adb version tested
$ adb --version
Android Debug Bridge version 1.0.41
Version 31.0.2-7242960
Print all options
$ adb logcat -h
Usage: logcat [options] [filterspecs]
General options:
-b, --buffer=<buffer> Request alternate ring buffer(s):
main system radio events crash default all
Additionally, 'kernel' for userdebug and eng builds, and
......
Check logcat buffer size
-g, --buffer-size Get the size of the ring buffers within logd.
$ adb logcat -g
main: ring buffer is 5 MiB (4 MiB consumed), max entry is 5120 B, max payload is 4068 B
system: ring buffer is 2 MiB (1 MiB consumed), max entry is 5120 B, max payload is 4068 B
crash: ring buffer is 256 KiB (0 B consumed), max entry is 5120 B, max payload is 4068 B
kernel: ring buffer is 256 KiB (0 B consumed), max entry is 5120 B, max payload is 4068 B
Change logcat buffer size
-b, --buffer=<buffer> Request alternate ring buffer(s):
main system radio events crash default all
Additionally, 'kernel' for userdebug and eng builds, and
'security' for Device Owner installations.
Multiple -b parameters or comma separated list of buffers are
allowed. Buffers are interleaved.
Default -b main,system,crash,kernel.
-G, --buffer-size=<size> Set size of a ring buffer in logd. May suffix with K or M.
This can individually control each buffer's size with -b.
set system buffer
$ adb logcat -G 5M -b system
$ adb logcat -g
main: ring buffer is 5 MiB (4 MiB consumed), max entry is 5120 B, max payload is 4068 B
system: ring buffer is 5 MiB (1 MiB consumed), max entry is 5120 B, max payload is 4068 B
crash: ring buffer is 256 KiB (0 B consumed), max entry is 5120 B, max payload is 4068 B
kernel: ring buffer is 256 KiB (0 B consumed), max entry is 5120 B, max payload is 4068 B
set all buffer
$ adb logcat -G 5M
$ adb logcat -g
main: ring buffer is 5 MiB (4 MiB consumed), max entry is 5120 B, max payload is 4068 B
system: ring buffer is 5 MiB (1 MiB consumed), max entry is 5120 B, max payload is 4068 B
crash: ring buffer is 5 MiB (0 B consumed), max entry is 5120 B, max payload is 4068 B
kernel: ring buffer is 5 MiB (0 B consumed), max entry is 5120 B, max payload is 4068 B
Clear all logs
-c, --clear Clear (flush) the entire log and exit.
if -f is specified, clear the specified file and its related rotated
log files instead.
if -L is specified, clear pstore log instead.
$ adb logcat -c
Dump logs(non block)
-d Dump the log and then exit (don't block).
$ adb logcat -d
--------- beginning of system
12-30 15:11:05.979 1132 5037 I ActivityManager: Process com.samsung.android.dqagent
--------- beginning of main
12-30 15:11:05.980 825 825 I Zygote : Process 25662 exited due to signal 9 (Killed)
12-30 15:11:05.980 604 604 I lmkd : cached 5, sandbox(not0) 2
12-30 15:11:05.981 1132 1423 I libprocessgroup: Successfully killed process cgroup
......
12-30 15:11:14.978 805 805 E audit : type=1327 audit(1640844674.973:574366029):
12-30 15:11:14.978 805 805 E audit : type=1400 audit(1640844674.977:574366030):
12-30 15:11:14.978 805 805 E audit : type=1300 audit(1640844674.977:574366030):
$
Save logs(block)
Option (adb logcat -h)
Outfile files:
-f, --file=<file> Log to file instead of stdout.
-r, --rotate-kbytes=<n> Rotate log every <n> kbytes. Requires -f option.
-n, --rotate-count=<count> Sets max number of rotated logs to <count>, default 4.
1000K, Max 20, save to /storage/emulated/0/logcat
$ adb logcat -r 1000 -n 20 -f /storage/emulated/0/logcat/logcat.log
$ adb shell ls -lh /storage/emulated/0/logcat/
total 676K
-rw-rw---- 1 root everybody 634K 2021-12-30 15:24 logcat.log
-rw-rw---- 1 root everybody 0.9M 2021-12-30 15:24 logcat.log.01
$ adb shell ls -lh /storage/emulated/0/logcat/
total 1.0M
-rw-rw---- 1 root everybody 222K 2021-12-30 15:25 logcat.log
-rw-rw---- 1 root everybody 0.9M 2021-12-30 15:24 logcat.log.01
-rw-rw---- 1 root everybody 0.9M 2021-12-30 15:24 logcat.log.02
Filtering
Filtering:
-s Set default filter to silent. Equivalent to filterspec '*:S'
......
filterspecs are a series of
<tag>[:priority]
where <tag> is a log component tag (or * for all) and priority is:
V Verbose (default for <tag>)
D Debug (default for '*')
I Info
W Warn
E Error
F Fatal
S Silent (suppress all output)
$ adb logcat -s "AlarmManager:*" "BatteryStatsService:*"
12-30 15:39:24.326 1132 1836 E AlarmManager: Set nextNonWakeup as mNextNonWakeupDelive
12-30 15:39:24.353 1132 4035 I BatteryStatsService: In wakeup_callback: resumed from
12-30 15:39:25.054 1132 4935 I BatteryStatsService: In wakeup_callback: suspend aborted
12-30 15:39:26.410 1132 3545 V AlarmManager: unblockMARsRestrictedAlarmsForUidPackage
Print with thread, time
-v <format>, --format=<format> options:
Sets log print format verb and adverbs, where <format> is:
brief long process raw tag thread threadtime time
default : Depends on the adb version
$ adb logcat -s "AlarmManager:*"
12-30 15:26:40.860 1132 1836 E AlarmManager: Set nextNonWakeup as mNextNonWakeupDelive
$ adb logcat -s "AlarmManager:*" -v time
12-30 15:22:01.749 E/AlarmManager( 1132): Set nextNonWakeup as mNextNonWakeupDeliveryTime
$ adb logcat -s "AlarmManager:*" -v thread
E( 1132: 1836) Set nextNonWakeup as mNextNonWakeupDeliveryTime=781912438 , orig nextNonWakeup=0
$ adb logcat -s "AlarmManager:*" -v threadtime
12-30 15:14:24.021 1132 1836 E AlarmManager: Set nextNonWakeup as mNextNonWakeupDelive
Apply color by log level
$ adb logcat -v color
