现在做这件事的一个快速方法(以前的方法对我没用):

sudo wget https://github.com/mikefarah/yq/releases/download/v4.4.1/yq_linux_amd64 -O /usr/bin/yq &&\
sudo chmod +x /usr/bin/yq

示例asd.yaml:

a_list:
  - key1: value1
    key2: value2
    key3: value3

解析:根

user@vm:~$ yq e '.' asd.yaml                                                                                                         
a_list:
  - key1: value1
    key2: value2
    key3: value3

解析key3:

user@vm:~$ yq e '.a_list[0].key3' asd.yaml                                                                                             
value3

如果您知道您感兴趣的标记和您期望的yaml结构，那么在Bash中编写一个简单的yaml解析器并不难。

在下面的示例中，解析器将一个结构化YAML文件读入环境变量、数组和关联数组。

注意:这个解析器的复杂性与YAML文件的结构有关。对于YAML文件的每个结构化组件，都需要一个单独的子例程。高度结构化的YAML文件可能需要更复杂的方法，例如通用的递归下降解析器。

圣诞节。yaml文件:

# Xmas YAML example
---
 # Values
 pear-tree: partridge
 turtle-doves: 2.718
 french-hens: 3

 # Array
 calling-birds:
   - huey
   - dewey
   - louie
   - fred

 # Structure
 xmas-fifth-day:
   calling-birds: four
   french-hens: 3
   golden-rings: 5
   partridges:
     count: 1
     location: "a pear tree"
   turtle-doves: two

解析器使用mapfile将文件作为数组读入内存，然后循环遍历每个标记并创建环境变量。

梨树、斑鸠和法国母鸡:最终成为简单的环境变量 呼叫鸟:变成一个数组 xmas-fifth-day:结构被表示为一个关联数组，但是如果您没有使用Bash 4.0或更高版本，您可以将这些数组编码为环境变量。 注释和空白将被忽略。

#!/bin/bash
# -------------------------------------------------------------------
# A simple parser for the xmas.yaml file
# -------------------------------------------------------------------
# 
# xmas.yaml tags
#  #                        - Ignored
#                           - Blank lines are ignored
#  ---                      - Initialiser for days-of-xmas 
#   pear-tree: partridge    - a string
#   turtle-doves: 2.718     - a string, no float type in Bash
#   french-hens: 3          - a number
#   calling-birds:          - an array of strings
#     - huey                - calling-birds[0]
#     - dewey
#     - louie
#     - fred
#   xmas-fifth-day:         - an associative array
#     calling-birds: four   - a string
#     french-hens: 3        - a number
#     golden-rings: 5       - a number
#     partridges:           - changes the key to partridges.xxx
#       count: 1            - a number
#       location: "a pear tree" - a string
#     turtle-doves: two     - a string
# 
# This requires the following routines
# ParseXMAS
#   parses #, ---, blank line
#   unexpected tag error
#   calls days-of-xmas
#
# days-of-xmas
#   parses pear-tree, turtle-doves, french-hens
#   calls calling-birds
#   calls xmas-fifth-day
# 
# calling-birds
#   elements of the array
#
# xmas-fifth-day
#   parses calling-birds, french-hens, golden-rings, turtle-doves
#   calls partridges
# 
# partridges
#   parses partridges.count, partridges.location
#

function ParseXMAS()
{

  # days-of-xmas
  #   parses pear-tree, turtle-doves, french-hens
  #   calls calling-birds
  #   calls xmas-fifth-day
  # 
  function days-of-xmas()
  {
    unset PearTree TurtleDoves FrenchHens

    while [ $CURRENT_ROW -lt $ROWS ]
    do
      LINE=( ${CONFIG[${CURRENT_ROW}]} )
      TAG=${LINE[0]}
      unset LINE[0]

