8 bits

Create diagrams with multi-platform DIA

Do you want people to know what you're developing ? I have found a nice free (and multi-platform) program to make diagrams (in order to make things a lot more understandable). The name of the tool is Dia and you can find all information at:

http://live.gnome.org/Dia (Linux)
http://dia-installer.de/index_en.html (Windows)

Dia is roughly inspired by the commercial Windows program 'Visio', though more geared towards informal diagrams for casual use. It can be used to draw many different kinds of diagrams and has standard sheets for a.o. network, cisco, sybase, database, UML etc. etc. I think it's really a great product !

About base64

The new release of UltraEdit offers the possibility to encode / decode files with base46. I want to know more about it. I found nice information in this file from Chris Melnick  (2004).

Windows: simple web scraping with Wget.exe

I just stumbled upon wget.exe, a free, GNU win32 edition of the great wget tool which I used under Linux a lot. Wget is a very simple tool to scrape webpages.

How does it work:

wget.exe "http://somesite.com/somepage.html" -O yourfile.htm

Other variables:

wget --help
GNU Wget 1.11.4, a non-interactive network retriever.
Usage: wget [OPTION]... [URL]...

Mandatory arguments to long options are mandatory for short options too.

Startup:
  -V,  --version           display the version of Wget and exit.
  -h,  --help              print this help.
  -b,  --background        go to background after startup.
  -e,  --execute=COMMAND   execute a `.wgetrc'-style command.

Logging and input file:
  -o,  --output-file=FILE    log messages to FILE.
  -a,  --append-output=FILE  append messages to FILE.
  -d,  --debug               print lots of debugging information.
  -q,  --quiet               quiet (no output).
  -v,  --verbose             be verbose (this is the default).
  -nv, --no-verbose          turn off verboseness, without being quiet.
  -i,  --input-file=FILE     download URLs found in FILE.
  -F,  --force-html          treat input file as HTML.
  -B,  --base=URL            prepends URL to relative links in -F -i file.

Download:
  -t,  --tries=NUMBER            set number of retries to NUMBER (0 unlimits).
       --retry-connrefused       retry even if connection is refused.
  -O,  --output-document=FILE    write documents to FILE.
  -nc, --no-clobber              skip downloads that would download to existing files.
  -c,  --continue                resume getting a partially-downloaded file.
       --progress=TYPE           select progress gauge type.
  -N,  --timestamping            don't re-retrieve files unless newer than local.
  -S,  --server-response         print server response.
       --spider                  don't download anything.
  -T,  --timeout=SECONDS         set all timeout values to SECONDS.
       --dns-timeout=SECS        set the DNS lookup timeout to SECS.
       --connect-timeout=SECS    set the connect timeout to SECS.
       --read-timeout=SECS       set the read timeout to SECS.
  -w,  --wait=SECONDS            wait SECONDS between retrievals.
       --waitretry=SECONDS       wait 1..SECONDS between retries of a retrieval 
       --random-wait             wait from 0...2*WAIT secs between retrievals.
       --no-proxy                explicitly turn off proxy.
  -Q,  --quota=NUMBER            set retrieval quota to NUMBER.
       --bind-address=ADDRESS    bind to ADDRESS (hostname or IP) on local host 
       --limit-rate=RATE         limit download rate to RATE.
       --no-dns-cache            disable caching DNS lookups.
       --restrict-file-names=OS  restrict chars in file names to ones OS allows 
       --ignore-case             ignore case when matching files/directories.
       --user=USER               set both ftp and http user to USER.
       --password=PASS           set both ftp and http password to PASS.

Directories:
  -nd, --no-directories           don't create directories.
  -x,  --force-directories        force creation of directories.
  -nH, --no-host-directories      don't create host directories.
       --protocol-directories     use protocol name in directories.
  -P,  --directory-prefix=PREFIX  save files to PREFIX/...
       --cut-dirs=NUMBER          ignore NUMBER remote directory components.

