WEB 2.0Ooooh

One bad thing about web is you read about one version which took more than years of time by more than a million researchers... in a mins time you come to see web 3.0.Well we will talk about WEB 3.0 in next post but for now just 2.0

Web 2.0 is a base on the web 1.0 with the same networking techniques giving more enhancements to the user interaction with the net. Web 2.0 sites often feature a rich, user-friendly interface based on below tags. Any internet applications made using the concept of web 2.0 are called RIA.

Rich internet applications techniques such as AJAX, Adobe Flash, Flex, JavaFX, Curl and Silverlight have evolved that have the potential to improve the user-experience in browser-based applications. Specialized protocols such as FOAF and XFN (I have never gone through this protocols, but I have given links below.) extend the functionality of sites or permit end-users to interact without centralized websites.

http://en.wikipedia.org/wiki/FOAF_%28software%29

http://en.wikipedia.org/wiki/XHTML_Friends_Network

ADOBE AIR: I was in air at ninth cloud when i read about this.Dont miss the e-bay application.Its amazing.Best part of it is the response facts are similar to javascript and very fast than cache implementation.These applications are created as on-line application but there basic uses are for desktop deployment.

http://en.wikipedia.org/wiki/Adobe_Integrated_Runtime#Applications

ADOBE FLEX: FLEX in simple wrds HTML + FLASH. being from the networking back ground I was not very much impressed with this outcome as it turns a web application very heavy n slow to handle but advantageous is the look-n-feel u get from this, it make's the user crazy about the site.Check out lee burner site. You will stick to that site more than a day..It’s an SDK to develop WEB2.0 with all the rich contexts. In context of web1.0 he can match html as flex pages and java script which dynamic content as coldfusion ability from ADOBE

http://en.wikipedia.org/wiki/Adobe_Flex

MICROSOFT SILVER LIGHT: This not a framework rather it’s a browser plugin.Its just a sibling of Adobe flash with more good performance techniques. Worst part of it is it does not support any OS based browsers especially safari and other Linux based browsers. So it is also called browser-unsafe plug-in.

http://en.wikipedia.org/wiki/Microsoft_Silverlight

JAVAFX: This is my favorite... :)

It is a RIA frame work with similar to flex but performance was its very good than flex as they should be accessible by mobile applications that is using JAVAME.

If anyone wants to know internal content of any above applications .This site below is very good and informative

http://www.devx.com/RichInternetApps/Article/35208/1954?pf=true

There are few more like CURL, open lazzalo..You may think who is she to give her comments.Well these are just my comments.Do drop in your comments in the comments column.

AM I FAR?

VNC akka virtual network computing. Do you feel your far from your computer. just relax at your lappi and use technology .VNC server is basically remote computing .IT is not heavy like any refelction or Hummpi. Above that is is inbuilt in my fav OS linux esp fedora.... :)

Here is the awesome link which explains about VNC and gives how to set it up?

http://fedoranews.org/tchung/vnc/

DUMP MYSQL

OOoops!!!! did i say something wrong. Mysql is the best SQL database with lot of inbuilt functions, not just leaving you to the drag and drop stuff put encourages you to use your very own brain and come with queries!!! well thsi blog is not about to encourage and to pomp and show about mysql but this is where i will say how to take backup of your mysql database.

LINUX BASED USERS:The most common use of mysqldump is probably for making a backup of an entire database:

shell> mysqldump --opt db_name > backup-file.sql

You can read the dump file back into the server like this:

shell> mysql db_name < backup-file.sql

Or like this:

shell> mysql -e "source /path-to-backup/backup-file.sql" db_name

mysqldump is also very useful for populating databases by copying data
from one MySQL server to another:

shell> mysqldump --opt db_name | mysql --host=remote_host -C db_name

It is possible to dump several databases with one command:

shell> mysqldump --databases db_name1 [db_name2 ...] > my_databases.sql

If you want to dump all databases, use the --all-databases option:

shell> mysqldump --all-databases > all_databases.sql

oKE OKE YOUR AN WINDOWS USER:

"C:\Program Files\MySQL\MySQL Server 5.0\bin"\mysqldump -uBackup -pBackup %db% >c:\backup\%db%.sql

Scheduling Tasks in ruby/rails

Whether it is retrieving an RSS feed, or performing some maintenance operations on your system or a Rails app, an easy to use scheduler is a must have. Motivated by this need, I did some scouring and came up with a few nifty ways to accomplish the task. Now, before we go on, it’s worth mentioning that all *nix based systems have the advantage of a cron daemon which can perform this job quiet effectively. However, building standalone scripts is not always the best way to get things done, hence there are some valid cases where replicating this functionality can, in fact, be very useful.

