DZone Snippets: shell code

simple init.d script for django using fastcgi

stvnz (Steven) — Tue, 15 Jul 2008 23:01:13 GMT



#!/bin/sh

#

# chkconfig:	345 85 15

# description:	FastCGI server for Django





# Source function library

. /etc/rc.d/init.d/functions



# Source networking configuration.

. /etc/sysconfig/network



# Check that networking is up.

[ "${NETWORKING}" = "no" ] && exit 0



PROJ=myproject					# Django project name

PROJSPATH=/home/user/www			# The folder Django project is in

SOCKSPATH=/tmp					# Where you put UNIX socket file

PIDSPATH=/var/run				# Where you put .pid file

RUNAS=root					# Set a different user to run the FastCGI server



SRVNAME=fcgi-$PROJ				# Process name



# Maximum requests for a child to service before expiring

#MAXREQ=

# Spawning method - prefork or threaded

#METHOD=

# Maximum number of children to have idle

#MAXSPARE=

# Minimum number of children to have idle

#MINSPARE=

# Maximum number of children to spawn

#MAXCHILDREN=



start () {

	# Check if the service is already running?

	if [ ! -f $PIDSPATH/$SRVNAME.pid ]; then

		echo -n $"Starting $SRVNAME..."

		daemon --user $RUNAS $PROJSPATH/$PROJ/manage.py runfcgi pidfile=$PIDSPATH/$SRVNAME.pid \

			socket=$SOCKSPATH/$SRVNAME.sock \

			${MAXREQ:+maxrequests=$MAXREQ} \

			${METHOD:+method=$METHOD} \

			${MAXSPARE:+maxspare=$MAXSPARE} \

			${MINSPARE:+minspare=$MINSPARE} \

			${MAXCHILDREN:+maxchildren=$MAXCHILDREN} \

			${DAEMONISE:+damonize=True}

		echo

		chmod 777 $SOCKSPATH/$SRVNAME.sock

		RETVAL=$?

	else

		echo $"$SRVNAME is already running."

	fi

}



stop() {

	# Stop daemons.

	if [ -f $PIDSPATH/$SRVNAME.pid ]; then

		echo -n $"Stopping $SRVNAME..."

		killproc -p "$PIDSPATH/$SRVNAME.pid" -d 60 $SRVNAME

		echo

		# Delete pidfile only when Django was called successfully

		if [ $? -eq 0 ]; then

			rm -f $PIDSPATH/$SRVNAME.pid "$SRVNAME.pid"  >/dev/null 2>&1

		fi

	else

		echo $"$SRVNAME is NOT running."

	fi



}



RETVAL=0



case "$1" in

	start)

		start

		;;

	stop)

		stop

		;;

	status)

		status -p "$PIDSPATH/$SRVNAME.pid" $SRVNAME

		RETVAL=$?

		;;

	restart)

		stop

		start

		;;

	*)

		echo $"Usage: $0 {start|stop|restart|status}"

		exit 3

		;;

esac



exit $RETVAL

Detecting bluetooth devices with hcitool scan

jrobertson (James Robertson) — Sun, 13 Jul 2008 22:31:47 GMT

A trivial Ruby script to store the bluetooth devices found with the shell command 'hcitool scan'.



#!/usr/bin/ruby



#file: bt_scan.rb



require 'rexml/document'

include REXML



while true

  filein = File.new('bt_found.xml','r')

  doc = Document.new(filein)

  filein.close



  fileout = File.new('bt_found.xml','w')



  result = `hcitool scan`

  found = result.split(/\n/) # retrieve each found device

  found.delete_at(0)         # remove the item containing 'scanning ...'



  found.each do |b|

    node_found = Element.new('found')

    p = b.split(/\t/) # retrieve device details

    id = p[1]

    name = p[2]

    puts "name #{name} --- id #{id}"

    node_id = Element.new('id')

    node_name = Element.new('name')

    node_date = Element.new('date')



    node_id.text = id

    node_name.text = name

    node_date.text = Time.now



    node_found << node_id

    node_found << node_name

    node_found << node_date

    doc.root << node_found

  end





  fileout.puts doc

  fileout.close

  puts 'sleeping'

  sleep 10 # during this time we can kill the script, 

           # otherwise we risk losing the contents of the xml file.

  puts 'awake'

end

Note: Shell commands don't really have much to do with Ruby, however if there is no easy to use bluetooth libraries then I will of course use what's available.

