Eikonal Blog


Genetic diversity of humans

Filed under: past — Tags: , , , , , — sandokan65 @ 13:04

Code analysis, Debugging and reverse engineering / Code security




Malware analysis

Filed under: antimalware, infosec, security testing — Tags: , — sandokan65 @ 11:33

Personal computer security

Anti-mallware (=Antivirus)




Anti-Rootkit / Rootkit detection

  • Trend Micro’s RootkitBuster – http://free.antivirus.com/rootkit-buster/
      A rootkit scanner that offers ability to scan for hidden files, registry entries, processes, drivers and hooked system services, and MBR. It also includes the cleaning capability for hidden files and registry entries. Master Boot Record (MBR) rootkit detection, gives RootkitBuster the ability to detect hidden MBR content. It can spot all variants of MBR rootkit in the wild. MBR rootkits first began appearing in the wild late 2007. New variants continue to appear.
  • Trend Micro’s RUBotted – http://free.antivirus.com/rubotted/:
      Malicious software called Bots can secretly take control of computers and make them participate in networks called “Botnets.” These networks can harness massive computing power and Internet bandwidth to relay spam, attack web servers, infect more computers, and perform other illicit activities. RUBotted monitors your computer for suspicious activities and regularly checks with an online service to identify behavior associated with Bots. Upon discovering a potential infection, RUBotted prompts you to scan and clean your computer.
  • Sophos Anti RookKit – http://www.sophos.com/products/free-tools/sophos-anti-rootkit.html
  • chrootkit – http://www.chkrootkit.org/ (MAC and many linux/unix versions)
  • GMER – http://www.gmer.net/ – (Windows)

Email security

File and container/volume encryption

“Secure” file erasure

Privacy cleaners


Passwords management

Host-based (aka “Personal”) firewalls

More on this blog: IpTables – https://eikonal.wordpress.com/2011/01/24/iptables/ | Port Knocking – https://eikonal.wordpress.com/2010/10/05/port-knocking/ | Firewalls – https://eikonal.wordpress.com/2012/05/04/firewalls/

Web proxies


Process scanners


People killed to harvest their organs

Filed under: history, opression, past — sandokan65 @ 12:41


Excel files processing

Filed under: perl, scripting, transformers — Tags: — sandokan65 @ 23:55

Related here: Excel sortIP macro – https://eikonal.wordpress.com/2012/02/07/excel-sortip-macro/ | Excel to text – https://eikonal.wordpress.com/2011/02/14/excel-to-text/ | IT tips pages – https://eikonal.wordpress.com/2010/02/08/it-tips-pages/


Database security

Database auditing

Misc info


Music scores, tabs, …

Filed under: music — Tags: — sandokan65 @ 15:57

Related at this blog: Electronic Music – https://eikonal.wordpress.com/2011/04/25/electronic-music/ | Gypsy music – https://eikonal.wordpress.com/2011/01/05/gypsy-music/ | Psychodelic rock from 1970s – https://eikonal.wordpress.com/2010/07/12/psychodelic-rock-from-1970s/ | Streaming and other free music online – https://eikonal.wordpress.com/2010/01/04/streaming-and-other-free-music-online/


Filed under: life, paleontology — Tags: , — sandokan65 @ 13:53


Basic (programming language)

Filed under: basic, programming languages — Tags: , , — sandokan65 @ 15:38




Solar planetary system

Dwarf planets

Definitions (from “Pluto’s Dwarf Planet Family Could Get Bigger” by Ian O’Neill (Discovery News; 2010.04.09) – http://news.discovery.com/space/plutos-dwarf-planet-family-is-about-to-get-bigger.html)

  • The 2006 IAU definition of a dwarf planet states that such a body should be massive enough to achieve hydrostatic equilibrium, it must orbit the sun, but it cannot “clear its own orbit.”
  • The ‘potato-limit’: “the rule that they must be of certain brightness, dwarf planets have a minimum radius of 420 km (260 miles).”

All except Ceres are trans-Neptunians residing in the Kuipert belt.

