Class: ShellOpts::ShellOpts

Inherits:
Object
  • Object
show all
Defined in:
lib/shellopts.rb

Overview

The compilation object

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(usage, argv, program_name: File.basename($0)) ⇒ ShellOpts

Compile a usage string into a grammar and use that to parse command line arguments

usage is the usage string, and argv the command line (typically the global ARGV array). program_name is the name of the program and is used in error messages. It defaults to the basename of the program

Errors in the usage string raise a CompilerError exception. Errors in the argv arguments terminates the program with an error message



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# File 'lib/shellopts.rb', line 163

def initialize(usage, argv, program_name: File.basename($0))
  @program_name = program_name
  begin
    @grammar = Grammar.compile(program_name, usage)
    @ast = Ast.parse(@grammar, argv)
  rescue Grammar::Compiler::Error => ex
    raise CompilerError.new(5, ex.message)
  rescue Ast::Parser::Error => ex
    error(ex.message)
  end
end

Instance Attribute Details

#ast ⇒ Object (readonly)

The AST resulting from parsing the command line arguments



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# File 'lib/shellopts.rb', line 149

def ast
  @ast
end

#grammar ⇒ Object (readonly)

The grammar compiled from the usage string. If #ast is defined, it’s equal to ast.grammar



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# File 'lib/shellopts.rb', line 146

def grammar
  @grammar
end

#program_name ⇒ Object (readonly)

Name of program



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# File 'lib/shellopts.rb', line 139

def program_name
  @program_name
end

Instance Method Details

#args ⇒ Object

List of remaining non-option command line arguments. Shorthand for ast.arguments



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# File 'lib/shellopts.rb', line 152

def args() @ast.arguments end

#each(&block) ⇒ Object

Iterate the result as name/value pairs. See ShellOpts.process for a detailed description



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# File 'lib/shellopts.rb', line 182

def each(&block)
  if block_given?
    to_a.each { |*args| yield(*args) }
  else
    to_a # FIXME: Iterator
  end
end

#error(*msgs) ⇒ Object

Print error message and usage string and exit with status 1. This method should be called in response to user-errors (eg. specifying an illegal option)



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# File 'lib/shellopts.rb', line 193

def error(*msgs)
  ::ShellOpts.emit_and_exit(program_name, true, usage, msgs)
end

#fail(*msgs) ⇒ Object

Print error message and exit with status 1. This method should not be called in response to user-errors but system errors (like disk full)



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# File 'lib/shellopts.rb', line 199

def fail(*msgs)
  ::ShellOpts.emit_and_exit(program_name, false, nil, msgs)
end

#to_a ⇒ Object

Unroll the AST into a nested array



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# File 'lib/shellopts.rb', line 176

def to_a
  @ast.values
end

#usage ⇒ Object

Prettified usage string used by #error and #fail. Shorthand for grammar.usage



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# File 'lib/shellopts.rb', line 142

def usage() @grammar.usage end