一、jq工具介绍

1. jq工具简介

jq是一款轻量级的命令行json处理工具，可以帮助用户轻松处理json格式的数据。它可以从标准输入读取json数据，也可以从文件中读取。同时，它支持各种查询和过滤操作，例如选择、过滤、转换、排序和格式化等。

2. jq工具的特点

jq是一种针对JSON格式数据处理的命令行工具，具有以下特点：

• 快速和高效：jq使用C语言编写，处理JSON数据非常快速和高效。

• 灵活和强大：jq具有丰富的功能和灵活的语法，能够处理复杂的JSON数据结构和进行高级的JSON数据操作。

• 命令行工具：jq是一个命令行工具，可从终端中直接调用，方便快捷。

• 跨平台：jq可在多种操作系统（包括Unix/Linux、Windows和macOS）上使用。

• 开源：jq是一个开源工具，用户可自由修改和分发。

• 支持管道：jq支持从一个命令输出管道到另一个命令作为输入，使得数据处理更加灵活和高效。

二、jq工具的安装

1. yum安装jq

• 需要提前安装epel源

yum install -y epel-release

• 搜索jq命令的软件包

[root@jeven ~]# yum search jq
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile* epel: mirrors.tuna.tsinghua.edu.cn
====================================================== N/S matched: jq ======================================================
drupal7-jquery_update.noarch : Upgrades the version of jQuery in Drupal core to a newer version of jQuery
jq-devel.x86_64 : Development files for jq
js-jquery-mousewheel.noarch : A jQuery plugin that adds cross-browser mouse wheel support
js-jquery-ui.noarch : jQuery user interface
js-jquery-ui-touch-punch.noarch : Touch Event Support for jQuery UI
python-XStatic-JQuery-Migrate.noarch : JQuery-Migrate (XStatic packaging standard)
python-XStatic-JQuery-TableSorter.noarch : JQuery-TableSorter (XStatic packaging standard)
python-XStatic-JQuery-quicksearch.noarch : JQuery-quicksearch (XStatic packaging standard)
python-XStatic-jQuery.noarch : jQuery 1.10.2 (XStatic packaging standard)
python-XStatic-jquery-ui.noarch : jquery-ui (XStatic packaging standard)
python-tw2-jqplugins-flot.noarch : jQuery flot (plotting) for ToscaWidgets2
python-tw2-jqplugins-gritter.noarch : jQuery gritter (growl-like pop-ups) for ToscaWidgets2
python-tw2-jqplugins-jqplot.noarch : Toscawidgets2 wrapper for the jqPlot jQuery plugin
python-tw2-jqplugins-ui.noarch : jQuery UI for ToscaWidgets2
python-tw2-jquery.noarch : jQuery for ToscaWidgets2
jq.x86_64 : Command-line JSON processor
js-jquery.noarch : JavaScript DOM manipulation, event handling, and AJAX library
js-jquery1.noarch : JavaScript DOM manipulation, event handling, and AJAX library
nodejs-extend.noarch : Port of jQuery.extend for node.js and the browser
python-pyquery.noarch : A jQuery-like library for python
python2-XStatic-DataTables.noarch : DataTables jquery javascript framework (XStatic packaging standard)
xstatic-datatables-common.noarch : DataTables jquery javascript framework (XStatic packaging standard)Name and summary matches only, use "search all" for everything.

• 安装jq工具

yum -y install jq.x86_64

• 查看jq版本

[root@docker yum.repos.d]# jq -V
jq-1.6

2. 二进制安装jq

• 下载jq工具的软件包

wget https://github.com/stedolan/jq/releases/download/jq-1.6/jq-linux64  -O   /usr/local/bin/jq

