Spot Notes

UploadLog

Fri, 17 Jun 2011 13:19:33 GMT

date	user	location	storeUrl	uploadDir	toFilename	backupdir	origin
14/06/2011 14:44:27	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
14/06/2011 18:00:12	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
14/06/2011 19:25:04	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
15/06/2011 16:18:47	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
16/06/2011 14:29:03	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
16/06/2011 19:27:06	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
17/06/2011 17:51:25	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
17/06/2011 18:00:52	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
17/06/2011 18:14:26	Guru	guruduttmallapur.html	store.cgi	.	index.html	.	ok
17/06/2011 18:49:33	Guru	guruduttmallapur.html	store.cgi	.	index.html	.

NetworkAdmin Notes

Fri, 17 Jun 2011 13:13:54 GMT

Ebook Linux Network Administrator Guide

Internet connectivity disappears

Disconnected from Network

Check the connection icon on Taskbar
If it shows disconnect reconnect using eth0

Restart named, httpd services

/etc/init.d/httpd restart
/etc/init.d/named restart

How to find your ethernet card by making it blink!!
Linux Networking setup at LHN

Network Manager

Network Manager
Network Manager at wikipedia
NetworkManager debugging
HP Howto debug network connection loss

Bridging

Bridging at wikipedia
Subnetworks and network masking at wikipedia
CIDR or Classless Inter-Domain Routing at wikipedia
IP addressing and Subnetting for new users by Cisco
Understanding Subnetting

FireWall

iptables is built on top of netfilter, the packet alteration framework for Linux 2.4.x and 2.6.x. It is a major rewrite of its predecessor ipchains, and is used to control packet filtering, Network Address Translation (masquerading, portforwarding, transparent proxying), and special effects such as packet mangling.

Linux Firewalls with IpTables
manpage on iptables
TLDP Firewall and Proxy Server Howto
Linux Basic Firewall Configuration
Using Firestarter to Configure FC Linux Firewall
NetFilter/IpTables site

SSH

SSH notes

Telnet FTP and xinetd

Configure FTP Server
Configure Telnet, TFTP and xinetd

Apache Web Server

The Apache Web Server

NFS

Configure NFS

NIS

Configuring NIS

DNS

Querying DNS server for host-name resolution

$> nslookup www.google.com
Server:		<Your DNS Server IP>
Address:	        <Your DNS Server IP>#<Number>

Non-authoritative answer:
www.google.com	canonical name = www.l.google.com.
Name:	www.l.google.com
Address: <IP1>
Name:	www.l.google.com
Address: <IP2>
Name:	www.l.google.com
Address: <IP3>
Name:	www.l.google.com
Address: <IP4>
Name:	www.l.google.com
Address: <IP5>

DNS Troubleshooting
Dynamic DNS
DNS Quick Howto

DHCP

Configuring the DHCP Server
DHCP Quick Howto

Linux Kernel Internals

Fri, 17 Jun 2011 13:06:15 GMT

Blogs

OSDev wiki
Kernel Internals Blog by Gustavo Duartes
OSDever website for OS developers and tutorials on system internals
What Is the Kernel blog by Linux Kernel Group India (LKB_India)
Yahoo Group for Linux Kernel Group India (LKB_India)
Under the hood look at operating system internals
How to fully understand an Operating System at stackoverflow

Articles

Collection of Papers on Linux Kernel Internals
Kernel News Podcasts
Anatomy of Linux Kernel
Linux Memory in the System Performance Tuning book

KernelNewbies

Documentation at kernelnewbies
Kernel Janitors at kernelnewbies
Kernel Mentors at kernelnewbies

Silicon Valley Linux User Group (SVLUG)

Silicon Valley LUG
Reading the Linux Kernel Sources at wikiversity
Kernel Walkthrough Video 1
Kernel Walkthrough Video 2
Kernel Walkthrough Video 3
Kernel Walkthrough Video 4
Kernel Walkthrough Video 5
Kernel Walkthrough Video 6
Kernel Walkthrough Video 7
Kernel Walkthrough Video 8

Online Linux Kernel Browsable Sources

Kernel Source Browsing Tips
Step by Step Kernel hacking
Linux Kernel Sources at LXR
Linux-2.6.18 CVS Tour at tamacom

Small Linux Kernel Implementations

Learning Kernel internals with Small Linux
Lightweight Linux Kernels at wikipedia

Small Linux

The Small Linux Project
Links to other micro linuxes
Links to yet more micro linuxes

Linux Tiny

Linux Tiny at wikipedia
TinyLinux

Reference

Linux Kernel Hacker Guide
PDF Understanding the Linux Virtual Memory Manager
Linux Core Kernel Commentary 2002 2nd ed.

SysAdmin-Cmd-Ref

Fri, 17 Jun 2011 13:04:50 GMT

Running a cron job

$> vi /etc/cron.daily/
#clear apache logs at one minute past midnight (00:01) of every day of the month, of every day of the week
1 0 * * *  printf > /www/apache/logs/error_log

Cron at wikipedia

Printing full or absolute path using find command

find `pwd -P` -name <search-filename>

Note:If you give the find command an absolute path, it gives the results with an absolute path.
How can I list files with their absolute path using find

Finding large files on your harddisk

du -H . | egrep 'MB|GB' | sort -n

Extract pid or command line parameters for a program name on command prompt

$> ps aux | grep firefox | awk '{ print $2 }'      #outputs the 2nd column of the ps output 
$> ps aux | grep firefox | awk '{ print $NF }'   #outputs the last column of the ps output

Create a zip file

#Recurse through tst directory and create tst.zip
$> zip -r tst.zip tst/

Searching by file-type and containing search-string text

$> file * | grep -i python | cut -d: -f1 | xargs --replace=ABC grep -Hn <search-string> ABC

Directory listing (sorted by extension, filesize (desc) )

# -S==size, -X==extension, -r==desc-sort
$>  ls -al -S -X -r | egrep -v '.svn|.cvsignore'

Watching for file changes (creation, modification, deletion)

#watch these files every 1sec and show diff between iterations
$> watch -n1 -d "ls -al /tmp/*.log /tmp/.flag_file "

