Find a string in configured set of dirs and files.

findstr.rb

#!/usr/bin/env ruby
#
# Script to search for a string in a set of configured dirs. The main
# value of this is to provide:
#
#   * Easy configuration for a common set of directories you like to
#     grep through, and the file patterns to match per directory.
#
#   * Easy configuration for the common grep options you like to use.
#
#   * Automatically prefix dir greps with removal of files like
#     the emacs ~ files.
#
# This script assumes you are invoking this from a shell like
# bash or zsh that supports the ** glob, and that you have grep installed.
#

###############################################################################
# Usage
###############################################################################
usage=<<EOT

Usage:

  findstr.rb <string>

    <string>: The string to find in the configured set of directories.

EOT


###############################################################################
# Configuration
###############################################################################

# The grep options you prefer.
GREP_OPTS = "-li"

# Configure the dirs you want want to recursively search.
DIRS = [
  {:path => 'app',                :patterns => ["*.*"]},
  {:path => 'lib',                :patterns => ["*.*"]},
  {:path => 'public/javascripts', :patterns => ["*.*"]},
  {:path => 'public/stylesheets', :patterns => ["*.*"]},
  {:path => 'public/config',      :patterns => ["*.*"]},
  {:path => 'script',             :patterns => ["*"]},
  {:path => 'config',             :patterns => ["*.*"]},
  {:path => 'test',               :patterns => ["*.*"]},
  {:path => 'db/migrate',         :patterns => ["*.*"]},
]

# Configure the patterns for kinds of files to remove.
RM_PATTERNS = [
  '*~'
]

# Commands that are required for this script.
REQUIRED_CMDS = [
  'grep',
]


###############################################################################
# Helpers
###############################################################################

# Runs a command in a sub-shell. Mainly used to eat stout/stderr that
# comes from the shell, not the command (e.g.: nothing matches glob).
def subshell_cmd(cmd, redirs=[])
  system("#{ENV['SHELL']} -c \"#{cmd.gsub('"', '\\"')}\" #{redirs.to_a.join(' ')}")
end


###############################################################################
# Main Program
###############################################################################
if ARGV.size != 1
  puts usage
  exit -1
end
search_term = ARGV[0]

# Check for required command availability.
REQUIRED_CMDS.each do |cmd|
  if !system("which #{cmd} > /dev/null")
    puts "ERROR: You must have #{cmd} installed in your path."
    puts usage
    exit -1
  end
end

# Before we search, remove all emacs temp files.
DIRS.each do |dir|
  RM_PATTERNS.each do |pat|
    subshell_cmd("rm -f #{dir[:path].gsub(' ', '\\ ')}/**/#{pat}", "&>/dev/null")
  end
end

# Make a list of grep input files.
files = DIRS.map do |dir|
  dir[:patterns].map do |pat|
    "#{dir[:path].gsub(' ', '\\ ')}/**/#{pat}"
  end.join(' ')
end.join(' ')

# Grep for what we want.
subshell_cmd("grep #{GREP_OPTS} \"#{search_term}\" #{files}")