tomato-toml 0.1.0

🍅 A command-line tool to get and set values in toml files while preserving comments and formatting.
tomato-toml-0.1.0 is not a library.


Test the tomato

Get, set, and delete values in TOML files while preserving comments and formatting.

That's it. That's the feature set. I wrote tomato to satisfy my own primary use case, which is to read values of various types from a TOML preferences file, process those values in bash tooling, and infrequently update those values from other bash scripts.

An alternative tool would be dasel, if you don't need to preserve comments and formatting when you modify a value. dasel also supports a large variety of file formats.

If you need to convert among JSON, YAML, and TOML, check out jyt.


The short version:

  • Get a key: tomato <file> get <dotted.key>
  • Set a key: tomato <file> set <dotted.key> <value>
  • Delete a key: tomato <file> rm <dotted.key>

The set and rm subcommands modify the input file in place. Thanks to the magic of toml_edit, they do so without disturbing whitespace and comments.

By default tomato emits data a form suitable for immediate use in bash scripts. Strings are unquoted, for instance. The bash format generates output suitable for eval inside bash. Use this for arrays and associative arrays. If you need to consume more complex output, you might select json format and pipe the results to jq. And of course if you need TOML, use toml. The longer version:

🍅 tomato 0.1.0
A command-line tool to get and set values in toml files while preserving
comments and formatting.

Keys are written using `.` to separate path segments. You can use array[idx]
syntax to index into arrays if you want to. For example, to get the name of the
current crate you're working on, you'd run `tomato Cargo.toml get`.

By default tomato emits data in a form suitable for immediate use in bash
scripts if they are primitive values: strings are unquoted, for instance. If you
want to use more complex data types, consider one of the other output formats.


			The toml file to operate on

	-b, --backup
			Back up the file to <filepath>.bak if we write a new version

	-f, --format <FORMAT>
			How to format the output: json, toml, bash, or raw
			[default: raw]

	-h, --help
			Print help information

	-V, --version
			Print version information

	get     Get the value of a key from the given file
	help    Print this message or the help of the given subcommand(s)
	rm      Delete a key from the given file
	set     Set a key to the given value, returning the previous value if one existed

get and rm both print empty string to stdout if the target key is not found. set exits with a non-zero status with a message printed to stderr if the target key is not found.


Here are some examples run against the Cargo manifest for this project:

$ tomato Cargo.toml get
$ tomato --format json Cargo.toml get
$ tomato Cargo.toml get dependencies.toml_edit.version
$ tomato --format bash Cargo.toml get package.categories
( command-line-utilities toml )
$ tomato Cargo.toml get package.categories
( "command-line-utilities" "toml" )
$ tomato --format toml Cargo.toml get package.categories
["command-line-utilities", "toml"]
$ tomato Cargo.toml get package.categories[0]
$ tomato --format json Cargo.toml get package.categories[1]

# set examples
$ tomato Cargo.toml set broccoli
$ tomato Cargo.toml set package.categories[1] yaml

# Keys that don't exist
$ tomato Cargo.toml get dependencies.toml_edit[0]

$ tomato Cargo.toml set dependencies.toml_edit[0] "first!"
Error: unable to index into non-array at dependencies.toml_edit.0

# rm has a number of aliases to prevent user frustration
$ tomato --format json Cargo.toml del package.categories[0]

Look at the examples/ directory for some sample bash scripts using list and associate array output.


Remaining work:

  • complete the tests
    • datetimes
    • tables
    • arrays of tables


Heck, yeah! Please keep the major use case in mind: you need to read toml and do stuff with it in bash. I'm happy to accept anything that improves that use case or makes the Rust parts better.


Blue Oak Model License; text in