Watch command at wikipedia

Top command

$> top -b -p pid > top.log  #Capture top output for a given pid
$> top -u <username>  #Display username's process in top
$> top -p <pid-list>       #Display only given pids
$> top -n 3                   #Display top for 3 iterations
$> top -b -n 1  > top.log # Capture top output in batch mode
----
Commands available in Top display
<space-bar> - change refresh rate
M - sort by memory usage
C - sort by CPU usage (default)
O - select column to sort by any column
R - sort in reverse order of current display
W - write top settings to ~/.toprc file

k - kill task by pid
z or b - highlight running processes
c - show command line params and absolute path of processes
u - display <username's> processes only

Notes excerpted from
Useful options for Top Command in Unix
Capture Top Command output in a text file

Vim file browser

$> vim /path/to/dir/

Vim commands

p - preview a file from dir browser
Esc:Vex - split vertical and explore
'-' -  go Up to parent directory

Using vim as a file browser

View a folder structure with colors on

$> ls -R --color=always | less -R

Viewing color highlighting with less command

Search using find command

#Search for .sh files excluding a particular directory
$> find . -path <exclude-dir> -prune -o -print | egrep -i '*\.sh$'

# uses the form ( name1 OR name2 OR name3 )
$> $ find . \( -name '*.sh' -o -name '*.pl' -o -name '*.c' \) -exec egrep 'abc|def|ghi' {} \;

Find recipes
Compose your find query by entering your settings in a GUI form
find mini-tutorial
Typical errors in using find
Advanced techniques for using find command
Softpanorama collection of articles on using find, grep, xargs

Search using grep command

#Shows only text matching the search pattern (not the line containing the pattern)
$> egrep -o 'pattern' input.txt

grep mini tutorial from softpanorama

Using xargs command

xargs man page
xargs tutorial from softpanorama

Find Disk Footprint for a directory

# Display sub-totals for each sub-directory
$> du -h <dir>
# Summary of total directory
$> du -schS <dir>
# Display Free Disk Space on partitions in MB, GB
$> df --si

Mouse copy-paste on terminal

Left Button: Select text
Middle Button: Paste text
Right Button: Extend the selection

$> su -
$> yum install gpm
$> /etc/init.d/gpm start
$> /etc/init.d/gpm stop

Howto Configure Mouse copy-paste on terminal
Discussion on Best Clipboard manager for linux

Avoid no-activity timeout based logout on a terminal:

#Increase timeout based logout
$> export TMOUT=60

#Manually lock your system
$> yum install vlock
$> vlock

Timeout based logout in Linux

Searching for commands and files:

Building search databases:

$> updatedb (updates the db used by 'locate' command)
$> mandb (updates the db used by the 'man', 'whatis', 'apropos' command)
$> makewhatis (updates the db used by 'apropos' command)

Locating Useful Files and Information

$> grep <pattern> <filename>
$> find <path> -name <filename>
$> locate <filename>
$> apropos <search-term>
$> which <cmd-name>
$> man <section-number> <topic-name>

Mounted filesystems:

Statically mounted file-systems using config files:

$> vi /etc/mtab
$> vi /etc/fstab

Introduction to fstab

Dynamically Re-mounting read-only directory as read-write:

$> mount -o remount -o rw /mydirectory

Reference

Monitoring System performance with linux commands
Howto use Linux System commands at Linux101hacks
Softpanorama collection of tutorials on Unix commands

Network Debugging Notes

Fri, 17 Jun 2011 12:44:19 GMT

Netcat

A Unix Utility You Should Know About: Netcat

tcpdump

capturing info with tcpdump for use with wireshark

#capture with tcpdump for later viewing with wireshark
tcpdump -i eth0 -s 0 -w tcpdump4wireshark.cap      # -s 0 stands for capture whole packets
#tcpdump -i eth0 -s 65535 -w tcpdump4wireshark.cap

Format: tcpdump [options] [filter-expression]
Useful options

-c <count>  capture only count no. of packets
-a resolve addresses to host names
-n print numeric addresses do NOT resolve addresses to host names
-E use encryption key to decrypt packets. (use with care i.e. don't use real secret key)
-l make output line buffered - useful for       tcpdump -l | tee logfile | less
-w <logfile>  capture packets to logfile
-s <byte-count>  no. of bytes to snap a packet on. Use 0 to capture whole packets
-S dump absolute sequence numbers rather than relative sequence numbers
----
-t DON'T print time stamp in dump
-tt unformatted time stamp
-ttt prepend time delta between current and previous line in dump
-tttt prepend formatted date+timestamp on every line
----
-v
-vv
-vvv   increase verbosity in packet capture

[filter-expression]

   type: `host foo', `net 128.3', `port 20'
   dir(ection): `src foo', `dst net 128.3', `src or dst port ftp-data'
   proto: `ether src foo', `arp net 128.3', `tcp port 21', 'tcp'

tcpdump video tutorial on linux
tcpdump for dummies
tcpdump tutorial and primer
tcpdump with sample syntax and examples
Mnemonic or How To Remember Your TCP Flags
Not All SYN Packets Are Created Equal

tcpdump command manpage online
tcptrace online manual

FOSS Notes

Fri, 17 Jun 2011 12:30:44 GMT

FOSS India

CEH Notes

Fri, 17 Jun 2011 10:27:19 GMT

Training

Ksecure CEH Training

Info

CEH on Wikipedia

Wireshark Notes

Thu, 16 Jun 2011 08:58:53 GMT

PPTs

sharkfest '08 Presentations
sharkfest '09 Presentations
sharkfest '10 Presentations

Video Tutorials

Free introductory videos on wireshark
Videos downloadable from wireshark docs
Training Materials for Wireshark university
Video/PDF WSU01 - Wireshark Functionality and Fundamentals
Video/PDF WSU02 - Wireshark TCP/IP Network Analysis
Laura's Wireshark Jumpstart Material

Install Wireshark

To enable packet capture without root permission follow instructions in these 2 blogs

#Fedora
#Already installed wireshark, just need to enable packet-capture without needing to run wireshark as root
$> su -
$> yum install bison flex gtk2-devel libpcap-devel c-ares-devel libsmi-devel gnutls-devel libgcrypt-devel krb5-devel GeoIP-devel

#Find dumpcap to enable packet capture for this program
$> locate dumpcap
/usr/sbin/dumpcap

#set capabilities to enable packet capture for non-root users
$> setcap 'CAP_NET_RAW+eip CAP_NET_ADMIN+eip' /usr/sbin/dumpcap        

