mirror of
https://github.com/antonmedv/fx
synced 2024-11-17 09:25:32 +00:00
135 lines
2.8 KiB
Markdown
135 lines
2.8 KiB
Markdown
# fx
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A non-interactive, JavaScript version of the [**fx**](https://fx.wtf).
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Short for _Function eXecution_ or _f(x)_.
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```sh
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npm i -g fx
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```
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Or use **npx**:
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```sh
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cat file.json | npx fx .field
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```
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Or use **node**:
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```sh
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cat file.json | node <(curl -s https://fx.wtf) .field
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```
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Or use **deno**:
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```sh
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cat file.json | deno run https://fx.wtf .field
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```
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## Usage
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Fx treats arguments as JavaScript functions. Fx passes the input data to the first
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function and then passes the result of the first function to the second function
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and so on.
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```sh
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echo '{"name": "world"}' | fx 'x => x.name' 'x => `Hello, ${x}!`'
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```
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Use `this` to access the input data. Use `.` at the start of the expression to
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access the input data without a `x => x` part.
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```sh
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echo '{"name": "world"}' | fx '.name' '`Hello, ${this}!`'
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```
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Use other JS functions to process the data.
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```sh
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echo '{"name": "world"}' | fx 'Object.keys'
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```
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## Advanced Usage
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Fx can process a stream of json objects. Fx will apply arguments to each object.
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```sh
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echo '{"name": "hello"}\n{"name": "world"}' | fx '.name'
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```
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If you want to process a stream of json objects as a single array,
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use the **--slurp** or **-s** flag.
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```sh
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echo '{"name": "hello"}\n{"name": "world"}' | fx --slurp '.map(x => x.name)' '.join(", ")'
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```
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If you want to process non-JSON data, use the **--raw** or **-r** flag.
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```sh
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ls | fx -r '[this, this.includes(".md")]'
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```
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You can use **--raw** and **--slurp** (or **-rs**) together to get a single array of strings.
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```sh
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ls | fx -rs '.filter(x => x.includes(".md"))'
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```
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Fx has a special symbol **skip** for skipping the printing of the result.
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```sh
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ls | fx -r '.includes(".md") ? this : skip'
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```
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Fx comes with a set of useful functions: **uniq**, **sort**, **groupBy**, **chunk**, **zip**.
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```sh
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cat file.json | fx 'uniq' 'sort' 'groupBy(x => x.name)'
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```
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Fx works with promises.
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```sh
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echo '"https://medv.io/*"' | fx 'fetch' '.text()'
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```
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### Syntactic Sugar
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Fx has a shortcut for the map function. Fox example, `this.map(x => x.commit.message)`
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can be rewritten without leading dot and without `x => x` parts.
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```sh
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curl https://api.github.com/repos/antonmedv/fx/commits | fx 'map(.commit.message)'
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```
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```sh
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echo '[{"name": "world"}]' | fx 'map(`Hello, ${x.name}!`)'
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```
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Fx has a special syntax for the flatMap function. Fox example,
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`.flatMap(x => x.labels.flatMap(x => x.name))` can be rewritten in the next way.
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```sh
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curl https://api.github.com/repos/kubernetes/kubernetes/issues | fx '.[].labels[].name'
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```
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### .fxrc.js
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Fx supports `.fxrc.js` file in the current directory or in the home directory.
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Put the next code in the `.fxrc.js` file to make `myFunction` available in the fx.
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```js
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global.myFunction = x => x + 1
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```
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Now you can use `myFunction` in the fx.
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```sh
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echo '1' | fx 'myFunction'
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```
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## License
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[MIT](../LICENSE)
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