add: dmesg logging; improve: make logs based on extracted suffix for dmesg pairing with logcats on action.sh

This commit uses grep -oE to extract the log suffix "-2" (action.sh) or "2" (post-fs-data.sh)
it allows the new dmesg logs to be paired with the corresponding log on the action script
and also allow a simplification on post-fs-data.sh by checking if the last log is not the last before returning to the starting log (3) and if the initial log is existent to add 1 to the last log which defaults to 2 (1+1) if it doesn't contain a suffix (first log)
while if the starting log is non existent or the last log was the finishing one before looping back (3) it will use no suffix to create the starting log

Signed-off-by: TheSillyOk <priv.ld@proton.me>

Author: TheSillyOk

post-fs-data.sh

@@ -3,30 +3,47 @@
 # A tool to collect extremely verbose debug log from the Android system.
 # LICENSE: BSD 3-Clause by ThePedroo
 
-SAVE_FOLDER=/data/local/tmp/DebugAssistant
-
+SAVE_FOLDER="/data/local/tmp/DebugAssistant"
 mkdir -p "$SAVE_FOLDER"
 
-function prepare_file() {
+start_log() {
+  local suffix="$1"
+
+  watch_logcat "$suffix"
+  watch_dmesg "$suffix"
+}
+
+prepare_file() {
   local file_path="$1"
 
   rm "$file_path"
   touch "$file_path"
   chown shell:shell "$file_path"
 }
 
-function watch_logcat() {
+watch_logcat() {
   local file_path="$SAVE_FOLDER/DebugAssistant$1.log"
   prepare_file "$file_path"
 
   while [ ! ];do logcat;sleep 1;done > "$file_path" &
 }
 
+watch_dmesg() {
+  local file_path="$SAVE_FOLDER/DebugAssistant-DMESG$1.log"
+  prepare_file "$file_path"
+
+  if dmesg --help 2>&1 | grep -q "\-w"; then
+    dmesg -w > "$file_path" &
+  else
+    while [ ! ];do dmesg > "$file_path";sleep 1;done &
+  fi
+}
+
 LATEST_SUFFIX=$(basename $(ls -t "$SAVE_FOLDER"/DebugAssistant*.log | grep -v "Redacted" | head -n 1) | grep -oE "([0-9]+)?")
 if [[ -z "$(ls $SAVE_FOLDER/DebugAssistant*.log)" || "${LATEST_SUFFIX:-1}" -ge 3 ]]; then
   SUFFIX=""
 else
   SUFFIX="-$(( ${LATEST_SUFFIX:-1} + 1 ))"
 fi
 
-watch_logcat "$SUFFIX"
+start_log "$SUFFIX"