Class: Computer::Shell

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

Overview

use nested class for “base” for running commands - why? why not?

Class Method Summary collapse

Class Method Details

.call(cmd) ⇒ Object

use call for the “to-the-metal” command execution



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# File 'lib/computer/shell.rb', line 15

def self.call( cmd )
  stdout, stderr, status = Open3.capture3( cmd )
  [stdout, stderr, status]
end

.run(cmd) ⇒ Object

use run for “porcelain / high-level” command execution



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# File 'lib/computer/shell.rb', line 22

def self.run( cmd )
  ## add pwd (print working directory to output?) - why? why not?
  print "---> (shell run) >#{cmd}<..."
  stdout, stderr, status = Open3.capture3( cmd )

  ## todo: add colors (red, green) - why? why not?
  if status.success?
    print " OK"   ## todo/check: use OK (0) - why? why not?
    print "\n"
  else
    print " FAIL (#{status.exitstatus})"
    print "\n"
  end

  unless stdout.empty?
    puts stdout
  end

  unless stderr.empty?
    ## todo/check: or use >2: or &2: or such
    ##  stderr output not always an error (that is, exit status might be 0)
    STDERR.puts "2>"
    STDERR.puts stderr
  end

  if status.success?
    stdout   # return stdout string
  else
    STDERR.puts "!! ERROR: Shell.run >#{cmd}< failed with exit status #{status.exitstatus}:"
    STDERR.puts stderr

    raise ShellError, "Shell.run >#{cmd}< failed with exit status #{status.exitstatus}<: #{stderr}"
  end
end