Name Location Discovery details Orbit radius Orbital period Size (radius) Mass Length of the day Misc
Eris (= 2003 UB_313; initially called “Xena”) Kuipert belt
Pluto Kuipert belt 1930.02.18 by Clyde Tombaugh it has very excentric orbit, with aphelion = 7.375 x10^9 km = 49.305 AU and perihelion = 4.436 x10^9 km = 29.658 AU 90,613.305 days_{Earth} = 248.09 years_{Earth} = 14,164.4 days_{Pluto} 1,153 \pm 10 km = 0.18 R_{Earth} (1.305 \pm 0.007)\times 1022 kg = 0.002  M_{Earth} = 0.178 M_{Moon} 6.387 230 day_{Earth} = 6 \ d \ 9 \ h \ 17 \ m \ 36 \ s Has four satellites:

  • Hydra: discovered by Hubble telescope in 2005. 30 to 115km diameter.
  • Charon: discovered in 1978 by the US Naval Observatory. 1,200km diameter.
  • Nix: discovered by Hubble telescope in 2005. 30 to 115km diameter.
  • P4 (yet unnamed): diameter 13 to 34 km [of 8 to 21 miles]
Makemake Kuipert belt
Haumea Kuipert belt
Quaoar (= 2002 LM60; = 50000 Quaoar) Kuipert belt announced 2002.02.07 by Michael Brown and Chadwick Trujillo of Caltech ~ 6.5 x10^9 km = 4 x10^9 miles ~ 288 years_{Earth} ~ 650 km = 400 miles likely composition: made mostly of low-density ices mixed with rock
Sedna (= 90377 Sedna) Kuipert belt discovered in 2003
Ceres asteroid belt


Oort Cloud

a sphere one light year in radius stretching a quarter of the distance to Alpha Centauri

Potential planet: Tyche

Related here: Astronomy & Astrophysics – https://eikonal.wordpress.com/2011/05/09/astronomy-astrophysics/ | Astronomic tables and calculators – https://eikonal.wordpress.com/2010/01/28/astronomic-tables-and-calculators/ | Inside black holes – https://eikonal.wordpress.com/2011/04/12/inside-black-holes/ | Physics Sites – https://eikonal.wordpress.com/2010/02/12/physics-sites/



Heath kernels

Filed under: eikonal approximation, physics — Tags: , — sandokan65 @ 13:56
  • “Unbounded Laplacians on Graphs: Basic Spectral Properties and the Heat Equation” by Matthias Keller, Daniel Lenz (arXiv:1101.2979v1 [math.FA]; 2011.01.15) – http://arxiv.org/abs/1101.2979
      Abstract: We discuss Laplacians on graphs in a framework of regular Dirichlet forms. We focus on phenomena related to unboundedness of the Laplacians. This includes (failure of) essential selfadjointness, absence of essential spectrum and stochastic incompleteness.
  • “Note on basic features of large time behaviour of heat kernels” by Matthias Keller, Daniel Lenz, Hendrik Vogt, Radosław Wojciechowski (arXiv:1101.0373v1 [math.FA]; 2011.01.11) – http://arxiv.org/abs/1101.0373
      Abstract: Large time behaviour of heat semigroups (and more generally, of positive selfadjoint semigroups) is studied. Convergence of the semigroup to the ground state and of averaged logarithms of kernels to the ground state energy is shown in the general framework of positivity improving selfadjoint semigroups. This framework includes Laplacians on manifolds, metric graphs and discrete graphs.