      VALUE="${LINE[*]}"

      echo "  days-of-xmas[${CURRENT_ROW}] ${TAG}=${VALUE}"

      if [ "$TAG" = "pear-tree:" ]
      then
        declare -g PearTree=$VALUE
      elif [ "$TAG" = "turtle-doves:" ]
      then
        declare -g TurtleDoves=$VALUE
      elif [ "$TAG" = "french-hens:" ]
      then
        declare -g FrenchHens=$VALUE
      elif [ "$TAG" = "calling-birds:" ]
      then
        let CURRENT_ROW=$(($CURRENT_ROW + 1))
        calling-birds
        continue
      elif [ "$TAG" = "xmas-fifth-day:" ]
      then
        let CURRENT_ROW=$(($CURRENT_ROW + 1))
        xmas-fifth-day
        continue
      elif [ -z "$TAG" ] || [ "$TAG" = "#" ]
      then
        # Ignore comments and blank lines
        true
      else
        # time to bug out
        break
      fi

      let CURRENT_ROW=$(($CURRENT_ROW + 1))
    done
  }

  # calling-birds
  #   elements of the array
  function calling-birds()
  {
    unset CallingBirds

    declare -ag CallingBirds

    while [ $CURRENT_ROW -lt $ROWS ]
    do
      LINE=( ${CONFIG[${CURRENT_ROW}]} )
      TAG=${LINE[0]}
      unset LINE[0]

      VALUE="${LINE[*]}"

      echo "    calling-birds[${CURRENT_ROW}] ${TAG}=${VALUE}"

      if [ "$TAG" = "-" ]
      then
        CallingBirds[${#CallingBirds[*]}]=$VALUE
      elif [ -z "$TAG" ] || [ "$TAG" = "#" ]
      then
        # Ignore comments and blank lines
        true
      else
        # time to bug out
        break
      fi

      let CURRENT_ROW=$(($CURRENT_ROW + 1))
    done
  }

  # xmas-fifth-day
  #   parses calling-birds, french-hens, golden-rings, turtle-doves
  #   calls fifth-day-partridges
  # 
  function xmas-fifth-day()
  {
    unset XmasFifthDay

    declare -Ag XmasFifthDay

    while [ $CURRENT_ROW -lt $ROWS ]
    do
      LINE=( ${CONFIG[${CURRENT_ROW}]} )
      TAG=${LINE[0]}
      unset LINE[0]

      VALUE="${LINE[*]}"

      echo "    xmas-fifth-day[${CURRENT_ROW}] ${TAG}=${VALUE}"

      if [ "$TAG" = "calling-birds:" ]
      then
        XmasFifthDay[CallingBirds]=$VALUE
      elif [ "$TAG" = "french-hens:" ]
      then
        XmasFifthDay[FrenchHens]=$VALUE
      elif [ "$TAG" = "golden-rings:" ]
      then
        XmasFifthDay[GOLDEN-RINGS]=$VALUE
      elif [ "$TAG" = "turtle-doves:" ]
      then
        XmasFifthDay[TurtleDoves]=$VALUE
      elif [ "$TAG" = "partridges:" ]
      then
        let CURRENT_ROW=$(($CURRENT_ROW + 1))
        partridges
        continue
      elif [ -z "$TAG" ] || [ "$TAG" = "#" ]
      then
        # Ignore comments and blank lines
        true
      else
        # time to bug out
        break
      fi
 
      let CURRENT_ROW=$(($CURRENT_ROW + 1))
    done
  }

  function partridges()
  {
    while [ $CURRENT_ROW -lt $ROWS ]
    do
      LINE=( ${CONFIG[${CURRENT_ROW}]} )
      TAG=${LINE[0]}
      unset LINE[0]