$> ldconfig         #Refreshes the shared library cache with updated libraries

Step-wise instructions for Fedora and Ubuntu: Compile and Install Wireshark on Fedora and Ubuntu by Marc Weisel
Steps and explantion of steps: Enabling Wireshark Packet Capture as Non-Root user by Jeremy Stretch at packetlife
Step-by-step instructions and explanation: Packet Capture Priviledges at wireshark wiki

Network Trouble-shooting Newbie Howtos

Wireshark wiki at wikipedia
New to Network Troubleshooting at wikishark wiki
Network Troubleshooting at wikishark wiki
Principles of network troubleshooting
3Com's Network Troubleshooting Overview
Cisco's Internetwork Troubleshooting Handbook
Cisco's Overview section provides a good general problem-solving model

Wireshark Newbie Howtos

Capture setup at wireshark wiki
Capture setup for Ethernet at wireshark wiki

Installation

# install the gui and command line commands for wireshark
$> yum install wireshark-gnome wireshark

Capture server-side packets and view on client side using tethereal

[server ]$> tethereal -f "tcp port not ssh" -w /tmp/tethereal/server-eth.cap
Capturing on eth0
986 
[server ]$> chmod 777 /tmp/tethereal/server-eth.cap
[server ]$> scp server:/tmp/tethereal/eth.cap client:/home/user/Desktop/tethereal/server-eth.cap
[client ]$> wireshark server-eth.cap &  #view the server side capture on any client machine

Customizing Wireshark

Using conversations to drill down to what you want ( Statistics > Conversations )
Display filters at wireshark wiki

$> locate dfilters
/root/.wireshark/dfilters
/usr/share/wireshark/dfilters

Coloring rules at wireshark wiki

Reassembly of TCP segments

Wireshark displays packet with Info: ..TCP segment of a reassembled PDU
TCP_Reassembly at wiki.wireshark
TCP packet Info: Reassembled PDU in wireshark

The message means that TCP handed off the dissection to a higher layer protocol dissector (like HTTP dissector)
This dissector told the TCP dissector to collect multiple TCP segment to construct one PDU. 
If all goes well, the packet that contains the last part of the application PDU will have full dissection
of the application protocol. If this does not happen, please file a bug on http://bugs.wireshark.org and
attach the capture file of that particular tcp session.
You can disable the reassembly of TCP segments by un-checking the 
"Allow subdissector to desegment TCP streams" in the TCP protocol preferences. 
That way, all parts of the application PDU will be displayed on their own.

Note: Need to enable HTTP Reassembly in addition to TCP Reassembly using

Edit->Preferences->Protocol->TCP->"Allow subdissector to desegment TCP streams"
Edit->Preferences->Protocol->HTTP->Reassemble header/bodies/chunked transfers across multiple TCP segments

TCP and HTTP Relative Sequence Numbers

Understanding TCP Sequence and ACK numbers in wireshark
Web Proxy Sends TCP Reset Instead of Only Closing Session at MS-kb
Turn on/off TCP Relative Sequence Numbering

Edit->Preferences->Protocols->TCP->Relative sequence numbers and window scaling

Control what and how much you capture with Capture filters at wireshark wiki
tcpdump settings are common with other pcap based analyzers tcpdump manual page
tcpdump and wireshark cheat sheets (pdf)

Export downloaded GIF, JPEG, PDF files from Wireshark Trace/Dump

Select JPEG 200 OK packet
Select JPEG from middle pane
Right click->Export Selected Bytes

Howto export JPEG file from wireshark

Tools and Utilities to extend/complement WireShark

Tools for working with wireshark and tshark at wiki

Reference

Wireshark User Guide
Ethereal website
Ethereal FAQ
Ethereal Docs
Ethereal wiki

Wireshark HTTP protocol reference wiki
Wireshark Protocol Reference wiki
wireshark and tools command line man-pages
Wireshark documentation
Wireshark bibliography and articles
Laura Chapell's booklist
Wireshark display filter reference
libpcap wiki at wikipedia

Remote Desktop Notes

Thu, 16 Jun 2011 07:44:23 GMT

Connecting over intermediate machine

$> ssh -X <intermediate-machine-ip>
$> rdesktop -g 97% <remote-machine> -u <username>

Switching windows in remote machine

 ctrl+alt+tab

XSL Notes

Wed, 15 Jun 2011 11:08:10 GMT

xsltproc

$> xsltproc --verbose --debug tst.xsl tst.xml

$> man xsltproc 
--verbose or -v: show logs of what's happening
--timing: display the time used
--debug: dump the tree of the result instead
--stringparam name value : pass a (parameter, UTF8 string value) pair
--dumpextensions: dump the registered extension elements and functions to stdout

Finding relatives using xslt
Test if descendant node exists
How to find if current node is ancestor or descendant of a particular node
How to remove duplicate xml nodes using xslt
FAQ on XSLT Grouping
Multi Pass XSLT by Uche
Multi Stage XSLT

Tutorials

XSL tutorial at w3schools
XSLT examples at w3schools
XSLT and XPATH tutorial at xmlmaster.org

Exslt

Exslt website for extensions to XSL
Howto use Exslt at exslt.org
exslt func:function docs

Excerpted Notes on some commonly used xsl functions

The xsl:template mode attribute

Both xsl:template and xsl:apply-templates have an optional mode attribute. 
If xsl:template does not have a match attribute, it must not have a mode attribute. 
If an xsl:apply-templates element has a mode attribute, then it applies only to those template rules from xsl:template elements that have a mode attribute with the same value; 
if an xsl:apply-templates element does not have a mode attribute, then it applies only to those template rules from xsl:template elements that do not have a mode attribute.

xsl:copy element

The <xsl:copy> element creates a copy of the current node. 
Note: Namespace nodes of the current node are automatically copied as well, but child nodes and attributes of the current node are not automatically copied!

xsl:copy-of element

The <xsl:copy-of> element creates a copy of the current node.
Note: Namespace nodes, child nodes, and attributes of the current node are automatically copied as well!
Tip: This element can be used to insert multiple copies of the same node into different places in the output.