Monitor disk usage with a simple Ruby script

jrobertson (James Robertson) — Thu, 10 Jul 2008 12:40:28 GMT



dev = 'sda1'

report = `df -h`

disk_remaining = report[/sda\w+\s+\d+?.?\dG\s+\d+?.?\dG\s+(\d+.?\d+?G)/,1]

puts "running low on disk space (#{dev}: #{disk_remaining })" if disk_remaining.to_i < 3

Inspect a website like a string in Ruby

ntk () — Wed, 09 Jul 2008 21:13:48 GMT

Put the following function into your ~/.bash_login (or alternatives).



unset -f inspect_url



function inspect_url() { 

   /usr/bin/curl -L -s --max-time 10 "${@}" | ruby -n -e 'p $_.to_s'

   return 0

}



inspect_url http://www.ruby-forum.com

Play audio with a Ruby shell script

jrobertson (James Robertson) — Wed, 09 Jul 2008 19:15:45 GMT

Play an ogg file from the command-line using the program ogg123 from the software package 'vorbis-tools'.



#!/usr/bin/ruby



#file: ogg-play.rb



`ogg123 #{ARGV[0]} > /dev/null 2>&1`

e.g.



wget http://upload.wikimedia.org/wikipedia/en/4/4d/Elo_blue_sky.ogg

./ogg-play.rb Elo_blue_sky.ogg

Compile & install Nginx web server

ntk () — Wed, 18 Jun 2008 20:03:18 GMT

Requirement on Mac OS X: Xcode



# See:

# - http://en.wikipedia.org/wiki/Nginx

# - http://wiki.codemongers.com/NginxGettingStarted

# - http://wiki.codemongers.com/NginxInstallOptions

# - http://wiki.codemongers.com/NginxCommandLine

# - http://wiki.codemongers.com/NginxConfiguration



export PATH="/usr/local/bin:/usr/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin"



mkdir -p ~/Desktop/Nginx

cd ~/Desktop/Nginx



curl -L -O http://sysoev.ru/nginx/nginx-0.7.2.tar.gz

tar -xzf nginx-0.7.2.tar.gz



curl -L -O http://downloads.sourceforge.net/pcre/pcre-7.7.tar.gz

tar -xzf pcre-7.7.tar.gz



cd ~/Desktop/Nginx/nginx-0.7.2

./configure --help

./configure --prefix=/usr/local/nginx --sbin-path=/usr/local/sbin --with-debug --with-http_ssl_module --with-pcre=../pcre-7.7

make

sudo make install





which nginx

otool -L /usr/local/sbin/nginx

open /usr/local/nginx

open -e /usr/local/nginx/conf/nginx.conf



nginx -v

nginx -V

sudo nginx   # start server

sudo nginx -t



open http://localhost:80

open http://localhost:80/50x.html



sudo nano /usr/local/nginx/conf/nginx.conf   # editing ... server {  listen  8080; ... 



# reload configuration

sudo kill -HUP `cat /usr/local/nginx/logs/nginx.pid`  



# stop server

sudo kill -15 $(ps -auxxx | egrep "[n]ginx.*master" | awk '{ print $2 }') 2>/dev/null

Basic WEBrick setup for local web server

ntk () — Tue, 17 Jun 2008 17:27:02 GMT

Put the following functions and aliases into your ~/.bash_login (or alternatives).





unset -f webrick_local



function webrick_local() { 



   declare root_dir="${HOME}/Desktop/www"



   /bin/mkdir -p "${root_dir}/WEBrickLog"

   /bin/chmod 0754 "${root_dir}" "${root_dir}/WEBrickLog"



   /usr/bin/touch "${root_dir}/WEBrickLog/webrick.pid" "${root_dir}/WEBrickLog/webrick_ruby.pid"

   /bin/chmod 0644 "${root_dir}/WEBrickLog/webrick.pid" "${root_dir}/WEBrickLog/webrick_ruby.pid"



#   /usr/bin/touch "${root_dir}/index.html"

#   /bin/chmod 0754 "${root_dir}/index.html"





/usr/local/bin/ruby <<-HEREDOC



   require 'webrick'

   require 'webrick/accesslog'

   include WEBrick



   require 'thread'

   require 'pp'



   root_dir = "${root_dir}"

   http_dir = File.expand_path(root_dir)



