platform_system_core/logcat/logpersist

#! /system/bin/sh
# logpersist cat, start and stop handlers
progname="${0##*/}"
case `getprop ro.debuggable` in
1) ;;
*) echo "${progname} - Permission denied"
   exit 1
   ;;
esac

property=persist.logd.logpersistd

case `getprop ${property#persist.}.enable` in
true) ;;
*) echo "${progname} - Disabled"
   exit 1
   ;;
esac

log_uid=logd
log_tag_property=persist.log.tag
data=/data/misc/logd/logcat
service=logcatd
size_default=256
buffer_default=all
args="${@}"

size=${size_default}
buffer=${buffer_default}
clear=false
while [ ${#} -gt 0 ]; do
  case ${1} in
    -c|--clear) clear=true ;;
    --size=*) size="${1#--size=}" ;;
    --rotate-count=*) size="${1#--rotate-count=}" ;;
    -n|--size|--rotate-count) size="${2}" ; shift ;;
    --buffer=*) buffer="${1#--buffer=}" ;;
    -b|--buffer) buffer="${2}" ; shift ;;
    -h|--help|*)
      LEAD_SPACE_="`echo ${progname%.*} | tr '[ -~]' ' '`"
      echo "${progname%.*}.cat             - dump current ${service} logs"
      echo "${progname%.*}.start [--size=<size_in_kb>] [--buffer=<buffers>] [--clear]"
      echo "${LEAD_SPACE_}                 - start ${service} service"
      echo "${progname%.*}.stop [--clear]  - stop ${service} service"
      case ${1} in
        -h|--help) exit 0 ;;
        *) echo ERROR: bad argument ${@} >&2 ; exit 1 ;;
      esac
      ;;
  esac
  shift
done

if [ -z "${size}" -o "${size_default}" = "${size}" ]; then
  unset size
fi
if [ -n "${size}" ] &&
  ! ( [ 0 -lt "${size}" ] && [ 2048 -ge "${size}" ] ) >/dev/null 2>&1; then
  echo ERROR: Invalid --size ${size} >&2
  exit 1
fi
if [ -z "${buffer}" -o "${buffer_default}" = "${buffer}" ]; then
  unset buffer
fi
if [ -n "${buffer}" ] && ! logcat -b ${buffer} -g >/dev/null 2>&1; then
  echo ERROR: Invalid --buffer ${buffer} >&2
  exit 1
fi

log_tag="`getprop ${log_tag_property}`"
logd_logpersistd="`getprop ${property}`"

case ${progname} in
*.cat)
  if [ -n "${size}${buffer}" -o "true" = "${clear}" ]; then
    echo WARNING: Can not use --clear, --size or --buffer with ${progname%.*}.cat >&2
  fi
  su ${log_uid} ls "${data%/*}" |
  tr -d '\r' |
  sort -ru |
  sed "s#^#${data%/*}/#" |
  grep "${data}[.]*[0-9]*\$" |
  su ${log_uid} xargs cat
  ;;
*.start)
  current_buffer="`getprop ${property#persist.}.buffer`"
  current_size="`getprop ${property#persist.}.size`"
  if [ "${service}" = "`getprop ${property#persist.}`" ]; then
    if [ "true" = "${clear}" ]; then
      setprop ${property#persist.} "clear"
    elif [ "${buffer}|${size}" != "${current_buffer}|${current_size}" ]; then
      echo   "ERROR: Changing existing collection parameters from" >&2
      if [ "${buffer}" != "${current_buffer}" ]; then
        a=${current_buffer}
        b=${buffer}
        if [ -z "${a}" ]; then a="${default_buffer}"; fi
        if [ -z "${b}" ]; then b="${default_buffer}"; fi
        echo "           --buffer ${a} to ${b}" >&2
      fi
      if [ "${size}" != "${current_size}" ]; then
        a=${current_size}
        b=${size}
        if [ -z "${a}" ]; then a="${default_size}"; fi
        if [ -z "${b}" ]; then b="${default_size}"; fi
        echo "           --size ${a} to ${b}" >&2
      fi
      echo   "       Are you sure you want to do this?" >&2
      echo   "       Suggest add --clear to erase data and restart with new settings." >&2
      echo   "       To blindly override and retain data, ${progname%.*}.stop first." >&2
      exit 1
    fi
  elif [ "true" = "${clear}" ]; then
    setprop ${property#persist.} "clear"
  fi
  if [ -n "${buffer}${current_buffer}" ]; then
    setprop ${property}.buffer "${buffer}"
    if [ -z "${buffer}" ]; then
      # deal with trampoline for empty properties
      setprop ${property#persist.}.buffer ""
    fi
  fi
  if [ -n "${size}${current_size}" ]; then
    setprop ${property}.size "${size}"
    if [ -z "${size}" ]; then
      # deal with trampoline for empty properties
      setprop ${property#persist.}.size ""
    fi
  fi
  while [ "clear" = "`getprop ${property#persist.}`" ]; do
    continue
  done
  # Tell Settings that we are back on again if we turned logging off
  tag="${log_tag#Settings}"
  if [ X"${log_tag}" != X"${tag}" ]; then
    echo "WARNING: enabling logd service" >&2
    setprop ${log_tag_property} "${tag#,}"
  fi
  # ${service}.rc does the heavy lifting with the following trigger
  setprop ${property} ${service}
  # 20ms done, to permit process feedback check
  sleep 1
  getprop ${property#persist.}
  # also generate an error return code if not found running
  pgrep -u ${log_uid} ${service%d}
  ;;
*.stop)
  if [ -n "${size}${buffer}" ]; then
    echo "WARNING: Can not use --size or --buffer with ${progname%.*}.stop" >&2
  fi
  if [ "true" = "${clear}" ]; then
    setprop ${property} "clear"
  else
    setprop ${property} "stop"
  fi
  if [ -n "`getprop ${property#persist.}.buffer`" ]; then
    setprop ${property}.buffer ""
    # deal with trampoline for empty properties
    setprop ${property#persist.}.buffer ""
  fi
  if [ -n "`getprop ${property#persist.}.size`" ]; then
    setprop ${property}.size ""
    # deal with trampoline for empty properties
    setprop ${property#persist.}.size ""
  fi
  while [ "clear" = "`getprop ${property#persist.}`" ]; do
    continue
  done
  ;;
*)
  echo "ERROR: Unexpected command ${0##*/} ${args}" >&2
  exit 1
esac

if [ X"${log_tag}" != X"`getprop ${log_tag_property}`" ] ||
   [ X"${logd_logpersistd}" != X"`getprop ${property}`" ]; then
  echo "WARNING: killing Settings application to pull in new values" >&2
  am force-stop com.android.settings
fi