Post-Newtonian gravity

  • Clifford M. Will’s papers on Post-Newtonian approach:
    • 0) “Generation of Post-Newtonian Gravitational Radiation via Direct Integration of the Relaxed Einstein Equations” by Clifford M. Will (arXiv:gr-qc/9910057v1; 1999.10.15) – http://arxiv.org/abs/gr-qc/9910057
        Abstract: The completion of a network of advanced laser-interferometric gravitational-wave observatories around 2001 will make possible the study of the inspiral and coalescence of binary systems of compact objects (neutron stars and black holes), using gravitational radiation. To extract useful information from the waves, such as the masses and spins of the bodies, theoretical general relativistic gravitational waveform templates of extremely high accuracy will be needed for filtering the data, probably as accurate as $O[(v/c)^6]$ beyond the predictions of the quadrupole formula. We summarize a method, called DIRE, for Direct Integration of the Relaxed Einstein Equations, which extends and improves an earlier framework due to Epstein and Wagoner, in which Einstein’s equations are recast as a flat spacetime wave equation with source composed of matter confined to compact regions and gravitational non-linearities extending to infinity. The new method is free of divergences or undefined integrals, correctly predicts all gravitational wave “tail” effects caused by backscatter of the outgoing radiation off the background curved spacetime, and yields radiation that propagates asymptotically along true null cones of the curved spacetime. The method also yields equations of motion through $O[(v/c)^4]$, radiation-reaction terms at $O[(v/c)^5]$ and $O[(v/c)^7]$, and gravitational waveforms and energy flux through $O[(v/c)^4]$, in agreement with other approaches. We report on progress in evaluating the $O[(v/c)^6]$ contributions.
    • 1) “Post-Newtonian Gravitational Radiation and Equations of Motion via Direct Integration of the Relaxed Einstein Equations. I. Foundations” by Michael E. Pati, Clifford M. Will (arXiv:gr-qc/0007087v1; 2000.07.31) – http://arxiv.org/abs/gr-qc/0007087
        Abstract: We present a self-contained framework called Direct Integration of the Relaxed Einstein Equations (DIRE) for calculating equations of motion and gravitational radiation emission for isolated gravitating systems based on the post-Newtonian approximation. We cast the Einstein equations into their “relaxed” form of a flat-spacetime wave equation together with a harmonic gauge condition, and solve the equations formally as a retarded integral over the past null cone of the field point (chosen to be within the near zone when calculating equations of motion, and in the far zone when calculating gravitational radiation). The “inner” part of this integral(within a sphere of radius {\cal R} \sim one gravitational wavelength) is approximated in a slow-motion expansion using standard techniques; the “outer” part, extending over the radiation zone, is evaluated using a null integration variable. We show generally and explicitly that all contributions to the inner integrals that depend on {\cal R} cancel corresponding terms from the outer integrals, and that the outer integrals converge at infinity, subject only to reasonable assumptions about the past behavior of the source. The method cures defects that plagued previous “brute-force” slow-motion approaches to motion and gravitational radiation for isolated systems. We detail the procedure for iterating the solutions in a weak-field, slow-motion approximation, and derive expressions for the near-zone field through 3.5 post-Newtonian order in terms of Poisson-like potentials.
    • 2) “Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. II. Two-body equations of motion to second post-Newtonian order, and radiation-reaction to 3.5 post-Newtonian order” by Michael E. Pati, Clifford M. Will (arXiv:gr-qc/0201001v1; 2001.12.31) – http://arxiv.org/abs/gr-qc/0201001
