~kolletzki/bashcfg

d1f086e6d1a52366174f9527bf5e57fdcadcb6a8 — Lukas Kolletzki 4 months ago
Initial commit
3 files changed, 196 insertions(+), 0 deletions(-)

A LICENSE
A README.md
A bashcfg.sh
A  => LICENSE +25 -0
@@ 1,25 @@
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

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 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.

For more information, please refer to <http://unlicense.org/>


A  => README.md +99 -0
@@ 1,99 @@
# bashcfg
A bash function for parsing config files.

Sometimes, when bash scripts grow, you'll find yourself in the situation where
you ~~want to have~~ definitely need a config file.
But of course, you being the nerd that writes ~~too complex~~ advanced bash
scripts, you're not interested in a third-party tool for parsing said config
files.

`bashcfg` to the rescue!

It's a small(ish) bash function that you can add to your script to parse a
config file.

## Usage
Take a look at `bashcfg.sh` file and copy the function and related variables.
Read the code and adjust as necessary.

## Config file format
- All values are strings
- First `=` sign splits the key and the value
- Leading and trailing whitespace of keys and values are trimmed (whitespace around `=` is allowed)
- Lines beginning with a `#` (whitespace ignored) are comments
- Empty lines are ignored
- Should be fairly safe (does not execute subshells, etc.)
- Empty values are respected
- Lines without a delimiter (`=`) are ignored

### Example
**`myscript.conf`**
```
foo=bar
foo2 = bar2



# This is a comment
  # indented comment
#another comment

  indented = config line

some_more_weirdness    =    lots of spaces

value_with_trailing_whitespace = value with trailing whitespace   

empty=

evil = $(ping 9.9.9.9)
$(ping 1.1.1.1)
```

**output**
```
empty has the value ''
foo has the value 'bar'
bar has the value 'baz'
evil has the value '$(ping 9.9.9.9)'
some_more_weirdness has the value 'lots of spaces'
indented has the value 'config line'
foo2 has the value 'bar2'
notice_the_trailing_whitespace_of_the_value has the value 'value with trailing whitespace'

```

## Contribute
You are more than welcome to contribute to this project. Please
[send patches](https://git-send-email.io) to `~kolletzki/patches@lists.sr.ht`.
Thanks!

## License
This script is released as public domain under the [Unlicense](https://unlicense.org/).

```
This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

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 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.

For more information, please refer to <http://unlicense.org/>
```

A  => bashcfg.sh +72 -0
@@ 1,72 @@
#!/usr/bin/env bash
set -euo pipefail

CONFIG_FILE="bashcfg/bashcfg.conf"
DEFAULT_CONFIG="$(cat << EOF
# Value for Foo
foo = bar
EOF
)"

declare -A config

function load_config() {
	# Ensure that directory and file exist
	local config_home="${XDG_CONFIG_HOME:-}"
	if [[ -z "${config_home}" ]]; then
		config_home="${HOME}/.config"
	fi

	local config_dir="${config_home}/${CONFIG_FILE%/*}"
	local config_file="${CONFIG_FILE##*/}"
	if [[ ! -d "${config_dir}" ]]; then
		mkdir "${config_dir}"
	fi

	local config_path="${config_dir}/${config_file}"
	if [[ ! -f "${config_path}" ]]; then
		cat > "${config_path}" <<< "${DEFAULT_CONFIG:-}"
	fi

	function _trim_leading() {
		printf "%s" "${1#"${1%%[![:space:]]*}"}"
	}
	function _trim_trailing() {
		printf "%s" "${1%"${1##*[![:space:]]}"}"
	}

	# Read config file
	while read -r l; do
		l="$(_trim_leading "${l}")"

		# Skip comments and empty lines
		if [[ "${l:0:1}" == "#" ]] || [[ -z "${l}" ]]; then
			continue
		fi

		local key="$(cut -d "=" -f 1 <<< "${l}")"
		# Leading spaces are already trimmed from $l
		key="$(_trim_trailing "${key}")"

		# Skip lines without =
		if [[ "${key}" == "${l}" ]]; then
			continue
		fi

		local value="$(cut -d "=" -f 2- <<< "${l}")"
		value="$(_trim_leading "${value}")"
		value="$(_trim_trailing "${value}")"

		config["${key}"]="${value}"
	done < "${config_path}"

	# Ensure all config options are set or set defaults
	[[ -n "${config["foo"]:-}" ]] || ( printf "foo not set\n"; exit 1 )
	[[ -n "${config["bar"]:-}" ]] || config["bar"]="baz"
}

load_config

for k in "${!config[@]}"; do
	printf "%s has the value '%s'\n" "${k}" "${config["${k}"]}"
done