Debugging

XSLT debugger at sourceforge
xsldb sample debugging session
KXSLDbg
KXSLDbg Handbook
How to debug XSLT on the fly Uche Ogbuji

Reference

XSLT Element Reference at w3schools
XSLT Function Reference at w3schools
XPATH, XQUERY and XSLT 2.0 Functions Reference at w3schools.com
Introduction to XSLT with simple examples
XSL FAQ
Book review of XSLT 2nd Ed. Doug Tidwell

GNOME XSLT References

Library Internals for XSLT C Library for GNOME
XSLT FAQ
xsltproc tool options
xsltproc man page

libxslt

libxslt tutorial
libxslt API

Bash Scripting Notes

Wed, 15 Jun 2011 10:08:55 GMT

Bash Options

#Display current options
$> set -o
#Change options
$> set -o noclobber           #don't allow overwriting of existing files
$> touch existing-file
$> set +o noclobber

$> set -o noglob               # don't do file expansion for '*', '?' etc.
$> set +o noglob              # revert to file expansion default option

Bash options from Bash Beginners Guide

Bash Scripting

Shell Variables

Print Global variables

$> env
$> printenv

Script Command line parameters

$0       #scriptname with full path
$1       #first parameter to script
$#       #last parameter
${#@}     #No. of parameters to script

Print current shell variables

$> set
$> set VARNAME=VALUE

Make a local shell variables into global environment variables

$> export VARNAME=VALUE

Command line parameters to a shell script

$@ #space seperated script parameters (starting from one)
$*  #similar to $@ ( deprecated )
$#   #count of command line parameters to shell script
$?   # return value of any sub-script or command
`basename $0`  # returns script name minus the absolute path

Bash Special Script Parameters
Bash Variables - Normal, Reserved and Special ones

Shell Expansion

Command Substitution

$(ls -al)
or
`ls -al`

Parameter Expansion

${VARNAME}

Process Substitution

cat <(process)           #Note no space between <(
or
ls  >(process)           #Note no space between >(

Different Types of Shell Expansion

Sourcing a script file into current execution context i.e. another script file or in current shell

#Within a script file
. /path/script-file    (OR)
source /path/script-file
----
#At the bash prompt
$> .   /path/script-file  (OR)
$> source /path/script-file

Conditional Operators (if-else)

Using the ... test construct, rather than [ ... ] can prevent many logic errors in scripts. For example, the &&, ||, <, and > operators work within a test, despite giving an error within a [ ] construct.

TODO

Bash Test Condition Constructs if-else

Bash File Test Operator

TODO

Bash File Test Operators

Operations on Variables

Variable creation and initialization

${VAR:-init-string}
${MYVAR:-hello}         # if MYVAR is undefined or null MYVAR='hello' else MYVAR=$MYVAR

Variable initialization

${VAR:=init-string}
${MYVAR:=hello}       #

string-length

${#VAR}            #Returns no. of string-length

substring

${VAR:OFFSET:LENGTH}

${VAR#word}              #Delete shortest match of <word> in variable's value
${VAR##word}            #Delete longest match of <word> in variable's value
----
${VAR%word}              #Delete shortest match of <word> in variable's value starting from string-end
${VAR%%word}           #Delete longest match of <word> in variable's value starting from string-end
----
${VAR/pattern/subst}              #Replace first match of pattern with substitution string
${VAR//pattern/subst}              #Replace ALL matches of pattern with substitution string

Transformations on Shell Variables from Bash Beginner's Guide

Shell Commands

initilog

More info: man initilog
reads /etc/initlog.conf settings file
-c/--cmd=command   # command to run and redirect its output to syslog files
-e/--event=1,2,3,4     #passed,failed,user-interrupt,failed-dependancy
-n/--name=<string>     # prepend <string> to the logged lines e.g. "inetd"
-q                  #quiet unless command returns non-zero return value i.e. [ $? != 0 ]
--run=program  #execute program with open file descriptor for program to send back commands to initlog
--conf=file        #specify alternate config file

See also: syslog(3) and logger(1)

env - run a command in an environment or display current global environment

$> env -i VAR1=VALUE VARN=VALUE <command> <params>
$> env

pidof

$> man pidof
$> pidof <options> program [program...]
-s       #display only single pid for given name
-x       #display even 
-o <pid>      #exclude given pid from listing - ex: %PPID (parent pid)

Bash Programming Introduction Howto at tldp.org
Bash Guide for Beginners at tldp.org
Advanced Bash Scripting Guide at tldp.org
Greg's Bash Guide

Discussion on good books on bash with good links
Heiner's SHELLdorado (also see links section)
Linuxguru's shell scrip resources
Bash shell scripts directory for Linux, FreeBSD, Solaris, UNIX
dotfiles.org
Wicked Cool Shell Scripts
Shellscripts.org
NixCraft
UNIX shell scripting
Scroogle "shell scripting" tutorials

Debugging

   $> script -f -q <logfile>
   $> ./myscript.sh
   ^D

Capturing all Input and Output to a script

Debugging entire script

   $> bash -n -x -v script.sh       # syntax-check, trace, verbose (print input lines)
   (OR)
   #!/bin/bash -nxv                    # Add this line at the first line of script

Debugging parts of script

 set -x          #activate tracing
 ....
 set +x         #DE-activate tracing

 set -f          #Disable filename globbing
  ...
 set +f          #Activate filename generation with globbing

Debugging Script Location

$> export PS4='+${BASH_SOURCE}:${LINENO}:${FUNCNAME[0]}: '
$> bash -n -x -v script.sh

Debugging with echo and tee

  echo $suspect_variable
  cat abc.txt | tee input.txt | process.sh | tee output.txt | less

Tracing variable after every command

# Echoes the value of $variable after every command using DEBUG
trap 'echo "VARIABLE-TRACE> \$variable = \"$variable\""' DEBUG

#Dumping variable info on EXIT
trap 'echo Variable Listing --- a = $a  b = $b' EXIT

Note: Bash options are a bit counterintuitive

-x     (activates tracing)
+x    (deactivates tracing)

How to run a Test Suite using a bash script

#!/bin/bash
# Run tests on all xml files and show diff between input and output

for file in $(ls xml/*.xml); do
    echo "Processing file: $file"
    ./my_filter.py < $file | xmllint --format - > "$file.out"
    xmllint --format $file > $file.in
    diff "$file.in" "$file.out"                   #TODO: Need to add logic for testing pass or fail
    #rm -f "$file.in" "$file.out"
    echo "=========================="
    read    #enter something to move to next testcase
done

for f in /etc/*           
do
   echo ${f}
done

for-loop at Bash Beginner's Guide

exec vs eval in bash scripting
How to use exec bash command properly
Howto make bash print every command before execution at stackoverflow
Discussion on How to debug a bash script at stackoverflow
How to debug bash scripts
Bash hackers debugging tips
Bash Scripting Gotchas
Bash PitFalls
Basics of Debugging Bash Scripts
Advanced Debugging of Bash Scripts
Bash Debugger at sourceforge