        Abstract: We derive the equations of motion for binary systems of compact bodies in the post-Newtonian (PN) approximation to general relativity. Results are given through 2PN order (order (v/c)^4 beyond Newtonian theory), and for gravitational radiation reaction effects at 2.5PN and 3.5PN orders. The method is based on a framework for direct integration of the relaxed Einstein equations (DIRE) developed earlier, in which the equations of motion through 3.5PN order can be expressed in terms of Poisson-like potentials that are generalizations of the instantaneous Newtonian gravitational potential, and in terms of multipole moments of the system and their time derivatives. All potentials are well defined and free of divergences associated with integrating quantities over all space. Using a model of the bodies as spherical, non-rotating fluid balls whose characteristic size s is small compared to the bodies’ separation r, we develop a method for carefully extracting only terms that are independent of the parameter s, thereby ignoring tidal interactions, spin effects, and internal self-gravity effects. Through 2.5PN order, the resulting equations agree completely with those obtained by other methods; the new 3.5PN back-reaction results are shown to be consistent with the loss of energy and angular momentum via radiation to infinity.
    • 3) “Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. III. Radiation reaction for binary systems with spinning bodies” by Clifford M. Will (arXiv:gr-qc/0502039v2; 2005.04.29) – http://arxiv.org/abs/gr-qc/0502039
        Abstract: Using post-Newtonian equations of motion for fluid bodies that include radiation-reaction terms at 2.5 and 3.5 post-Newtonian (PN) order (O[(v/c)^5] and O[(v/c)^7] beyond Newtonian order), we derive the equations of motion for binary systems with spinning bodies. In particular we determine the effects of radiation-reaction coupled to spin-orbit effects on the two-body equations of motion, and on the evolution of the spins. For a suitable definition of spin, we reproduce the standard equations of motion and spin-precession at the first post-Newtonian order. At 3.5PN order, we determine the spin-orbit induced reaction effects on the orbital motion, but we find that radiation damping has no effect on either the magnitude or the direction of the spins. Using the equations of motion, we find that the loss of total energy and total angular momentum induced by spin-orbit effects precisely balances the radiative flux of those quantities calculated by Kidder et al. The equations of motion may be useful for evolving inspiraling orbits of compact spinning binaries.
    • 4) “Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. IV. Radiation reaction for binary systems with spin-spin coupling” by Han Wang, Clifford M. Will (arXiv:gr-qc/0701047v2; 2007.03.16) – http://arxiv.org/abs/gr-qc/0701047
        Abstract: Using post-Newtonian equations of motion for fluid bodies that include radiation-reaction terms at 2.5 and 3.5 post-Newtonian (PN) order O[(v/c)^5] and O[(v/c)^7] beyond Newtonian order), we derive the equations of motion for binary systems with spinning bodies, including spin-spin effects. In particular we determine the effects of radiation-reaction coupled to spin-spin effects on the two-body equations of motion, and on the evolution of the spins. We find that radiation damping causes a 3.5PN order, spin-spin induced precession of the individual spins. This contrasts with the case of spin-orbit coupling, where there is no effect on the spins at 3.5PN order. Employing the equations of motion and of spin precession, we verify that the loss of total energy and total angular momentum induced by spin-spin effects precisely balances the radiative flux of those quantities calculated by Kidder et al.
    • 5) “Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. V. Evidence for the strong equivalence principle to second post-Newtonian order” by Thomas Mitchell, Clifford M. Will (arXiv:0704.2243v2 [gr-qc]; 2007.07.17)- http://arxiv.org/abs/0704.2243
        Abstract: Using post-Newtonian equations of motion for fluid bodies valid to the second post-Newtonian order, we derive the equations of motion for binary systems with finite-sized, non-spinning but arbitrarily shaped bodies. In particular we study the contributions of the internal structure of the bodies (such as self-gravity) that would diverge if the size of the bodies were to shrink to zero. Using a set of virial relations accurate to the first post-Newtonian order that reflect the stationarity of each body, and redefining the masses to include 1PN and 2PN self-gravity terms, we demonstrate the complete cancellation of a class of potentially divergent, structure-dependent terms that scale as s^{-1} and s^{-5/2}, where s is the characteristic size of the bodies. This is further evidence of the Strong Equivalence Principle, and supports the use of post-Newtonian approximations to derive equations of motion for strong-field bodies such as neutron stars and black holes. This extends earlier work done by Kopeikin.


