用SQL查Linux日志工具-q

标签：-- double quoting Linux 查询 column SQL output 日志

概述

Linux文本查找命令不要太多：tail、head、cat、sed、more、less、awk，但对新手不友好。

q是一个命令行工具，允许在任意文件或查询结果，如ps -ef查询进程命令的结果集上，执行SQL语句查询。
GitHub 官方文档：https://harelba.github.io/q

理念：文本即数据库表，将普通文件或者结果集当作数据库表，几乎支持所有的SQL结构和关键词，如WHERE、GROUP BY、JOINS等，支持自动列名和列类型检测，跨文件连接查询，和多种编码。

安装

参考：installation手册。

Linux

CentOS环境：

# 下载
wget https://github.com/harelba/q/releases/download/1.7.1/q-text-as-data-1.7.1-1.noarch.rpm
# 安装
sudo rpm -ivh q-text-as-data-1.7.1-1.noarch.rpm
# 验证
q --version

Windows

当前最新版exe下载地址，一路next即可：

用SQL查Linux日志工具-q_sql

使用

q -h得到命令使用手册。支持所有SQLite SQL语法，标准命令行格式，q + 参数命令 + “SQL”：q <命令> "<SQL>" 查询文件内容：q "SELECT * FROM myfile.log" 利用参数会让显示结果更加美观，参数有2类：

input输入命令：对要查询的文件或结果集进行操作，如-H命令表示输入的数据包含标题行。
q -H "SELECT * FROM myfile.log" 在这种情况下，将自动检测列名，并可在查询语句中使用。如果未提供此选项，则列将自动命名为cX，以c1起始以此类推。
q "select c1，c2 from ..."
output输出命令：作用在查询输出的结果集，如-O让查询出来的结果显示列名：
ps -ef | q -H -O "select count(UID) from - where UID='root'" 具体Input命令参数讲解：

Input Data Options:
    -H, --skip-header   Skip header row. This has been changed from earlier
                        version - Only one header row is supported, and the
                        header row is used for column naming
    -d DELIMITER, --delimiter=DELIMITER
                        Field delimiter. If none specified, then space is used
                        as the delimiter.
    -p, --pipe-delimited
                        Same as -d '|'. Added for convenience and readability
    -t, --tab-delimited
                        Same as -d <tab>. Just a shorthand for handling
                        standard tab delimited file You can use $'\t' if you
                        want (this is how Linux expects to provide tabs in the
                        command line
    -e ENCODING, --encoding=ENCODING
                        Input file encoding. Defaults to UTF-8. set to none
                        for not setting any encoding - faster, but at your own
                        risk...
    -z, --gzipped       Data is gzipped. Useful for reading from stdin. For
                        files, .gz means automatic gunzipping
    -A, --analyze-only  Analyze sample input and provide information about
                        data types
    -m MODE, --mode=MODE
                        Data parsing mode. fluffy, relaxed and strict. In
                        strict mode, the -c column-count parameter must be
                        supplied as well
    -c COLUMN_COUNT, --column-count=COLUMN_COUNT
                        Specific column count when using relaxed or strict
                        mode
    -k, --keep-leading-whitespace
                        Keep leading whitespace in values. Default behavior
                        strips leading whitespace off values, in order to
                        provide out-of-the-box usability for simple use cases.
                        If you need to preserve whitespace, use this flag.
    --disable-double-double-quoting
                        Disable support for double double-quoting for escaping
                        the double quote character. By default, you can use ""
                        inside double quoted fields to escape double quotes.
                        Mainly for backward compatibility.
    --disable-escaped-double-quoting
                        Disable support for escaped double-quoting for
                        escaping the double quote character. By default, you
                        can use \" inside double quoted fields to escape
                        double quotes. Mainly for backward compatibility.
    --as-text           Don't detect column types - All columns will be
                        treated as text columns
    -w INPUT_QUOTING_MODE, --input-quoting-mode=INPUT_QUOTING_MODE
                        Input quoting mode. Possible values are all, minimal
                        and none. Note the slightly misleading parameter name,
                        and see the matching -W parameter for output quoting.
    -M MAX_COLUMN_LENGTH_LIMIT, --max-column-length-limit=MAX_COLUMN_LENGTH_LIMIT
                        Sets the maximum column length.
    -U, --with-universal-newlines
                        Expect universal newlines in the data. Limitation: -U
                        works only with regular files for now, stdin or .gz
                        files are not supported yet.