JavaScript Notes

Tue, 14 Jun 2011 12:30:07 GMT

Javascript

Video Tutorials

UPE Workshop #1: JavaScript 101 - 1hr Video from Google
JavaScript - The Good Parts - 1hr Video from Google
Upcoming changes to the Javascript Language
Best Practises in JavaScript Library Design from google
Introduction to JavaScript and Browser DOM - 1hr Video from Google
TechTalkies Videos on Javascript
1hr Video Tutorial on Javascript (1/3) from IIT Kharagpur

Help I don't know Javascript CSS HTML

Presentations

Doug Crockford - JavaScript : The Good Parts Presentation
Blog on JavaScript : The Good Parts

Addons

Dynamic JavaScript Deobfuscator Addon for Firefox

Books

Javascript - The Good Parts by Doug Crockford
Javascript : The Definitive Guide by David Flanagan
Javascript Cookbook by Shelley Powers
Javascript Patterns book by Stoyan Stefanov

Php

UPE Workshop #4: Server-Side Technologies (PHP) - 50 Min Video from Google

Distributed Development

Tue, 14 Jun 2011 12:29:00 GMT

Distributed Collaboration Tools

Essentially the problem with distributed teams is how to keep the communication going when people work on

different locations
times
project modules
viewpoints

The following points need to be built into the shared environment

encourage communication - shared purpose, belonging to the community, recognition within the team.
co-ordinate communication - chat room with searchable history by whole team to avoid repetition of discussion.
capture asynchronous communication - people availability is at different times
ease-of-use - use tools to reduce mental overhead of doing above activities

Tools to help tune communication needs and reduce communication overhead.

Web Hosting

Comparison of FOSS hosting sites at wikipedia

Hosting FOSS comparison
Open Source Project Setup
What Open Source Hosting should I use

Version Control

Getting Started with Open Source - Stackoverflow discussions

Seeking advice for OpenSource project
How to go open source and get community support
How to get users to your open source project
How to promote your open source project
How to get contributors to your open source project
Howto for an Open Source Newbie
Best way to get into an Open Source Project
Get started on Open Source Projects with OpenHatch
Howto get started code reading open source projects like firefox
What level of programming should I have to contribute to open source
How to contribute code back to Open Source Project
Open source projects that are easy to contribute (code) to
RedHat - How to get your code into an open source project
How did you start with open source projects
How to find open source projects which require your skills
How to get support for a new Open Source Project
Motivation for developers on Open Source Project
Advice on Starting an Open Source Project

Publicizing your project

Slashdot
Freshmeat
Twitter

Why Seeing is Believing !!

Video Tutorials - A video is worth a million Words. Don't tell me how Just show me!! We've evolved in an audio-visual world where confusing scenes are understood in a real time holistic way. Imagine a lion trying to hunt by step-by-step GPS directions!! Like lions We're very good Copy Cats. Including tags and textual video transcripts makes for easy searching.
Video Conferencing - Commitment and Trust are intrinsically tangled. We've got built-in BS filters which have evolved to read faces, voices and body-language all at once. Any mismatch is immediately picked up. See the TV Series LieToMe for dramatized enactment.
1. Skype
Whiteboard - A Picture is Worth a Thousand Words.
1. Digital Pen,
2. MS NetMeeting
MindMap - Visualizing and organizing ideas.
Screen Sharing (VNC) - First hand experience is better than second hand reports.

Healthy Grapevines make for Sweet Grapes

FAQ: "Faq-O-Matic is a CGI-based system that automates the process of maintaining a FAQ (or Frequently Asked Questions list). It allows visitors to your FAQ to take part in keeping it up-to-date. A permission system also makes it useful as a help-desk application, bug-tracking database, or documentation system."
Wiki : Wikis do 2 things really well
1. "Give them muddy raindrops and they'll give you pools of cool waters"
2. They help clean, sift and weave together stray comments into dependable references (Wikipedia... need I say more).
3. TWiki
4. TiddlyWiki
5. WikiMania - hosting site for collaborative wiki
6. Swik.net - hosting site for open source project wikis
  1. SWik main page
  2. Getting Started with SWik
IRC (with logging and global search) - Ask the guy who comes to office wearing a plaster cast. Pretty soon it gets very tiring explaining what happened to the Nth person you meet. Imagine if that happened every day for years. Enough to make you wear sign-boards round your neck. Chats texts mimic conversations but allow for recording, refinement and reuse.
MailingLists (MailMan)
1. Remote Pair Programming - Like a spider web with a struggling fly and a hungry spider - Local actions have global impact and Global actions have local consequences. Pair Programming helps couple the immediacy of writing software with the awareness of the depth and width of the software.
2. Eclipse Plugins
Code Review tools - CodeStriker,

Specialized tools reduce incidental overhead

IDEs - You concentrate on your work and let the IDE take care of adapting the different tools to suit your needs. This reduces the context-switching overhead when using different tools each with its own set of options, quirks and idiosyncracies.

Distributed Development Team

Video tutorials

Video on Agile Distributed Team
UPE Workshop #3: Open-source development best practices - 1hr Video from Google
Learning from Stackoverflow.com - 50 Min Video from Google

Karl Fogel is one of the maintainers for the Open Source Version Control software Subversion (SVN for short).
He shares his experience with Open Source in his online free book "Producing Open Source Software"
Also Check out the video's at the bottom of the page.
Karl Fogel's online book on Producing Open Source Software
Video - How Open Source Projects Survive Poisonous People (And You Can Too)
Video - Principles of Participation for Open-Information Communities by Karl Fogel at Google Talk
Podcast on distributed development by Ben and Fiz

Articles

Free and Open Source Project Management Howto at tldp
Virtual Team on wikipedia
Tools for Geographically Distributed Development Teams (GDD)
Open source Tools for Distributed Development
PDF on Workplace e-collaboration
GDD related articles