   File.open(http_dir + "/WEBrickLog/webrick_ruby.pid", "w") do |f|

      f.puts(Process.pid)

   end



   # cf. http://microjet.ath.cx/webrickguide/html/Logging.html

   webrick_log_file = File.expand_path(http_dir + "/WEBrickLog/webrick.log")

   #webrick_log_file = '/dev/null'  # disable logging

   webrick_logger = WEBrick::Log.new(webrick_log_file, WEBrick::Log::DEBUG)



   access_log_stream = webrick_logger

   access_log = [[ access_log_stream, WEBrick::AccessLog::COMBINED_LOG_FORMAT ]]



   system_mime_table = WEBrick::HTTPUtils::load_mime_types('/private/etc/httpd/mime.types.default')

   system_mime_table.store('rhtml', 'text/html')   # add a mime type for .rhtml files

   system_mime_table.store('php', 'text/html')

   system_mime_table.store('rb', 'text/plain')

   system_mime_table.store('pid', 'text/plain')

   #pp system_mime_table.sort_by { |k,v| k }



   server = WEBrick::HTTPServer.new(

     :BindAddress     =>    "localhost",

     :Port            =>    9090,

     :DocumentRoot    =>    http_dir,

     :FancyIndexing   =>    true,

     :MimeTypes       =>    system_mime_table,

     :Logger          =>    webrick_logger,

     :AccessLog       =>    access_log

   )



   server.config.store(:DirectoryIndex, server.config[:DirectoryIndex] << "default.htm")

   #pp server.config



   # cf. http://snippets.dzone.com/posts/show/5208

   class TimeServlet < HTTPServlet::AbstractServlet



      def do_GET(req, res)

         res['Content-Type'] = 'text/html'

         res.status = 200

         res.body = "Time: #{Time.now.to_s}" + "\n"

      end



      # cf. http://www.hiveminds.co.uk/node/244, published under the

      # GNU Free Documentation License, http://www.gnu.org/copyleft/fdl.html



      @@instance = nil

      @@instance_creation_mutex = Mutex.new



      def self.get_instance(config, *options)

         #pp @@instance

         @@instance_creation_mutex.synchronize { 

            @@instance = @@instance || self.new(config, *options) }

      end



   end





   # cf. http://ttripp.blogspot.com/2007/01/fun-with-http.html

   class PostDumper < WEBrick::HTTPServlet::AbstractServlet

  

      # Reload file for each request, instantly

      # updating the server with code changes 

      # without needing a restart.



=begin

      def PostDumper.get_instance( config, *options )

         load __FILE__

         PostDumper.new config, *options

      end

=end



      # cf. http://www.hiveminds.co.uk/node/244, published under the

      # GNU Free Documentation License, http://www.gnu.org/copyleft/fdl.html



      @@instance = nil

      @@instance_creation_mutex = Mutex.new



      def self.get_instance(config, *options)

         #pp @@instance

         @@instance_creation_mutex.synchronize { 

            @@instance = @@instance || self.new(config, *options) }

      end



      def do_GET( request, response )

         response.status = 200

         response['Content-Type'] = "text/plain"

         response.body = dump_request( request )

      end

  

      def do_POST( request, response )

         response.status = 200

         response['Content-Type'] = "text/plain"

         response.body = dump_request( request )

         response.body << request.body

      end

  

      def dump_request( request )

         request.request_line << "\r\n" <<

         request.raw_header.join( "" ) << "\r\n"

      end

   end



   server.mount("/dump", PostDumper)

   server.mount("/time", TimeServlet, {:FancyIndexing=>true})



   # handle signals

   %w(INT).each do |signal|

      trap(signal) { server.shutdown }

   end



   server.start



HEREDOC



return 0



}



export -f webrick_local



# start WEBrick alias

alias webrick='swr'



# start WEBrick

unset -f swr

function swr() {   

  declare webrick_pid_file="${HOME}/Desktop/www/WEBrickLog/webrick.pid"

  if [[ -e "${webrick_pid_file}" ]]; then echo "WEBrick already started!"; return 1; fi

  /bin/bash -c "webrick_local" &

  declare WEBRICKPID=$!

