Basic YAML parsing framework written in Bash
Influenced by this answer on stackoverflow this Bash script takes input configuration files formatted in YAML and outputs a dictionary with the parsed fields and values for use in other scripts. This is useful for creating wrappers for existing tools that have large and/or unintuitive CLI parameters where the inputs can easily be provided in a YAML file instead with fields of the users liking
Clone this repository
$ git clone https://github.com/gregfolker/shyml.git
Run the install script from the repository root
$ cd shyml/ && sudo ./install.sh
shyml can be run alone but isn't very useful unless the output is stored off somewhere for use by something else
$ shyml [YAML FILE] (PREFIX)
(
['field']='value'
['field_subfield']='value'
)
Example YAML file:
---
## global definitions
global:
debug: yes
verbose: no
debugging:
detailed: no
header: "debugging started"
## output
output:
file: "yes"
A value only needs to be within double quotes "" if it contains whitespace characters
The above examples/example1.yaml file will be parsed as the following:
$ shyml examples/example1.yaml
(
['global_debug']='yes'
['global_verbose']='no'
['global_debugging_detailed']='no'
['global_debugging_header']='debugging started'
['output_file']='yes'
)
See examples/ for more example YAML files and supported formats
Typically, shyml is used as the front-end to another script in order to capture inputs from the user
Example of parsing field/value pairs into a local dictionary:
declare -A inputs=$(shyml "examples/example1.yaml")
To avoid needing to pass inputs all around the script, you can dynamically define environment variables as FIELD='value'
and make them available to child processes using export
for key in ${!inputs[@]} ; do
export ${key^^}="${inputs[$key]}"
done
This will result in the following definitions globally available at runtime for the executing script:
GLOBAL_DEBUG=yes
GLOBAL_VERBOSE=no
GLOBAL_DEBUGGING_DETAILED='no'
GLOBAL_DEBUGGING_HEADER='debugging started'
OUTPUT_FILE=yes
Prefixes can optionally be added to the fields as the second argument to shyml, for example:
$ shyml examples/example1.yaml myprefix
(
['myprefix_global_debug']='yes'
['myprefix_global_verbose']='no'
['myprefix_global_debugging_detailed']='no'
['myprefix_global_debugging_header']='debugging started'
['myprefix_output_file']='yes'
)
At this time there are a few limitations with what shyml is able to parse. Pull requests are always welcome to add the necessary support
for the following items
- Field names containing whitespace characters are not supported
- Values defined as lists are not supported
- Duplicate field names are not supported
Bugs are tracked using Github