https://github.com/arcage/pipeline

Line by line text processor for crystal
https://github.com/arcage/pipeline

Last synced: about 2 months ago
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Line by line text processor for crystal

• Host: GitHub
• URL: https://github.com/arcage/pipeline
• Owner: arcage
• License: mit
• Created: 2016-12-27T04:53:13.000Z (about 8 years ago)
• Default Branch: master
• Last Pushed: 2016-12-27T14:43:57.000Z (about 8 years ago)
• Last Synced: 2024-10-25T01:36:39.502Z (3 months ago)
• Language: Crystal
• Size: 2.93 KB
• Stars: 3
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Pipeline Command for Crystal

Line by line text processor for console command mainly using with pipes('|').

## Installation

Add this to your application's `shard.yml`:

```yaml

dependencies:

  pipeline:

    github: arcage/pipeline

```

## Usage

Inherit the `Pipeline::Command` class and implement `#proc(line : String)` method on it.

```crystal

# up_case.cr

require "pipeline"

class UpCase < Pipeline::Command

  def proc(line : String)

    line.upcase

  end

end

UpCase.new.run

```

```shell

% crystal up_case.cr

abc def  <- INPUT

ABC DEF  <- OUTPUT

% cat input.txt

input text file

% crystal up_case.cr -- input.txt

INPUT TEXT FILE

```

Default input and ouput are `ARGF` and `STDOUT` respectivery.

You can specify other input or output by calling '#run' method with `input` or `output` argument.

```crystal

File.open("input.txt") do |file|

  UpCase.new.run(input: file)

end

#output: INPUT TEXT FILE

```

Override `#initialize` and call `super(&block)`, then you can set flags for the internal `OptionParser` object in the block.

```crystal

# up_or_camel_case.cr

require "pipeline"

class UpOrCamelCase < Pipeline::Command

  def initialize

    @camelcase = false

    super() do

      # Default receiver in this block is the internal OpttionParser object.

      on("-c", "camel case") { @camelcase = true }

    end

  end

  def proc(line : String) : String

    @camelcase ? line.camelcase : line.upcase

  end

end

UpOrCamelCase.new.run

```

```shell

% crystal up_or_camel_case.cr

abc def  <- INPUT

ABC DEF  <- OUTPUT

^D

% crystal up_or_camel_case.cr -- -c

abc def  <- INPUT

AbcDef   <- OUTPUT

^D

```

## Contributors

- [arcage](https://github.com/arcage) ʕ·ᴥ·ʔAKJ - creator, maintainer