shell脚本实现格式化JSON字串---PedroQin

导言

工作中时常要上传json数据，上传前做校对时，单行的一长串json数据不方便校对，复制到 vscode中用插件实现格式化又麻烦，故有了写个脚本工具实现格式化输出json的想法。

Github

https://github.com/pedroqin/shell_script

实现效果

将单行json数据格式化为有缩进层次的多行文本。 示例：

1apple@Pedro-Mac-mini ~/D/json_tool> ./format_json.sh -f json.txt 2{ 3 "message" : "success感谢又拍云(upyun.com)提供CDN赞助", 4 "status" : 200, 5 "date" : "20200422", 6 "time" : "2020-04-22 22:22:23", 7 "cityInfo" : { 8 "city" : "天津市", 9 "citykey" : "101030100", 10 "parent" : "天津", 11 "updateTime" : "17:33" 12 }, 13 "data" : { 14 "shidu" : "8%", 15 "pm25" : 11.0, 16 "pm10" : 31.0, 17 "quality" : "优", 18 "wendu" : "15", 19 "ganmao" : "各类人群可自由活动", 20 "forecast" : [ 21 { 22 "date" : "22", 23 "high" : "高温 16℃", 24 "low" : "低温 6℃", 25 "ymd" : "2020-04-22", 26 "week" : "星期三", 27 "sunrise" : "05:26", 28 "sunset" : "18:55", 29 "aqi" : 37, 30 "fx" : "西北风", 31 "fl" : "4-5级", 32 "type" : "晴", 33 "notice" : "愿你拥有比阳光明媚的心情" 34 } 35 ], 36 "yesterday" : { 37 "date" : "21", 38 "high" : "高温 15℃", 39 "low" : "低温 6℃", 40 "ymd" : "2020-04-21", 41 "week" : "星期二", 42 "sunrise" : "05:28", 43 "sunset" : "18:54", 44 "aqi" : 60, 45 "fx" : "西北风", 46 "fl" : "5-6级", 47 "type" : "晴", 48 "notice" : "愿你拥有比阳光明媚的心情" 49 } 50 } 51}实现思路视整个json数据为一个字串，依次获取每个字符。一般使用的方式有两种如下：使用read每次获取单个字符，但需注意，使用read时需先设置$IFS(Internal Field Seprator)，否则空格会直接跳过，另还有其他一些问题，需要考虑的特殊情况较多，实现稍繁琐。1ifs_bak="$IFS" 2IFS=$'n' 3echo "$strings"|while ((1)); do 4 read -s -r -n 1 ch 5 judge_char "$ch" 6 [ -z "$ch" ] && break 7done 8IFS="$ifs_bak"使用字符串截取，无使用read时的特殊情况，推荐1offset=0 2while ((1)); do 3 ch="${strings:$offset:1}" 4 judge_char "$ch" 5 [ -z "$ch" ] && break 6 let offset++ 7done将上一步获取的字符做判断，筛选出六个构造字符（“[”、“]”、“{”、“}”、“:”、“,”），并实现对应缩进长度和换行其他注意点在json 对象和数组中的“[”、“]”、“{”、“}”、“:”、“,” 为普通字符，需加判断，本文处使用flag值做判断实现缩进的关键点在于缩进字串长度的控制，以及六个构造字符打印时伴随的换行和缩进字符的打印代码 1#!/bin/bash 2############################################### 3# Filename : format_json.sh 4# Author : PedroQin 5# Date : 2020-04-22 18:33:35 6# Description : 7# Version : 1.0.1 8############################################### 9 10# you can diy indent ,like "t or " " 11indent=" " 12 13############################################## 14indent_num=0 15indent_str="" 16double_quotes=false 17#A string is a sequence of zero or more Unicode characters, wrapped in double quotes, using backslash escapes. A character is represented as a single character string. A string is very much like a C or Java string. --- by https://www.json.org/json-en.html ,so single quote is not accepted ! 18#single_quote=false 19# show message in green 20function green_message() 21{ 22 echo -ne "33[32m$@33[0m" 23 echo 24} 25 26# show message in red 27function red_message() 28{ 29 echo -ne "33[31m$@33[0m" 30 echo 31} 32 33function judge_char() 34{ 35 case "$1" in 36 "{") 37 [ "$double_quotes" == "true" ] && echo -n "$1" && return 38 let indent_num++ 39 combining_indent + 40 echo "{" 41 echo -ne "$indent_str" 42 ;; 43 44 "}") 45 [ "$double_quotes" == "true" ] && echo -n "$1" && return 46 let indent_num-- 47 combining_indent - 48 echo 49 echo -ne "$indent_str}" 50 ;; 51 52 "[") 53 [ "$double_quotes" == "true" ] && echo -n "$1" && return 54 let indent_num++ 55 combining_indent + 56 echo "[" 57 echo -ne "$indent_str" 58 ;; 59 60 "]") 61 [ "$double_quotes" == "true" ] && echo -n "$1" && return 62 let indent_num-- 63 combining_indent - 64 echo 65 echo -ne "$indent_str]" 66 ;; 67 68 ",") 69 [ "$double_quotes" == "true" ] && echo -n "$1" && return 70 echo "," 71 echo -ne "$indent_str" 72 ;; 73 74 '"') 75 [ "$double_quotes" == "true" ] && double_quotes=false || double_quotes=true 76 echo -n '"' 77 ;; 78 79 ":") 80 [ "$double_quotes" == "false" ] && echo -n " : " || echo -n ":" 81 ;; 82 83 "\") 84 # if get ,will skip the next char, mostly it is n 85 [ "$double_quotes" == "false" ] && let offset++ || echo -n "\" 86 ;; 87 88 *) 89 echo -n "$1" 90 ;; 91 92 esac 93} 94 95function combining_indent() 96{ 97 if [ $indent_num -lt 0 ];then 98 red_message "Wrong Json format!" 99 exit 255 100 fi 101 case $1 in 102 +) 103 indent_str+=$indent 104 ;; 105 -) 106 indent_str=${indent_str%"$indent"} 107 ;; 108 109 esac 110} 111 112function usage() 113{ 114 cat << USAGE 115$0 -f $json_file 116$0 $json_str 117USAGE 118 exit 255 119} 120 121if [ "$1" == "-f" ] || [ "$1" == "--file" ];then 122 file_name=$2 123 [ ! -f "$file_name" ] && red_message "Can't find the file :$file_name" && usage 124 strings="$(cat $file_name)" 125else 126 strings="$@" 127fi 128 129offset=0 130while ((1)); do 131 ch="${strings:$offset:1}" 132 judge_char "$ch" 133 [ -z "$ch" ] && break 134 let offset++ 135done 136echo附录

获取天津15天天气JSON数据（http://t.weather.sojson.com/api/weather/city/101030100）

---来自腾讯云社区的---PedroQin