Append run output to a log and list leftover .new configs

Non-interactive runs leave obsolete .new config files in place: new-config
exits without acting and there was no record to debug later. Tee the whole
run (script messages plus slackpkg output) to LOG, default
/var/log/dist-upgrade.log, with a timestamped header per run (a second one
on a 50-restart). LOG= disables it.

Also report leftover .new files under /etc and /boot at the end of a run.

2 files changed, 40 insertions, 1 deletions

diff --git a/README.md b/README.md
index 941808c..63e35b3 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,8 @@ Options:
 Environment:
 
 - `INITRD` initrd to inspect (default `/boot/initrd-generic.img`)
+- `LOG` append the whole run, slackpkg output included, to this file
+  (default `/var/log/dist-upgrade.log`; set it empty to disable)
 
 ## What it does
 
@@ -33,7 +35,11 @@ Environment:
    - the modules `mkinitrd_command_generator.sh` says are needed against the
      initrd's contents,
    - the module set against the pre-upgrade snapshot (notices modules lost).
-4. Reports whether a reboot is recommended.
+4. Lists any leftover `.new` config files.
+5. Reports whether a reboot is recommended.
+
+The full run is appended to `LOG`, with a timestamped header per run, so an
+unattended upgrade can be reviewed afterwards.
 
 If slackpkg upgrades itself mid-run (exit status 50) the script re-executes
 once from the top to finish the operation, exactly as slackpkg's own message
diff --git a/dist-upgrade b/dist-upgrade
index 39b40a8..57594ed 100755
--- a/dist-upgrade
+++ b/dist-upgrade
@@ -19,6 +19,7 @@ export LC_ALL=C
 
 INITRD=${INITRD:-/boot/initrd-generic.img}
 MKINITRD_GEN=/usr/share/mkinitrd/mkinitrd_command_generator.sh
+LOG=${LOG-/var/log/dist-upgrade.log}
 
 INTERACTIVE=0
 TMPDIR_SNAP=""
@@ -44,6 +45,8 @@ to boot.
 
 Environment:
   INITRD              initrd to inspect (default /boot/initrd-generic.img)
+  LOG                 append run output here (default /var/log/dist-upgrade.log;
+                      set empty to disable)
 EOF
 }
 
@@ -136,6 +139,32 @@ run_step() {
   handle_rc "$cmd" $?
 }
 
+setup_log() {
+  [ -n "$LOG" ] || return 0
+  if ! : >> "$LOG" 2>/dev/null; then
+    warn "cannot write log $LOG, continuing without logging"
+    LOG=""
+    return 0
+  fi
+  local mode=non-interactive
+  [ "$INTERACTIVE" -eq 1 ] && mode=interactive
+  {
+    printf '\n===== dist-upgrade %s =====\n' "$(date '+%Y-%m-%d %H:%M:%S')"
+    printf 'mode: %s\n' "$mode"
+    printf 'args:%s\n' "$(printf ' %s' "${ORIG_ARGS[@]}")"
+  } >> "$LOG"
+  exec > >(tee -a "$LOG") 2>&1
+}
+
+# ponytail: only /etc and /boot are scanned for .new files; other paths are not
+report_leftovers() {
+  local found
+  found=$(find /etc /boot -name '*.new' 2>/dev/null | sort)
+  [ -n "$found" ] || return 0
+  info "Leftover .new config files (review, then adopt or delete):"
+  printf '%s\n' "$found"
+}
+
 snapshot_initrd() {
   if [ ! -e "$INITRD" ] && [ ! -L "$INITRD" ]; then
     info "snapshot: no initrd at $INITRD, skipping initrd checks."
@@ -265,6 +294,8 @@ done
 
 [ "$(id -u)" -eq 0 ] || die "must be run as root"
 
+setup_log
+
 TMPDIR_SNAP=$(mktemp -d) || die "mktemp failed"
 trap 'rm -rf "$TMPDIR_SNAP"' EXIT
 
@@ -284,6 +315,8 @@ run_step new-config
 
 check_initrd
 
+report_leftovers
+
 running=$(uname -r)
 newver=$(newest_kernel)
 if [ -n "$newver" ] && [ "$running" != "$newver" ]; then