100755 bin/bisect-database-dumps

diff --git a/bin/bisect-database-dumps b/bin/bisect-database-dumps
new file mode 100755
index 0000000..c943107
--- /dev/null
+++ b/bin/bisect-database-dumps
@@ -0,0 +1,60 @@
+#!/bin/sh
+
+dumps=$(
+  find '/data/backup' -mindepth 1 -maxdepth 1 -name 'database-*.xz' -exec ls -tr {} +
+)
+
+has=$(
+  printf '%s\n' "$dumps" | \
+    tail -n1
+)
+
+if ! xzgrep -q "$@" "${has}"; then
+  >&2 printf 'cannot find "%s" in the latest dump\n' "$*"
+fi
+
+has_not=$(
+  printf '%s\n' "$dumps" | \
+    head -n1
+)
+
+if xzgrep -q "$@" "${has_not}"; then
+  >&2 printf 'first dump does also have "%s"\n' "$*"
+fi
+
+count=$(
+  printf '%s\n' "${dumps}" | \
+    wc -l
+)
+
+>&2 printf '%s dumps to check\n' "${count}"
+
+while [ "${count}" -gt 2 ]; do
+  pivot=$(
+    printf '%s\n' "${dumps}" | \
+      sed -n '
+        \@^'"${has_not}"'$@,\@^'"${has}"'$@p
+      ' | \
+      sed -n '
+        '"$((count/2+1))"' p
+      '
+  )
+  >&2 printf 'looking into "%s" ... ' "${pivot}"
+  if xzgrep -q "$@" "${pivot}"; then
+    >&2 printf 'has'
+    has="${pivot}"
+  else
+    >&2 printf 'has not'
+    has_not="${pivot}"
+  fi
+  count=$(
+    printf '%s\n' "${dumps}" | \
+      sed -n '
+        \@^'"${has_not}"'$@,\@^'"${has}"'$@p
+      ' | \
+      wc -l
+  )
+  >&2 printf ' (%s dumps remaining)\n' "${count}"
+done
+
+printf '%s has not\n%s has\n' "${has_not}" "${has}"
-- 
cgit v1.2.3-54-g00ecf