  mkdir -p "${HOME}/Desktop/www/WEBrickLog"

  echo $WEBRICKPID > "${HOME}/Desktop/www/WEBrickLog/webrick.pid"

  return 0

}

export -f swr



# quit WEBrick

unset -f qwr

function qwr() { 

   declare webrick_pid_file="${HOME}/Desktop/www/WEBrickLog/webrick.pid"

   declare webrick_ruby_pid_file="${HOME}/Desktop/www/WEBrickLog/webrick_ruby.pid"

   if [[ ! -e "${webrick_pid_file}" ]]; then echo "no such file: ${webrick_pid_file}"; return 1; fi

   declare PIDW=$(cat "${webrick_pid_file}" 2>/dev/null)

   declare PIDR=$(cat "${webrick_ruby_pid_file}" 2>/dev/null)

   kill -INT $PIDW 2>/dev/null || echo "no such PIDW: ${PIDW}"

   kill -INT $PIDR 2>/dev/null || echo "no such PIDR: ${PIDR}"

   rm -f "${webrick_pid_file}" "${webrick_ruby_pid_file}"

   return 0

}

export -f qwr



# quit WEBrick; cf. Job Control Commands, http://tldp.org/LDP/abs/html/x8816.html

###alias qwr='echo "quit WEBrick with ctrl-c ..."; fg %webrick 2>/dev/null'



alias openwww='/usr/bin/open http://localhost:9090'

alias wrlog='/usr/bin/open http://localhost:9090/WEBrickLog/webrick.log'





#----------------------------------------





source ~/.bash_login



webrick



openwww

wrlog

open http://localhost:9090 

open http://localhost:9090/WEBrickLog

open http://localhost:9090/WEBrickLog/webrick.log



open http://localhost:9090/time

open http://localhost:9090/dump



wrlog

qwr

Further information:

- WEBrick
- WEBrick RDoc
- What is WEBrick?
- Guide to using WEBrick for Rails development
- Dynamic WEBrick Servers in Ruby
- Gnome's Guide to WEBrick
- Running Servlets with WEBrick
- rsphandler
- URL rewriting with WEBrick

Shell script to make lists of certain file types in a web site file system

johnloy (John Loy) — Sat, 31 May 2008 20:00:15 GMT

mkdir file_lists
find . -name '*.pdf' -o -name '*.PDF' > ./file_lists/all_pdf_files.txt
find . -name '*.pdf' -o -name '*.PDF' -mtime +365 > ./file_lists/pdf_files_mtime_gt_1yr.txt

find . -name '*.jpg' -o -name '*.JPG' -o -name '*.gif' -o -name '*.GIF' -o -name '*.png' -o -name '*.PNG' > ./file_lists/all_image_files.txt

find . -name '*.log' -o -name '*.LOG' > ./file_lists/all_log_files.txt

find . -name '*.css' -o -name '*.CSS' -o -name '*.js' -o -name '*.JS' > ./file_lists/all_design_assets_files.txt

find . -name '*.ram' -o -name '*.RAM' -o -name '*.aif' -o -name '*.AIF' -o -name '*.mp3' -o -name '*.MP3' > ./file_lists/all_audio_files.txt
find . -name '*.ram' -o -name '*.RAM' -o -name '*.aif' -o -name '*.AIF' -o -name '*.mp3' -o -name '*.MP3' -mtime +365 > ./file_lists/audio_files_mtime_gt_1yr.txt

find . -name '*.html' -o -name '*.HTML' -o -name '*.htm' -o -name '*.HTM' > ./file_lists/all_html_files.txt
find . -name '*.html' -o -name '*.HTML' -o -name '*.htm' -o -name '*.HTM' -mtime +365 > ./file_lists/html_files_mtime_gt_1yr.txt

Use rsync to mirror directories between Virtual Hosts.

jrobertson (James Robertson) — Thu, 29 May 2008 23:16:58 GMT

The following shell command will rsync the mysite.com directory 'feed' to mysite2.com



rsync -a /var/www/mysite.com/feed /var/www/mysite2.com

Inplace substitutions

remvee (Remco van 't Veer) — Wed, 28 May 2008 07:52:09 GMT

Place all occurrences of "old value" with "new value" in all txt files.



ruby -p -i -e '$_.gsub!("old value", "new value")' *.txt