Unix tricks

Filed under: unix — Tags: , , , , , , , , — sandokan65 @ 15:38


System information

Check cpu info:

    cat /proc/cpuinfo


To get the list of usernames with its user ID in formatted way:

     awk -F":" '{ print "username: " $1 "\t\tuid:" $3 }' /etc/passwd


Find the particular string from the list of files in current directory:

    cd /etc
    for i in $(find -type f); do grep -iH nfsnobody $i; done


    grep -iH nfsnobody *

Counting words

Get the no of occurrences of particular word in file:

    awk '/ServerName/ {i=i+1} END {print i}' /etc/httpd/conf/httpd.conf
    grep ServerName /etc/httpd/conf/httpd.conf


To delete resources of semaphore arrays from memory:

    ipcs -s | 
    grep apache | 
    perl -e 'while () { @a=split(/\s+/); print`ipcrm sem $a[1]`}'

Convering Unix timestamp to human readable format

All one needs here is neatly summarized by Anton Olson in his blog posting “BASH: Convert Unix Timestamp to a Date” – http://www.antonolsen.com/2006/04/06/bash-convert-unix-timestamp-to-a-date/:

  • 1) perl -e “require ‘ctime.pl’; print &ctime($EPOCH);” – where ctime is a Perl module (available where?)
  • 2) perl -e “print scalar(localtime($EPOCH))”
  • 3) echo $EPOCH|awk ‘{print strftime(“%c”,$1)}’
  • 4) # date -d @1000000042 on Linux (and Cygwin)
  • 5) $ date -d ’1970-01-01 sec’. It is important to use the GMT tag:
    • #date -d ’1970-01-01 1000000000 sec GMT’ with output: Sat Sep 8 20:46:40 CDT 2001
    • #date -d ’1970-01-01 1000000000 sec’ gives output: Sun Sep 9 02:46:40 CDT 2001
  • 6) $ date -r 1229519950 – on FreeBSD

The third method works fine if you have available only shell (e.g. working in Cygwin) and does not require Perl interpreter. For example:

    In: echo 101000070 | awk '{print strftime("%c",$1)}'
    Out: Wed Mar 14 19:34:30 1973


To check whether perl module is installed correctly or not: if all is correct then output of this command nothing

    perl -e 'require Mail::SPF::Query'

To install CPAN module:

    cpan> install Mail::SPF::Query
    CPAN: Storable loaded ok
    Going to read /root/.cpan/Metadata
    Database was generated on Thu, 24 Nov 2005 14:54:20 GMT
    Mail::SPF::Query is up to date.

IP Addresses

To get the list of IP addresses in the server:

    ifconfig | 
    grep -vw inet6 | 
    grep -w inet | 
    cut -d : -f 2 | 
    cut -d \ -f 1

Find list of IP address along with eth device and network mask:

    ifconfig | 
    cut -d " " -f1,12,16 | 
    grep -A 1 eth | 
    tr -d - | 
    tr -s "\n" |sed -e :a -e N -e 's/\n/ /'

hard disk

Know the performance of your HardDisk: change the device address as per your servers configuration

    hdparm -Tt /dev/sda


Get the customized output of raw accesslog of httpd: Navigate the folder where your http access log reside, then execute following:

    tail -f access_log | 
    awk '{if ($11 ~"\"-\"") print $1, $7, $12; else print $1, $10, $11, $12}'

Checking SSH failure log (in GNU/Linux Debian)

    /bin/cat /var/log/auth.log  |
    grep sshd:auth |
    grep failure |
    awk '{print $1"-" $2 "-" $3 "-->" $12 "->" $14 "->" $15}'

Open connections

The details of the present http connections can be found by using:

    netstat -plan | 
    grep ":80 " | 
    awk {'print $5'} |
    awk -F: {'print $1'}|
    cat /proc/net/ip_conntrack | 
    grep "port=80" | 
    wc -l

Number of connection from the particular IP addfess:

    netstat -ntu | awk '{print $5}'| cut -d: -f1 | sort | uniq -c | sort -nr | more

No of conections:

    netstat -alntp
    /sbin/ldconfig /usr/local/lib - Update the system linker cache

Real Time Network Activity Examples:

    root# watch -d "netstat -nalp |grep -v DGRAM |grep -v STREAM |grep -v LISTEN"
    root# watch "netstat -nalp"|grep ":TCP PORT Number"
    root# watch "netstat -nalp"|grep ":22"

Port scanning

Port scanning using nmap:
You can customized it to get more informative output

    nmap -sS localhost -

instead host localhost, it could be IP address of another server which is in question

Bash loops

You can execute bash command a certain number of times by using something similar to the following:

    n=0;while test -$n -gt -10; do echo n=$n; n=$[$n+1]; done

that code will print “n=0”, “n=1”, and so on 10 times.