References

Debugging Notes

Mon, 13 Jun 2011 11:05:29 GMT

Watching Files for changes (creation, modification, deletion)

#watch these files every 1sec and show diff between iterations
watch -n1 --differences=cumulative "ls -al /home/self/changing-file.txt /etc/abc.conf"

Watch command at wikipedia

Finding Open Files with lsof

IBMdeveloperworks article on using lsof for debugging your application
A Unix Utility You Should Know About: lsof
The Power of lsof
Leveraging lsof to debug network applications
lsof FAQ
lsof manpage

Tracing system calls with strace

strace at wikipedia
strace man page
strace at sourceforge
Fun with strace and gdb
Debugging with strace at redhat
Debugging web-apps with strace
Debugging applications with strace at debian-admin
strace introduction article at linuxplanet
strace blog post
5 ways to troubleshoot using strace
strace power troubleshoot at linuxhelp
code your own strace

Excerpts from strace manpage

$> strace -t -f -ff -ostrace.program  /path/to/program

$> man strace      #NOTE: no space between option and value below
-c count time, calls, and errors for each system call in summary report
-S <sortby> time|calls|name|nothing
-o <logfile> write output to filename
-ff  create logfile.pid for each subprocess (used with -o)
-f follow child processess across fork()s
-v verbose unabbreviated display for env-variables, stat, etc. (all the gory details)
-p <pid> attach to pid (can use multiple -p p1 -p p2 -p pN)          #Ctrl-C to stop tracing
-s strsize  max string size to display (default is 32)
--
-e expr  # [qualifier =][!]value1[,value2, ...]   
            # where qualifier=trace|abbrev|verbose|raw|signal|read|write
            # and value depends on qualifier

-e trace=all|none|file|process|network|signal|ipc
--
-t prefix each line with time of day
-tt prefix each line with time of day with microseconds
-ttt prefix each line with time from epoch in microseconds
-r relative timestamp

Tracing libary calls with ltrace

Very similar to strace command except that it lets you watch library calls in addition to system calls.

$> ltrace -s100 -p 1234 -dd > ltrace.txt
$> vi ltrace.txt              #Search for libary calls like strncmp(), strncat(), malloc(), free() in addition to system calls

Has many options very similar to strace
-p <pid> #attach to pid and trace
-S          #trace system calls in addition to library calls
-n<num> #indent nested calls by num spaces
-d[dd]   #debugging output more d's for more verbose output
-s num  #max string length to display
-C         #demangle C++ names

Reverse engineering

Peeking inside an application
Disassembling your application to understand it

HTTP notes

Mon, 13 Jun 2011 09:57:00 GMT

Http : The Definitive Guide by David Gourley and Brian Totty
HTTP wiki at wikipedia
List of HTTP Status/Error Codes at wikipedia
List of HTTP Headers
List of HTTP Header Fields at wikipedia

Content-Length

HTTP Content Length in RFC2616
Message Length (Restrictions on Content Length) in RFC2616
Extra bytes at end of download (search for Content-Disposition)

Transfer Encoding

Transfer Encoding in RFC2616
Transfer Encoding Types in RFC2616
Chunked Transfer Encoding at wikipedia
Chunked Transfer in RFC 2616

Content-Type

Content-Type or MIME Type
RFC 2046 MIME Types

Content-Disposition

RFC 2183 on Security issues with using Content-Disposition HTTP Header Field

Persistent Session

HTTP Persistent Connection at wikipedia
HTTP Persistent Connections in RFC 2616
HTTP Pipelining of Requests at wikipedia
HTTP Cookie at wikipedia
Cross Site Scripting at wikipedia
Keep Alive Notes by Roy Felding
Configuring Firefox Keep Alive for Persistent Connnections
Configuration Mania for Firefox
1998 article on Persistence support in different browsers

Proxy Servers

Proxy Server at wikipedia
Web Cache at wikipedia
Cache Validation with Etag at wikipedia
Gateway at wikipedia
Origin Server or Upstream Server at wikipedia
Firewall at wikipedia

HTTP State Transitions

HTTP Sequence diagram (pdf) at eventhelix-realmantra
HTTP Made Easy by JMarshall
TCP/IP and application protocols sequence diagrams (pdf) at eventhelix

Capture content on the wire using ngrep

$> ngrep -Wbyline -dlo port 3000
$> ngrep -Wbyline google port 80

Wrong content-length
ngrep basic usage
ngrep usage article on linux.com

Debugging

nc or netcat
socat
ngrep
fiddler
wireshark
tcpdump

tcpflow -cvs | httpflow.py

TCPWatch (Python)
Tamperdata
latest version of http-twiddle

Telnet

[gmallapu@guru-linuxdev ~]$ telnet www.google.com 80
Trying 74.125.127.105...
Connected to www.google.com.
Escape character is '^]'.
GET / HTTP/1.1
host: www.google.com

HTTP/1.1 200 OK
Date: Fri, 15 Apr 2011 13:00:16 GMT
Expires: -1
Cache-Control: private, max-age=0
Content-Type: text/html; charset=ISO-8859-1
Set-Cookie: PREF=ID=4b510bfa6bac31fa:FF=0:TM=1302872416:LM=1302872416:S=PrxMK3mgFt4eca4P; expires=Sun, 14-Apr-2013 13:00:16 GMT; path=/; domain=.google.com
Set-Cookie: NID=46=WXdAeNXkS0rRGrYBdgxDZJj7ZLKw6mVVFgbr9PwyVhSUK2UrV6jfLthlXQeT-oF2rGEgbhhbH6NiiLrOtqlu_aHc_Fl5L0of_ln50gIFSxV5Q09ieCE1eDxu6OnyH09k; expires=Sat, 15-Oct-2011 13:00:16 GMT; path=/; domain=.google.com; HttpOnly
Server: gws
X-XSS-Protection: 1; mode=block
Transfer-Encoding: chunked

1000
[...]

