logcat 使用技巧--过滤器----本人备注

原文地址::http://blog.chinaunix.net/uid-25581264-id-3379198.html

1、Logcat过滤日志输出到文件----https://blog.youkuaiyun.com/jsjwangmingmin/article/details/88428794

2、adb logcat 通过包名过滤日志并输出到txt文件----https://www.cnblogs.com/slowlysnail/p/8394937.html

3、adb logcat如何过滤多个条件----https://ask.youkuaiyun.com/questions/366288

4、adb logcat命令查看并过滤android输出log----https://wenku.baidu.com/view/a7da85c3a8956bec0975e3a0.html

logcat是Android中一个命令行工具，可以用于得到程序的log信息。

logcat使用方法如下所示:
logcat [options] [filterspecs]
logcat的选项包括:
  -s                   设置过滤器，例如指定 '*:s'
  -f   输出到文件，默认情况是标准输出。
  -r [] Rotate log every kbytes. (16 if unspecified). Requires -f
  -n      Sets max number of rotated logs to , default 4
  -v      设置log的打印格式,   是下面的一种:
                     brief process tag thread raw time threadtime long

  -c                清除所有log并退出
  -d                得到所有log并退出 (不阻塞)
  -g                得到环形缓冲区的大小并退出
  -b      请求不同的环形缓冲区 ('main' (默认), 'radio', 'events')
  -B                输出log到二进制中。

过滤器的格式是一个这样的串：
  [:priority]

其中表示log的component， tag (或者使用 * 表示所有) ， priority 如下所示:
  V Verbose
  D Debug
  I Info
  W Warn
  E   Error
  F Fatal
  S Silent

****************************************************************************
过滤器使用小课堂：
I/ActivityManager( 52): Displayed activity com.android.contacts/.DialtactsContactsEntryActivity: 983 ms

上述log中，tag=ActivityMangager；priority=I
tag的定义在源码中定义，例如:
AudioRecord.app中
#define LOG_TAG "AudioRecord"
此文件中的LOGX打印的TAG就是AudioRecord

log级别是大于等于设定级别，LOGV对应V（Verbose）级别，LOGD对应D（Debug）级别

如果你要只输出此文件中的错误信息
则：#logcat -s AudioRecord：E
就会输出大于等于Error的log信息

同理，同时设置多个log过滤器
#logcat -s AudioRecord：E AudioTrack:V AudioFlinger:W

有问题可以留言！

//===========================================================================================

本人备注

Unrecognized Option i
Usage: logcat [options] [filterspecs]
options include:
  -s              Set default filter to silent. Equivalent to filterspec '*:S'
  -f <file>, --file=<file>               Log to file. Default is stdout
  -r <kbytes>, --rotate-kbytes=<kbytes>
                  Rotate log every kbytes. Requires -f option
  -n <count>, --rotate-count=<count>
                  Sets max number of rotated logs to <count>, default 4
  -v <format>, --format=<format>
                  Sets the log print format, where <format> is:
                    brief color epoch long monotonic printable process raw
                    tag thread threadtime time uid usec UTC year zone
  -D, --dividers  Print dividers between each log buffer
  -c, --clear     Clear (flush) the entire log and exit
                  if Log to File specified, clear fileset instead
  -d              Dump the log and then exit (don't block)
  -e <expr>, --regex=<expr>
                  Only print lines where the log message matches <expr>
                  where <expr> is a regular expression
  -m <count>, --max-count=<count>
                  Quit after printing <count> lines. This is meant to be
                  paired with --regex, but will work on its own.
  --print         Paired with --regex and --max-count to let content bypass
                  regex filter but still stop at number of matches.
  -t <count>      Print only the most recent <count> lines (implies -d)
  -t '<time>'     Print most recent lines since specified time (implies -d)
  -T <count>      Print only the most recent <count> lines (does not imply -d)
  -T '<time>'     Print most recent lines since specified time (not imply -d)
                  count is pure numerical, time is 'MM-DD hh:mm:ss.mmm...'
                  'YYYY-MM-DD hh:mm:ss.mmm...' or 'sssss.mmm...' format
  -g, --buffer-size                      Get the size of the ring buffer.
  -G <size>, --buffer-size=<size>
                  Set size of log ring buffer, may suffix with K or M.
  -L, -last       Dump logs from prior to last reboot
  -b <buffer>, --buffer=<buffer>         Request alternate ring buffer, 'main',
                  'system', 'radio', 'events', 'crash', 'default' or 'all'.
                  Multiple -b parameters or comma separated list of buffers are
                  allowed. Buffers interleaved. Default -b main,system,crash.
  -B, --binary    Output the log in binary.
  -S, --statistics                       Output statistics.
  -p, --prune     Print prune white and ~black list. Service is specified as
                  UID, UID/PID or /PID. Weighed for quicker pruning if prefix
                  with ~, otherwise weighed for longevity if unadorned. All
                  other pruning activity is oldest first. Special case ~!
                  represents an automatic quicker pruning for the noisiest
                  UID as determined by the current statistics.
  -P '<list> ...', --prune='<list> ...'
                  Set prune white and ~black list, using same format as
                  listed above. Must be quoted.
  --pid=<pid>     Only prints logs from the given pid.
  --wrap          Sleep for 2 hours or when buffer about to wrap whichever
                  comes first. Improves efficiency of polling by providing
                  an about-to-wrap wakeup.

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)

'*' by itself means '*:D' and <tag> by itself means <tag>:V.
If no '*' filterspec or -s on command line, all filter defaults to '*:V'.
eg: '*:S <tag>' prints only <tag>, '<tag>:S' suppresses all <tag> log messages.

If not specified on the command line, filterspec is set from ANDROID_LOG_TAGS.

If not specified with -v on command line, format is set from ANDROID_PRINTF_LOG
or defaults to "threadtime"