Thread based scheduler

The most obvious way to schedule a task from within your program is to either loop it forever with a periodic sleep interval, or launch a separate thread which will perform the same job:

> thread_scheduler.rb

require 'fastthread'

t = Thread.new do
 while true do
   p 'perform task'
   sleep 5
 end
end

t.join # wait for thread to exit (never, in this case) 

Create a new thread, perform the task, sleep for 5 seconds, and repeat forever. Launching one of these inside a Tier IV datacenter will ensure that your tasks are executed until the next nuclear winter. (Or, until your thread crashes - whichever is more likely!)

Flexible scheduling in Ruby

While threads are easy to use, they are still not very intuitive. After some searching, I stumbled across the OpenWFEru project, which implements a really nifty standalone-ready scheduler. Take a look yourself:

> open_wfe.rb

require 'openwfe/util/scheduler'
include OpenWFE

scheduler = Scheduler.new
scheduler.start

# Simple usage
scheduler.schedule_every('2s') { p 'every 2 seconds' }
scheduler.schedule_every('5m') { p 'every 5 minutes' }
scheduler.schedule_every('1d') { p 'every day' }

# More fine-grained control + schedule task once.
scheduler.schedule_in('3d2m10s') do
   p 'after 3 days 2 minutes and 10 seconds stopping the scheduler and exiting...'
   scheduler.do_stop
end

# Cron-string scheduling. There is something for everyone here!
scheduler.schedule('1-60 * * * *') do
   p 'perform task'
end

scheduler.join

OpenWFEru scheduler is now also available as a standalone gem thanks to John Mettraux.

Each call to the scheduler queues your request on the main thread, which then spawns a separate thread for each task when the time is right. It’s definitely quite a bit cleaner, but the rich parse engine is by far the best part. Even a non-programmer will understand this code. Plus, and if thats your preference, you have the ability of providing a cron-like string! Also, it is important to note that if you schedule a task for every 2 seconds, but the task itself takes 3 seconds, then the job will be performed every 5 seconds! If you really do need 2 second intervals, simply create a new thread in your scheduled block, and let it run.

Scheduling in Rails

Finally, if you want to schedule tasks in Rails, then BackgrounDRB is your new best friend. Ezra wrote a great guide for it, and I highly recommend that you check it out. As of 0.2.1, backgroundrb added support for easy job scheduling via a yaml config file (conf/backgroundrb_schedules.yml). Here is a sample:

> backgroundrb_schedules.yml

scheduled_task:
 :class: :scheduled_task_worker
 :worker_method: :do_work
 :trigger_args:
   :start: <%= Time.now + 10.minutes %>
   :repeat_interval: <%= 1.hour %>

Note that you can have multiple workers, running at different intervals, simply duplicate the worker in your config and give it a different name. Then, call up the generator to create the file itself and navigate to lib/workers. Again, here is a sample implementation:

> scheduled_task.rb

class ScheduledTaskWorker < BackgrounDRb::Worker::RailsBase

 def do_work(args)
   # RailsBase worker gives this class access to all ActiveRecord models.. go wild!
   p 'perform task'
 end

end
ScheduledTaskWorker.register


Thanks to http://openwferu.rubyforge.org/.. concepts were clear from this site

Find HOW?

SYNOPSIS

find [path...] [expression]

DESCRIPTION

This manual page documents the GNU version of find. find searches the directory tree rooted at each given file name by evaluating the given expression from left to right, according to the rules of precedence (see section OPERATORS), until the outcome is known (the left hand side is false for and operations, true for or), at which point find moves on to the next file name.

The first argument that begins with `-', `(', `)', `,', or `!' is taken to be the beginning of the expression; any arguments before it are paths to search, and any arguments after it are the rest of the expression. If no paths are given, the current directory is used. If no expression is given, the expression `-print' is used.

find exits with status 0 if all files are processed successfully, greater than 0 if errors occur.

EXPRESSIONS

The expression is made up of options (which affect overall operation rather than the processing of a specific file, and always return true), tests (which return a true or false value), and actions (which have side effects and return a true or false value), all separated by operators. -and is assumed where the operator is omitted. If the expression contains no actions other than -prune, -print is performed on all files for which the expression is true.

OPTIONS

All options always return true. They always take effect, rather than being processed only when their place in the expression is reached. Therefore, for clarity, it is best to place them at the beginning of the expression.

