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Read YAML file from Bash script
MIT License
Copyright (c) 2014 Piotr Kuczynski
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#!/bin/sh
parse_yaml() {
local prefix=$2
local s='[[:space:]]*' w='[a-zA-Z0-9_]*' fs=$(echo @|tr @ '\034')
sed -ne "s|^\($s\)\($w\)$s:$s\"\(.*\)\"$s\$|\1$fs\2$fs\3|p" \
-e "s|^\($s\)\($w\)$s:$s\(.*\)$s\$|\1$fs\2$fs\3|p" $1 |
awk -F$fs '{
indent = length($1)/2;
vname[indent] = $2;
for (i in vname) {if (i > indent) {delete vname[i]}}
if (length($3) > 0) {
vn=""; for (i=0; i<indent; i++) {vn=(vn)(vname[i])("_")}
printf("%s%s%s=\"%s\"\n", "'$prefix'",vn, $2, $3);
}
}'
}
#!/bin/sh
# include parse_yaml function
. parse_yaml.sh
# read yaml file
eval $(parse_yaml zconfig.yml "config_")
# access yaml content
echo $config_development_database
development:
adapter: mysql2
encoding: utf8
database: my_database
username: root
password:
@sonisrje
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Works great.

@Nawanop-AMNB
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nice script!

@niekwit
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niekwit commented Feb 14, 2021

Works really well, thank you!

@harryberto
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description: sample message here
may overflow next line

I have a similar issue how could we store description variable that may overflow into the next line in the same

1_2_1_description="sample message here"
TO
1_2_1_description="sample message here may overflow next line"

Thank you!

@aahnik
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aahnik commented Apr 3, 2021

I think python is superior in this scripting situation. why on earth anyone would use a bash script to do such a thing? python is generally pre-installed in mac and Linux.

python is so much clean and readable.

pip install pyyaml

import yaml

FILENAME = 'your_file.yml'

with open(FILENAME) as file:
    data:dict = yaml.full_load(file)

# data is a python dictionary

@flee2free
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The traversal logic is super. Love it !! Sometimes its just fun to do these crazy stuff with Bash.

@aleon1220
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jq for JSON and yq for YAML
https://github.com/mikefarah/yq

@kokosowy
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kokosowy commented Sep 8, 2021

Hi all! This is very interested thread. Anybody knows how to make it working where string spans several lines (through "|" pipe), example:

key1: |
   1st line
   2nd line
   3rd line
key2: |
   1st line
   2nd line
   3rd line

@sonjz
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sonjz commented Oct 28, 2021

thanks for this.
added this to end after awk as a hack not to interpret $ interpolation (application: reading serverless.yml config into bash)

 | tr "$" "#" # don't want to interpret $

@Nigam8972
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i cant figure out why its not running succesfully for me whenever i execute ./test.sh it gives me error
./test.sh
./test.sh: line 4: .: parse_yaml.sh: file not found
./test.sh: line 7: parse_yaml: command not found

@Nigam8972
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has anybody else faced this issue please help

@potes74
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potes74 commented Jan 30, 2022

@Nigam8972 try with
. ./parse_yaml.sh
if they are in the same folder (it's what I use)

@ppenguin
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ppenguin commented Mar 2, 2023

Cool, just discovered this; of course the more recent suggestions are more robust and feature-rich, but I found myself needing this on constrained (i.e. busybox, sh and no python) systems where going POSIX-sh only is the way to go.

The method here by @wadewegner (or similar) to pre-process problematic keys (but not their values) was the way to go, i.e. by using "advanced" sed hold-space etc.

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