HTTP options:
       --http-user=USER        set http user to USER.
       --http-password=PASS    set http password to PASS.
       --no-cache              disallow server-cached data.
  -E,  --html-extension        save HTML documents with `.html' extension.
       --ignore-length         ignore `Content-Length' header field.
       --header=STRING         insert STRING among the headers.
       --max-redirect          maximum redirections allowed per page.
       --proxy-user=USER       set USER as proxy username.
       --proxy-password=PASS   set PASS as proxy password.
       --referer=URL           include `Referer: URL' header in HTTP request.
       --save-headers          save the HTTP headers to file.
  -U,  --user-agent=AGENT      identify as AGENT instead of Wget/VERSION.
       --no-http-keep-alive    disable HTTP keep-alive (persistent connections)
       --no-cookies            don't use cookies.
       --load-cookies=FILE     load cookies from FILE before session.
       --save-cookies=FILE     save cookies to FILE after session.
       --keep-session-cookies  load and save session (non-permanent) cookies.
       --post-data=STRING      use the POST method; send STRING as the data.
       --post-file=FILE        use the POST method; send contents of FILE.
       --content-disposition   honor the Content-Disposition header when choosing local file names (EXPERIMENTAL).
       --auth-no-challenge     Send Basic HTTP authentication information without first waiting for the server's challenge.

HTTPS (SSL/TLS) options:
       --secure-protocol=PR     choose secure protocol, one of auto, SSLv2, SSLv3, and TLSv1.
       --no-check-certificate   don't validate the server's certificate.
       --certificate=FILE       client certificate file.
       --certificate-type=TYPE  client certificate type, PEM or DER.
       --private-key=FILE       private key file.
       --private-key-type=TYPE  private key type, PEM or DER.
       --ca-certificate=FILE    file with the bundle of CA's.
       --ca-directory=DIR       directory where hash list of CA's is stored.
       --random-file=FILE       file with random data for seeding the SSL PRNG.
       --egd-file=FILE          file naming the EGD socket with random data.

FTP options:
       --ftp-user=USER         set ftp user to USER.
       --ftp-password=PASS     set ftp password to PASS.
       --no-remove-listing     don't remove `.listing' files.
       --no-glob               turn off FTP file name globbing.
       --no-passive-ftp        disable the "passive" transfer mode.
       --retr-symlinks         when recursing, get linked-to files (not dir).
       --preserve-permissions  preserve remote file permissions.

Recursive download:
  -r,  --recursive          specify recursive download.
  -l,  --level=NUMBER       maximum recursion depth (inf or 0 for infinite).
       --delete-after       delete files locally after downloading them.
  -k,  --convert-links      make links in downloaded HTML point to local files.
  -K,  --backup-converted   before converting file X, back up as X.orig.
  -m,  --mirror             shortcut for -N -r -l inf --no-remove-listing.
  -p,  --page-requisites    get all images, etc. needed to display HTML page.
       --strict-comments    turn on strict (SGML) handling of HTML comments.

Recursive accept/reject:
  -A,  --accept=LIST               comma-separated list of accepted extensions.
  -R,  --reject=LIST               comma-separated list of rejected extensions.
  -D,  --domains=LIST              comma-separated list of accepted domains.
       --exclude-domains=LIST      comma-separated list of rejected domains.
       --follow-ftp                follow FTP links from HTML documents.
       --follow-tags=LIST          comma-separated list of followed HTML tags.
       --ignore-tags=LIST          comma-separated list of ignored HTML tags.
  -H,  --span-hosts                go to foreign hosts when recursive.
  -L,  --relative                  follow relative links only.
  -I,  --include-directories=LIST  list of allowed directories.
  -X,  --exclude-directories=LIST  list of excluded directories.
  -np, --no-parent                 don't ascend to the parent directory.

Mail bug reports and suggestions to <bug-wget@gnu.org>.

PDF split and merge

I have found a great open source tool to split or merge PDF documents: PDFSAM.

PDF Split and Merge is an easy to use tool to merge and split pdf documents. Console and GUI versions are available. The GUI is written in Java Swing and it provides functions to select files and set options.

