mattes

if _, err := os.Stat("/path/to/whatever"); os.IsNotExist(err) {
	// path/to/whatever does not exist
}

if _, err := os.Stat("/path/to/whatever"); !os.IsNotExist(err) {
	// path/to/whatever exists
}

quwubin

#!/usr/bin/bash

# Give all CPUs usage percent
ps fuxw | awk '{ if ($3 ~ /^[0-9]/) {SUM +=$3}} END  {print SUM"%"}'

quwubin

#!/usr/bin/env ruby
#
# Wubin Qu <quwubin@gmail.com>
#

if ARGV.size != 1
  $stderr.puts "
  Remove blank lines and leading ^M characters

  Usage:

JosephPecoraro

# Ways to execute a shell script in Ruby
# Example Script - Joseph Pecoraro

cmd = "echo 'hi'" # Sample string that can be used

# 1. Kernel#` - commonly called backticks - `cmd` 
# This is like many other languages, including bash, PHP, and Perl
#   Synchronous (blocking)
#   Returns the output of the shell command
#   Docs: http://ruby-doc.org/core/classes/Kernel.html#M001111