Directory content

Only get the listing of directories:

    ls -F $1 | 
    grep \/ | 
    sed -e 's/\/$/4/g'

Killing processes

Kill program one time click base keyword:

    for a in $( ps aux | 
    grep  "some-thing-text" | 
    awk '{ print $2 }'); do kill $a; done;

Kill crontab processes:

    for a in $( ps aux | grep  "/USR/SBIN/CRON" | awk '{ print $2 }'); do kill $a; done;

Environment variables

CDPATH env variable, if it is set for instance

    [bash ~]$ export CDPATH=/usr/local/apache

when you enter from any directory you’re in

    [bash /var/log]$ cd htdocs

it will take you to /usr/local/apache/htdocs.

Bash completion, command repetition and command history

  • !! at the command shell executes the last executed command
  • !m – executes the last command in history that starts with m for instance mail
  • !m:p – will print what was the last command that starts with m


  • hitting twice z while holding a shift key in vi in command mode saves the edited file and quits vi

File dates

Updating atime on file foo (e.g. to 21:00 of Jan 1 1970):

    touch -t 197001012100 foo

help, man, apropos

Redirect a rather big man page to a text file in easy readable format:

    man manpage | col -b > manpage.txt

Conversion DOS to UNIX and vice versa

Getting rid off annoying ^M (CTRL-M) in DOS-like files:

    tr -d "15"  /unixfile

In vi editor use search-and-replace command:


To get ^M (in vi)you press CTRL+V+M

Related here: Unix system administration – https://eikonal.wordpress.com/2011/03/02/unix-system-administration/ | Cygwin stuff – https://eikonal.wordpress.com/2010/07/12/cygwin-stuff | MS Windows Registry transversal by Cygwin – https://eikonal.wordpress.com/2011/03/01/registry-transversal-by-cygwin

Related here: Scripting languages – https://eikonal.wordpress.com/2010/06/15/awk-sed/ | Unix tricks – https://eikonal.wordpress.com/2011/02/15/unix-tricks/ | SED tricks – https://eikonal.wordpress.com/2010/10/05/sed-tricks/ | Memory of things disappearing > nmap stuff > getports.awk – https://eikonal.wordpress.com/2010/06/23/memory-of-things-disappearing-nmap-stuff-getports-awk/ | AWK – https://eikonal.wordpress.com/2011/09/30/awk/


Excel to text

Filed under: perl, scripting, tools, transformers — Tags: , — sandokan65 @ 14:11
  • excel2txt (by Ken Youens-Clark) – http://search.cpan.org/~kclark/excel2txt/excel2txt [Perl] – convert Excel data to delimited text files
    • Example use:

      > excel2txt PasswdFiles.xls
      Processing PasswdFiles.xls
      Writing 'passwdfiles-fiapp1.txt'
      Writing 'passwdfiles-fiapp2.txt'
      Writing 'passwdfiles-fiapp3.txt'
      Writing 'passwdfiles-fiapp4.txt'
      Writing 'passwdfiles-fiapp6.txt'
      Writing 'passwdfiles-fiapp7.txt'
      Writing 'passwdfiles-fiapp8.txt'
      Writing 'passwdfiles-fiapp9.txt'
      Writing 'passwdfiles-fidb1.txt'
      Writing 'passwdfiles-fidb2.txt'
      Writing 'passwdfiles-fidb3.txt'
      Writing 'passwdfiles-fidb4.txt'
      Writing 'passwdfiles-fiweb1.txt'
      Writing 'passwdfiles-fiweb2.txt'
      Writing 'passwdfiles-fiweb3.txt'
      Writing 'passwdfiles-fiweb4.txt'
      Done, processed 1 Excel file, created 16 data files.

Related here: Excel sortIP macro – https://eikonal.wordpress.com/2012/02/07/excel-sortip-macro/ | Excel files processing – https://eikonal.wordpress.com/2011/02/25/excel-files-processing/ | IT tips pages – https://eikonal.wordpress.com/2010/02/08/it-tips-pages/


Vacuum energy

Filed under: physics, qft — Tags: , , — sandokan65 @ 22:57


File systems over anything

Filed under: Uncategorized, web tools — Tags: , , — sandokan65 @ 16:25


Filed under: infosec, security hardening, unix — Tags: , — sandokan65 @ 11:38
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