HEX and Unicode

I just noticed the many similarities betwee hexadecimal and unicode (basic latin). I have made a list:

Text - Hex - Unicode
a - 61 - 0061
b - 62 - 0062
c - 63 - 0063
d - 64 - 0064
e - 65 - 0065
f - 66 - 0066
g - 67 - 0067
h - 68 - 0068
i - 69 - 0069
j - 6A - 006A
k - 6B - 006B
l - 6C - 006C
m - 6D - 006D
n - 6E - 006E
o - 6F - 006F
p - 70 - 0070
q - 71 - 0071
r - 72 - 0072
s - 73 - 0073
t - 74 - 0074
u - 75 - 0075
v - 76 - 0076
w - 77 - 0077
x - 78 - 0078
y - 79 - 0079
z - 7A - 007A

Keep passwords out of your site files

Today I read an interesting article in O'Reilly's PHP Cookbook: Keeping Passwords Out of Your Site Files. When your passwords are in a hidden file (a file which can't normally be reached from the internet), it's much harder for unprivileged visitors to get your valuable credentials. In this example: username and password for your MySQL database.

How to do this:

First, create a file in /usr/local/apache/
(this folder can't be reached from the internet without SSH or FTP root permissions). For example, name this file database-passwords. The contents of this file is:

SetEnv DB_USER "username"
SetEnv DB_PASSWORD "password"

where "username" and "password" are your real username and password.

Add this line to the appropriate <VirtualHost> settings in /etc/apache2/apache2.conf:

Include /usr/local/apache/database-passwords 

Restart Apache

Now, make a folder in your website root named mysql
add a file to this folder, named .htaccess (the contents of this file: deny from all), also add a file to the mysql folder named mysql-details.php, the contents of this file is:

<?php
$host = "127.0.0.1";
$user = $_SERVER['DB_USER'];
$password = $_SERVER['DB_PASSWORD'];
$dbname = "mydatabase";
$tablename = "mytable";
$db = mysql_connect($host, $user, $password) or die("no connection");
mysql_select_db($dbname,$db);
?>

where mydatabase and mytable are the real name for your database and table

Add this line to the php file in which you want to call the MySQL username and password:

include("mysql/mysql-details.php");

A big fat warning:

be sure no file exists in your website folder with the contents <?php phpinfo() ?> as with this command your credentials are revealed to the world (in the Apache Environment sector). Also, make sure not to expose the contents of $_SERVER in other ways, such as with the print_r() function. If you can prevent this, you're ready to go and you can be a bit more certain that your MySQL login credentials are safe from unprivileged eyes.

Open docx bestanden in Word (Office 2003)

Je kunt eenvoudig docx bestanden (gemaakt door Word uit Office 2007) openen met Word uit Office 2003, door de compatibility pack te downloaden en te installeren. Hierna kun je een docx bestand openen en onder Word 2003 opslaan als doc bestand.

Bescherm downloadmappen met mod_rewrite en .htaccess

zie mijn oplossing in het Codecharge forum:

http://forums.yessoftware.com/posts.php?post_id=101099

Snipplr Code Snippets

Ik liep zojuist tegen de site Snipplr.com aan, een prachtige collectie codes voor de (wannabee) programmeurs en webdesigners onder ons. Onder het motto: beter goed gejat dan slecht verzonnen kun je de gevonden codes als favoriet aanmerken en gebruiken in je eigen ontwerpen. En als Snipplr het niet heeft, dan kun je altijd nog bij Krugle.com terecht.

 

Geen DVD'tjes meer versturen dankzij Microsoft Skydrive

Skydrive, de sinds dit jaar actieve gratis opslagdienst van Microsoft, maakt het mogelijk om tot 5GB aan data on-line te delen met anderen. Uiteraard kun je altijd je twijfels hebben bij de veiligheid van dergelijke diensten. Echter, als je gebruik maakt van versleutelde bestanden kun je Skydrive uitermate goed gebruiken om data ter grootte van een complete DVD uit te wisselen. Afzonderlijke bestanden mogen ten hoogste 50MB groot zijn (een iso uitwisselen is er dus niet bij, al kun je altijd 'rarren' en deelbestanden van 50MB maken.). Je kunt gebruik maken van wachtwoordbeveiliging en zelf bepalen aan wie je de bestanden ter beschikking stelt. Als je vervolgens afspreekt dat de ander je moet bellen om het wachtwoord voor het versleutelde bestand te krijgen, dan kun je relatief veilig data uitwisselen. Uiteraard moet je er altijd voor zorgen dat de encryptie van de data sterk genoeg is.