      VALUE="${LINE[*]}"

      echo "      partridges[${CURRENT_ROW}] ${TAG}=${VALUE}"

      if [ "$TAG" = "count:" ]
      then
        XmasFifthDay[PARTRIDGES.COUNT]=$VALUE
      elif [ "$TAG" = "location:" ]
      then
        XmasFifthDay[PARTRIDGES.LOCATION]=$VALUE
      elif [ -z "$TAG" ] || [ "$TAG" = "#" ]
      then
        # Ignore comments and blank lines
        true
      else
        # time to bug out
        break
      fi
 
      let CURRENT_ROW=$(($CURRENT_ROW + 1))
    done
  }

  # ===================================================================
  # Load the configuration file

  mapfile CONFIG < xmas.yaml

  let ROWS=${#CONFIG[@]}
  let CURRENT_ROW=0

  # +
  # #
  #
  # ---
  # -
  while [ $CURRENT_ROW -lt $ROWS ]
  do
    LINE=( ${CONFIG[${CURRENT_ROW}]} )
    TAG=${LINE[0]}
    unset LINE[0]

    VALUE="${LINE[*]}"

    echo "[${CURRENT_ROW}] ${TAG}=${VALUE}"

    if [ "$TAG" = "---" ]
    then
        let CURRENT_ROW=$(($CURRENT_ROW + 1))
        days-of-xmas
        continue
    elif [ -z "$TAG" ] || [ "$TAG" = "#" ]
    then
        # Ignore comments and blank lines
        true
    else
        echo "Unexpected tag at line $(($CURRENT_ROW + 1)): <${TAG}>={${VALUE}}"
        break
    fi

    let CURRENT_ROW=$(($CURRENT_ROW + 1))
  done
}

echo =========================================
ParseXMAS

echo =========================================
declare -p PearTree
declare -p TurtleDoves
declare -p FrenchHens
declare -p CallingBirds
declare -p XmasFifthDay

这将产生以下输出

=========================================
[0] #=Xmas YAML example
[1] ---=
  days-of-xmas[2] #=Values
  days-of-xmas[3] pear-tree:=partridge
  days-of-xmas[4] turtle-doves:=2.718
  days-of-xmas[5] french-hens:=3
  days-of-xmas[6] =
  days-of-xmas[7] #=Array
  days-of-xmas[8] calling-birds:=
    calling-birds[9] -=huey
    calling-birds[10] -=dewey
    calling-birds[11] -=louie
    calling-birds[12] -=fred
    calling-birds[13] =
    calling-birds[14] #=Structure
    calling-birds[15] xmas-fifth-day:=
  days-of-xmas[15] xmas-fifth-day:=
    xmas-fifth-day[16] calling-birds:=four
    xmas-fifth-day[17] french-hens:=3
    xmas-fifth-day[18] golden-rings:=5
    xmas-fifth-day[19] partridges:=
      partridges[20] count:=1
      partridges[21] location:="a pear tree"
      partridges[22] turtle-doves:=two
    xmas-fifth-day[22] turtle-doves:=two
=========================================
declare -- PearTree="partridge"
declare -- TurtleDoves="2.718"
declare -- FrenchHens="3"
declare -a CallingBirds=([0]="huey" [1]="dewey" [2]="louie" [3]="fred")
declare -A XmasFifthDay=([CallingBirds]="four" [PARTRIDGES.LOCATION]="\"a pear tree\"" [FrenchHens]="3" [GOLDEN-RINGS]="5" [PARTRIDGES.COUNT]="1" [TurtleDoves]="two" )

我曾经使用python将yaml转换为json，并在jq中进行处理。

python -c "import yaml; import json; from pathlib import Path; print(json.dumps(yaml.safe_load(Path('file.yml').read_text())))" | jq '.'

把我的答案从如何在bash中将json响应转换为yaml，因为这似乎是关于从命令行处理yaml文本解析的权威帖子。

我想添加一些关于yq YAML实现的细节。由于这个YAML解析器有两种实现，名称都是yq，如果不查看实现的DSL，就很难区分使用的是哪一种。有两个可用的实现

kislyuk/yq——更常被提及的版本，它是jq的包装器，用Python编写，使用PyYAML库进行YAML解析 mikefarah/yq -一个Go实现，使用Go -yaml v3解析器，有自己的动态DSL。