Simulating web conversation POST with PHP and curl
Http Header debugging with telnet and other tools
Best Viewed with telnet to port 80
TroubleShooting HTTP using Telnet

Reference

RFC

HTTP RFC 1945 (informational)
PDF of HTTP RFC 1945 (informational)
HTTP RFC 2616 (standard)
PDF of HTTP RFC 2616 (standard)

Linux Embedded Notes

Wed, 08 Jun 2011 09:38:00 GMT

Embedded Linux Free Training Material at Free Electrons
MicroC OS II: The Real Time Kernel by Jean Labrosse
Introduction to RTOS

Minix3

Minix3 website
Minix3 FAQ
Minix3 Wiki
Minix3 Doc
Minix 3 - Operating System Design and Implementation

Networking Internals

Wed, 08 Jun 2011 08:50:00 GMT

Books

TODO

Tiny TCP/IP Stack

uIP - tiny Linux networking implementation
Download uIP Source Code

Swimming Notes

Tue, 07 Jun 2011 13:01:00 GMT

Started learning swimming recently.

Blog

I've started a

Swimming Notes blog and
this wiki: http://guruduttmallapur.tiddlyspot.com/#[[Swimming%20Notes]] on it.

The blog is basically a journal on what I learn each day. I may also update it with articles later.

Found some really good training videos And a book. The videos are available on-line.
So learning from local coach as well as trying out the self-learning.

Total Immersion

It's amazing how easy this guy (Terry Laughlin of Total Immersion) makes it.
All you need to do is understand the basic principles and how to apply them.
This allows you to quickly find out your own mistakes and correct them.
You need to spend very less amount of energy.
Kind of like the fish, except they've evolved for water and we've not... so we need to compensate.
But once you learn that technique swimming becomes so much fun.
You can swim quite fast without tiring or having to be an athlete.
It's kind of like ice-skating.

Technique

But most people learn it the wrong way and end up exhausting themselves so much that it stops being fun.
Well water is 700 to 1000 times denser than air.
On top if you use the wrong technique and weakest muscles to do the work it's even worse.
The old technique involves fighting with the water (human swimming) vs cooperating with water (fish-like swimming)
Leg muscles are the strongest yet swimmers routinely learn to speed up their arm muscles.
It's like trying to walk on your hands.... possible but not as good as walking on your legs.

Principles

Basically when you're in water the most important thing is not to increase speed but reduce drag.
The equivalent of air-resistance for cars/rockets.

Videos

Total Immersion (Video) store
"total immersion learn swimming techniques" at youtube
Videos on Total Immersion

Presentation Slides

Videos - "Total Immersion presentation slides" at youtube

Textual Info

Free PDF download at Total Immersion
rec.sport.triathlon FAQ on Total Immersion
Wiki on Terry Laughlin's Total Immersion Technique at wikipedia
Swimming wiki at wikipedia
Concise Physics of Swimming by Tara Koff
Book - Total Immersion by Terry Laughlin at flipkart
Physics of Swimming Dolphins at Discover Magazine
My Swimming Notes Blog

Python Notes

Tue, 07 Jun 2011 08:31:00 GMT

Installing Python Modules (using distutils)

Download the archive file
Unzip it
cd to the the unzipped folder
python setup.py build
python setup.py install

Installing and distributing python modules
Tutorial on Distributing Python Modules at pythonware

Basics

Python Tutorial at docs.python
Brief Tour of the Python Standard Library
Commonly used syntax of python Learn Python in 10 Minutes Tutorial
Dive Into Python online pdf
Dive Into Python 3 : Dissecting a Python program
Beginners Guide to Python
Python 101 : Introduction to Python
Building Skills in Python (for programmers)
Instant Python Tutorial
Python Algorithms
Learning Python - My Collection of Resources and Links
Python Language overview Python Syntax and Semantics at wikipedia

Indentation in Python

Python IDLE IDE
a) Use Format menu

a) (Un)Indent Region
b) (Un)Tabify Region
c) Strip trailing Whitespace

b) Use Edit menu

  Preferences menu item to set tab-width to 4 spaces

c) Don't intermix vim and IDLE unless you match the tab/space settings equally in both as below:
indent aka python.vim Vim script
python omnicomplete (intellisense) Vim script
pydoc plugin for Vim
python code folding plugin for Vim
Code browsing and auto completion in Vim Python

Vim PythonInfo wiki by moin
Python Code Completion script for Vim
Customizing Vim as Python IDE
Indenting Python with Vim
Vim Settings for Python
How to setup Vim correctly for Python at stackoverflow
Myths about indentation

Types

Built-in Types in Python at docs.python

Strings

Python Tutorial - Introduction to Python strings
Python string methods
Python string formatting operations like sprintf()
Python string.format() (ver 2.6 onwards)

Common problems (FAQ)

Q) I get an exception like so : "TypeError: not all arguments converted during string formatting"
A) Count the no. of % symbols vs no. of tuple members parameters of string formatting

Control-Flow ( if/else, for, while loops, break, continue )

if , for, while, try, with, functions, class definitions
main() or __main__ in python
Control-flow statements in Python Tutorial

lambda functions

def indentXML() :
    #Let indentString variable refer to the anonymous lambda function object
    indentString = lambda level: "    "  * level             #uses string's * repetition operator 
...
    curLevel++
    #indent xml info
    print indentString(curLevel) + node.getInfo()       #get unindented xml string and add indent level

Here it looks like a function call but actually expands to an inline insertion of the lambda expression.
lamdba function usage in Dive Into Python
string repetition using '*' string operator in Python

Error and Exception handling

Built-in Standard Library Exceptions
Error and Exception Handling in Python Tutorial
Exceptions are Classes Too in Python Tutorial

Data-Structures

Set

Set Tutorial

Dictionary

Dictionary at docs.python
case-insensitive dictionary

>>> d = { 'a' : 1, 'b' : 2, 'c':3 }
>>> d
{'a': 1, 'c': 3, 'b': 2}
>>> d.keys()
['a', 'c', 'b']
>>> d.values()
[1, 3, 2]
>>> 'a' in d
True
>>> d['x'] = 24
>>> d
{'a': 1, 'x': 24, 'c': 3, 'b': 2}
>>> 'x' in d
True
>>> d['z'] = 26
>>> d
{'a': 1, 'x': 24, 'c': 3, 'b': 2, 'z': 26}
>>> del d['z']
>>> d
{'a': 1, 'x': 24, 'c': 3, 'b': 2}
>>> d['phonelist'] = [ 1, 2, 3, 4, 5 ]
>>> d
{'a': 1, 'x': 24, 'c': 3, 'b': 2, 'phonelist': [1, 2, 3, 4, 5]}
>>> d['phonelist']
[1, 2, 3, 4, 5]
>>> d['PHONELIST'] = [ 2, 3, 4, 5, ]
>>> d
{'a': 1, 'c': 3, 'b': 2, 'phonelist': [1, 2, 3, 4, 5], 'x': 24, 'PHONELIST': [2, 3, 4, 5]}
>>> for key, value in d.iteritems():
	print "Key:", key, "Value:", value