• 设置权限

chmod +x /usr/local/bin/jq

三、jq命令的使用帮助

1. 查询jq命令帮助信息

使用jq --help查询帮助信息

[root@jeven ~]# jq --help
jq - commandline JSON processor [version 1.6]Usage:	jq [options] <jq filter> [file...]jq [options] --args <jq filter> [strings...]jq [options] --jsonargs <jq filter> [JSON_TEXTS...]jq is a tool for processing JSON inputs, applying the given filter to
its JSON text inputs and producing the filter's results as JSON on
standard output.The simplest filter is ., which copies jq's input to its output
unmodified (except for formatting, but note that IEEE754 is used
for number representation internally, with all that that implies).For more advanced filters see the jq(1) manpage ("man jq")
and/or https://stedolan.github.io/jqExample:$ echo '{"foo": 0}' | jq .{"foo": 0}Some of the options include:-c               compact instead of pretty-printed output;-n               use `null` as the single input value;-e               set the exit status code based on the output;-s               read (slurp) all inputs into an array; apply filter to it;-r               output raw strings, not JSON texts;-R               read raw strings, not JSON texts;-C               colorize JSON;-M               monochrome (don't colorize JSON);-S               sort keys of objects on output;--tab            use tabs for indentation;--arg a v        set variable $a to value <v>;--argjson a v    set variable $a to JSON value <v>;--slurpfile a f  set variable $a to an array of JSON texts read from <f>;--rawfile a f    set variable $a to a string consisting of the contents of <f>;--args           remaining arguments are string arguments, not files;--jsonargs       remaining arguments are JSON arguments, not files;--               terminates argument processing;Named arguments are also available as $ARGS.named[], while
positional arguments are available as $ARGS.positional[].See the manpage for more options.

2. jq命令的选项解释

jq命令的选项解释

-c               紧凑而不是漂亮的输出;
-n               使用`null`作为单个输入值;
-e               根据输出设置退出状态代码;
-s               将所有输入读取（吸取）到数组中；应用过滤器;
-r               输出原始字符串，而不是JSON文本;
-R               读取原始字符串，而不是JSON文本;
-C               为JSON着色;
-M               单色（不要为JSON着色）;
-S               在输出上排序对象的键;
--tab            使用制表符进行缩进;
--arg a v        将变量$a设置为value<v>;
--argjson a v    将变量$a设置为JSON value<v>;
--slurpfile a f  将变量$a设置为从<f>读取的JSON文本数组;
--rawfile a f    将变量$a设置为包含<f>内容的字符串;
--args           其余参数是字符串参数，而不是文件;
--jsonargs       其余的参数是JSON参数，而不是文件;
--               终止参数处理;

四、jq命令的基本使用

1. 显示json文件的所有的key

• 查看当前测试name.json文件内容

[root@jeven ~]# cat name.json 
{"name": "John","age": 30,"city": "New York","hobbies": ["reading", "running", "traveling"],"education": {"degree": "Master's","major": "Computer Science","school": "University of California"}
}

显示json文件的所有的key

[root@jeven ~]# jq keys name.json 
["age","city","education","hobbies","name"
]

2. 显示key对应的值

• 显示某个key对应的值

[root@jeven ~]# jq .hobbies  name.json 
["reading","running","traveling"
]

• 显示所有key对应的值

[root@jeven ~]# jq .[] name.json 
"John"
"30"
"New York"
["reading","running","traveling"
]
{"degree": "Master's","major": "Computer Science","school": "University of California"
}

3. 查询json文件

查询json文件内容

[root@jeven ~]# cat name.json  |jq 
{"name": "John","age": 30,"city": "New York","hobbies": ["reading","running","traveling"],"education": {"degree": "Master's","major": "Computer Science","school": "University of California"}
}

4. 计算值的长度

计算name.json文件中值的长度

[root@jeven ~]# jq '.[] | length' name.json 
4
2
8
3
3

5. 输出美观的格式

[root@jeven ~]# echo '{ "jven": { "aa": { "bb": 123 } } }' | jq '.'
{"jven": {"aa": {"bb": 123}}
}

6. 过滤json文件中的键值

在json文件中所有值中进行过来吧内容。

[root@jeven ~]# jq .[] name.json  | grep school"school": "University of California"