几乎所有主要发行版都可以通过标准安装包管理器进行安装

kislyuk/yq -安装说明 mikefarah/yq -安装说明

这两个版本都有一些优点和缺点，但有一些有效的点需要强调(从他们的回购指令中采用)

kislyuk - yq

Since the DSL is the adopted completely from jq, for users familiar with the latter, the parsing and manipulation becomes quite straightforward Supports mode to preserve YAML tags and styles, but loses comments during the conversion. Since jq doesn't preserve comments, during the round-trip conversion, the comments are lost. As part of the package, XML support is built in. An executable, xq, which transcodes XML to JSON using xmltodict and pipes it to jq, on which you can apply the same DSL to perform CRUD operations on the objects and round-trip the output back to XML. Supports in-place edit mode with -i flag (similar to sed -i)

迈克法拉/YQ

Prone to frequent changes in DSL, migration from 2.x - 3.x Rich support for anchors, styles and tags. But lookout for bugs once in a while A relatively simple Path expression syntax to navigate and match yaml nodes Supports YAML->JSON, JSON->YAML formatting and pretty printing YAML (with comments) Supports in-place edit mode with -i flag (similar to sed -i) Supports coloring the output YAML with -C flag (not applicable for JSON output) and indentation of the sub elements (default at 2 spaces) Supports Shell completion for most shells - Bash, zsh (because of powerful support from spf13/cobra used to generate CLI flags)

我对以下两个版本的YAML的看法(在其他答案中也有引用)

root_key1: this is value one
root_key2: "this is value two"

drink:
  state: liquid
  coffee:
    best_served: hot
    colour: brown
  orange_juice:
    best_served: cold
    colour: orange

food:
  state: solid
  apple_pie:
    best_served: warm

root_key_3: this is value three

对这两个实现执行的各种操作(一些常用操作)

修改根节点值—修改“root_key2”的值 修改数组内容，增加值-为coffee添加属性 修改数组内容，删除value - Delete属性从orange_juice 打印带有路径的键/值对—用于food下的所有项目

使用kislyuk / yq

Yq -y '。Root_key2 |= "this is a new value 你，你，喝。咖啡+={时间:"always"}' yaml Yq -y 'del(.drink.orange_juice.colour)' yaml yq - r的.food |路径(标量)美元p | (($ p |加入(“。”)),(getpath ($ p) | tojson)] | @tsv的yaml

这很简单。你所需要做的就是用-y标志将jq JSON输出转码回YAML。

用mikefarah - yq

Yq w yaml root_key2 "这是一个新值" Yq w yaml喝。咖啡。时间“总是” Yq d yaml饮料。橙汁。颜色 yq r yaml——printMode pv "food.**"

截至2020年12月21日，yq v4是测试版，支持许多强大的路径表达式，并支持类似于使用jq的DSL。阅读过渡说明-从V3升级

我的用例可能与这篇原始文章所要求的完全相同，也可能不完全相同，但它肯定是相似的。

我需要拉一些YAML作为bash变量。YAML的深度永远不会超过一层。

YAML看起来是这样的:

KEY:                value
ANOTHER_KEY:        another_value
OH_MY_SO_MANY_KEYS: yet_another_value
LAST_KEY:           last_value

输出如下:

KEY="value"
ANOTHER_KEY="another_value"
OH_MY_SO_MANY_KEYS="yet_another_value"
LAST_KEY="last_value"

我用这一行实现了输出:

sed -e 's/:[^:\/\/]/="/g;s/$/"/g;s/ *=/=/g' file.yaml > file.sh

s/:[^:\/\/]/="/g查找:并将其替换为="，同时忽略://(对于url) S /$/"/g将"附加到每一行的末尾 S / *=/=/g删除=前面的所有空格

考虑到Python3和PyYAML是非常容易满足的依赖关系，下面的代码可能会有所帮助:

yaml() {
    python3 -c "import yaml;print(yaml.safe_load(open('$1'))$2)"
}

VALUE=$(yaml ~/my_yaml_file.yaml "['a_key']")