具体Output命令参数讲解：

Output Options:
    -D OUTPUT_DELIMITER, --output-delimiter=OUTPUT_DELIMITER
                        Field delimiter for output. If none specified, then
                        the -d delimiter is used if present, or space if no
                        delimiter is specified
    -P, --pipe-delimited-output
                        Same as -D '|'. Added for convenience and readability.
    -T, --tab-delimited-output
                        Same as -D <tab>. Just a shorthand for outputting tab
                        delimited output. You can use -D $'\t' if you want.
    -O, --output-header
                        Output header line. Output column-names are determined
                        from the query itself. Use column aliases in order to
                        set your column names in the query. For example,
                        'select name FirstName,value1/value2 MyCalculation
                        from ...'. This can be used even if there was no
                        header in the input.
    -b, --beautify      Beautify output according to actual values. Might be
                        slow...
    -f FORMATTING, --formatting=FORMATTING
                        Output-level formatting, in the format X=fmt,Y=fmt
                        etc, where X,Y are output column numbers (e.g. 1 for
                        first SELECT column etc.
    -E OUTPUT_ENCODING, --output-encoding=OUTPUT_ENCODING
                        Output encoding. Defaults to 'none', leading to
                        selecting the system/terminal encoding
    -W OUTPUT_QUOTING_MODE, --output-quoting-mode=OUTPUT_QUOTING_MODE
                        Output quoting mode. Possible values are all, minimal,
                        nonnumeric and none. Note the slightly misleading
                        parameter name, and see the matching -w parameter for
                        input quoting.
    -L, --list-user-functions
                        List all user functions

实战

关键字查询

查询时必须指定某一列：

q "select * from douyin.log where c9 like '%待解析%'"
2021-06-11 14:46:49.323 INFO 22790 --- [nio-8888-exec-2] c.x.douyin.controller.ParserController : 待解析URL :url=https%3A%2F%2Fv.douyin.com%2Fe9g9uJ6%2F

用grep命令则是全文检索：

cat douyin.log | grep '待解析URL'
2021-06-11 14:46:49.323  INFO 22790 --- [nio-8888-exec-2] c.x.douyin.controller.ParserController   : 待解析URL :url=https%3A%2F%2Fv.douyin.com%2Fe9g9uJ6%2F

模糊查询

like模糊搜索，如果文本内容列有名字直接用列名检索，没有则直接根据列号c1、c2、cN。
q -H -t "select * from test.log where abc like '%2%'"

交集并集

支持UNION和UNION ALL操作符对多个文件取交集或者并集。
q -H -t "select * from test.log union select * from test1.log"

内容去重

比如统计某个路径下的./clicks.csv文件中，uuid字段去重后出现的总个数。
q -H -t "SELECT COUNT(DISTINCT(uuid)) FROM ./clicks.csv"

列类型自动检测

q会理解每列是数字还是字符串，判断是根据实数值比较，还是字符串比较进行过滤，这里会用到-t命令。
q -H -t "SELECT request_id,score FROM ./clicks.csv WHERE score > 0.7 ORDER BY score DESC LIMIT 5"

字段运算

读取系统命令查询结果，计算/tmp目录中每个用户和组的总值，可对字段进行运算处理。

sudo find /tmp -ls | q "SELECT c5,c6,sum(c7)/1024.0/1024 AS total FROM - GROUP BY c5,c6 ORDER BY total desc"
# sudo find /tmp -ls | q "SELECT c5,c6,sum(c7)/1024.0/1024 AS total FROM - GROUP BY c5,c6 ORDER BY total desc"
www www 8.86311340332
root root 0.207922935486
mysql mysql 4.76837158203e-06

数据统计

统计系统拥有最多进程数的前 3个用户ID，按降序排序，需要配合系统命令使用，先查询所有进程再利用SQL筛选，q相当于grep：

ps -ef | q -H "SELECT UID,COUNT(*) cnt FROM - GROUP BY UID ORDER BY cnt DESC LIMIT 3"
root 104
www 16
rabbitmq 4
ps -ef | q -H -O "SELECT UID,COUNT(*) cnt FROM - GROUP BY UID ORDER BY cnt DESC LIMIT 3"
UID cnt
root 110
www 16
rabbitmq 4

加与不加-O命令的区别就是否显示查询结果的标题。

连接文件

一般情况下，日志文件会按天分割成很多个固定容量的子文件，在没有统一的日志收集服务器的情况下。可将所有文件内容合并后再查询：
q -H "select * from douyin.log a join douyin-2021-06-18.0.log b on (a.c2=b.c3) where b.c1='root'"

标签：--,double,quoting,Linux,查询,column,SQL,output,日志
From： https://blog.51cto.com/u_15851118/5807207

概述

安装