Key: a Value: 1
Key: c Value: 3
Key: b Value: 2
Key: phonelist Value: [1, 2, 3, 4, 5]
Key: x Value: 24
Key: PHONELIST Value: [2, 3, 4, 5]

Stack

Using Lists as Stacks in python

Classes

Classes in Python at docs.python
A first look at classes in python at docs.python

Debugging

How to source/reload when using 'python -i'
Interactive Debugging in Python
pdb documentation at docs.python
pdb debugger commands
Blog notes on using pdb
Lint for Python [[ Pychecker (lint for python)
pydb website
Howto Python Debugging with GDB (ver 7.1)

Command-line options

argparse API Reference
optparse API Reference
getopt for python API reference

Logger library

logging.Logger - Basic Tutorial
logging.Logger - Advanced Tutorial
logging.Logger - Cookbook
logging.Logger - API Reference

Profilers

Python Performance Tips
The Python Profilers at docs.python
Psyco JIT optimizing bytecode compiler
PyInline - embed C source code into your Python script

C Shared Libraries

ctypes Tutorial - shared library support in python
ctypes API Reference

Python and XML

Python HTML and XML markup packages
Basic Python and libxml usage
Howto escape xml single, double quotes, <, > symbols in Python

PyXML (abandoned project OR absorbed into Python standard library)

PyXML Tutorials and Documentation
PyXML FAQ on Python XML libraries

libxml2

Python libxml2 small example
Python libxml2 API reference
Using libxml in Python
Config file processing with libxml2 and PERL
libxml python bindings webpage
C libxml2 tutorial
XmlTextReader: Dom/SAX hybrid with cursor facility for need based reading of xml:
LibXML2 XmlTextReader Tutorial for C and Python

SAX

Parsing XML with SAX in Python simple example
xml.sax.handler in python
xml.sax.reader in python
xml.sax Attributes interface in python
xml.sax in python
Howto set the encoding for SAX parser in python
SAX project in java with examples and documentation
SAX Incremental Parser usage example with feed(), close()
—
Handling Huge CSV and XML files in Python
Python xml.elementree handle very large xml file at stackoverflow
SAX2DOM chunker for huge XML files
Building Dictionaries with SAX uses PyXML

xml.etree.cElementTree

Parsing large xml file in Python with source example
Howto parse large xml files in python
xml.cElementTree parse on demand and free after usage is complete
xml.cElementTree incremental parsing with iterparse()
cElementTree API for low memory usage xml parsing

xml.etree.ElementTree (standard library) (slurps entire parsed doc into memory use xml.etree.cElementTree instead or libxml2)

Blog on Learning XML parsing using python's xml.etree
xml.etree article (2003)
xml.etree at docs.python
xml.etree at effbot website
xml.etree website
xpath support and limitations in xml.etree
missing support for processing instructions/comments above the root element in xml.etree

lxml.etree (external implmentation of etree)

High-performance XML parsing in Python with lxml
howto use event-driven parsing of iterparse() from the lxml tutorial
iterparse() of lxml tutorial
lxml incremental parsing (non-blocking)
sax support in lxml
lxml tutorial
lxml website

minidom (very resource hungry only usable for small files)

Minidom tutorial at wiki.python
minidom at docs.python
Processing XML in Python Using 'minidom' ( Chapter 5 of Dive Into Python)
Filtering values in xml using minidom
Finding node and its parent using minidom

OS interface

system() command

 text_file = "./abc.txt"
 os.system("cat " + text_file )

Common os.path operations in Python
Tour of Python standard library: The OS interface
Python's 'os' module for individual file commands

Filesystem

PDF - Python Tutorial on File and Directory access
Python docs on File and Directory Access
Python's shutil module for high-level file collection commands

Pipes

 os.popen("cat " + text_file ).read()

 #Code to grep for 'main()' in strCode and set flag foundMain
 foundMain = os.popen("cat -  | grep 'main()' | wc -l ", "w").write( strCode ).read()

Using os.popen at docs.python
Backticks operator equivalent in python

Unicode and UTF-8

PDF Presentation Slides Unicode-EPC2002-Talk
Chapter 9 on Unicode of Dive Into Python
How to Use UTF-8 with Python
Python Unicode Objects by effbot
Joel Spolsky on Unicode and Character Sets (No Excuses!)
Unicode HOWTO — Python v2.7.1 documentation
XML.com: Proper XML Output in Python
XML.com: Unicode Secrets
Unicode In Python, Completely Demystified
Unicode HOWTO — Python v2.7.1 documentation
Unicode website

UTF-8

UTF-8 History
UTF-8 website
UTF-8 RFC 3629

iconv

iconv based unicode converter
iconv utility to convert between character-set encodings
libiconv library to convert between character-set encodings

PEP 8 -- Style Guide for Python Code
PEP 100 -- Python Unicode Integration
Unicode at fileformat

Reference

The Python Tutorial
Python FAQ
The Python Language Reference
Python Standard Library (API Reference) at docs.python
Search for libraries at Python Package Index
Python Browsable LXR Source code tree (ver3.1.2, ver2.6.5, ver2.5.4)

C++ Boost Notes

Tue, 07 Jun 2011 07:00:00 GMT

boost::noncopyable

boost::noncopyable utility mix-in class
NonCopyable Mixin at C++ Idioms wikibook
Deriving from boost::noncopyable doesn't count as derivation but more like an assert

boost::type_traits

boost::type_traits tutorial

boost::bind()

Used to create a functor by binding params to a functions signature
Its much better than the C++ STL adapter functions bind1st() and bind2nd().
You can
a) bind any number of parameters for a given function (not limited to unary/binary functions).
b) bind member function parameters
c) bind function pointers
d) bind function objects
You can also use boost::ref() and boost::cref() to bind to a function object reference.

boost::bind() tutorials

How does boost::bind work (internals) at Ravi Honnavalli's blog
Clear and simple blog on boost::bind usage with examples
Discussion on summing a vector using boost::bind
Summing a vector
boost::bind 1.44 docs
boost::bind 1.45 docs