-daystart

Measure times (for -amin, -atime, -cmin, -ctime, -mmin, and -mtime) from the beginning of today rather than from 24 hours ago.

-depth

Process each directory's contents before the directory itself.

-follow

Dereference symbolic links. Implies -noleaf.

-help, --help

Print a summary of the command-line usage of find and exit.

-maxdepth levels

Descend at most levels (a non-negative integer) levels of directories below the command line arguments. `-maxdepth 0' means only apply the tests and actions to the command line arguments.

-mindepth levels

Do not apply any tests or actions at levels less than levels (a non-negative integer). `-mindepth 1' means process all files except the command line arguments.

-mount

Don't descend directories on other filesystems. An alternate name for -xdev, for compatibility with some other versions of find.

-noleaf

Do not optimize by assuming that directories contain 2 fewer subdirectories than their hard link count. This option is needed when searching filesystems that do not follow the Unix directory-link convention, such as CD-ROM or MS-DOS filesystems or AFS volume mount points. Each directory on a normal Unix filesystem has at least 2 hard links: its name and its `.' entry. Additionally, its subdirectories (if any) each have a `..' entry linked to that directory. When find is examining a directory, after it has statted 2 fewer subdirectories than the directory's link count, it knows that the rest of the entries in the directory are non-directories (`leaf' files in the directory tree). If only the files' names need to be examined, there is no need to stat them; this gives a significant increase in search speed.

-version, --version

Print the find version number and exit.

-xdev

Don't descend directories on other filesystems.

TESTS

Numeric arguments can be specified as

+n

for greater than n,

-n

for less than n,

n

for exactly n.

-amin n

File was last accessed n minutes ago.

-anewer file

File was last accessed more recently than file was modified. -anewer is affected by -follow only if -follow comes before -anewer on the command line.

-atime n

File was last accessed n*24 hours ago.

-cmin n

File's status was last changed n minutes ago.

-cnewer file

File's status was last changed more recently than file was modified. -cnewer is affected by -follow only if -follow comes before -cnewer on the command line.

-ctime n

File's status was last changed n*24 hours ago.

-empty

File is empty and is either a regular file or a directory.

-false

Always false.

-fstype type

File is on a filesystem of type type. The valid filesystem types vary among different versions of Unix; an incomplete list of filesystem types that are accepted on some version of Unix or another is: ufs, 4.2, 4.3, nfs, tmp, mfs, S51K, S52K. You can use -printf with the %F directive to see the types of your filesystems.

-gid n

File's numeric group ID is n.

-group gname

File belongs to group gname (numeric group ID allowed).

-ilname pattern

Like -lname, but the match is case insensitive.

-iname pattern

Like -name, but the match is case insensitive. For example, the patterns `fo*' and `F??' match the file names `Foo', `FOO', `foo', `fOo', etc.

-inum n

File has inode number n.

-ipath pattern

Like -path, but the match is case insensitive.

-iregex pattern

Like -regex, but the match is case insensitive.

-links n

File has n links.

-lname pattern

File is a symbolic link whose contents match shell pattern pattern. The metacharacters do not treat `/' or `.' specially.

-mmin n

File's data was last modified n minutes ago.

-mtime n

File's data was last modified n*24 hours ago.

-name pattern

Base of file name (the path with the leading directories removed) matches shell pattern pattern. The metacharacters (`*', `?', and `[]') do not match a `.' at the start of the base name. To ignore a directory and the files under it, use -prune; see an example in the description of -path.

-newer file

File was modified more recently than file. -newer is affected by -follow only if -follow comes before -newer on the command line.

-nouser

No user corresponds to file's numeric user ID.

-nogroup

No group corresponds to file's numeric group ID.

-path pattern

File name matches shell pattern pattern. The metacharacters do not treat `/' or `.' specially; so, for example,
find . -path './sr*sc'
will print an entry for a directory called './src/misc' (if one exists). To ignore a whole directory tree, use -prune rather than checking every file in the tree. For example, to skip the directory `src/emacs' and all files and directories under it, and print the names of the other files found, do something like this:
find . -path './src/emacs' -prune -o -print

-perm mode

File's permission bits are exactly mode (octal or symbolic). Symbolic modes use mode 0 as a point of departure.

-perm -mode

All of the permission bits mode are set for the file.

-perm +mode

Any of the permission bits mode are set for the file.

-regex pattern

File name matches regular expression pattern. This is a match on the whole path, not a search. For example, to match a file named `./fubar3', you can use the regular expression `.*bar.' or `.*b.*3', but not `b.*r3'.

-size n[bckw]

File uses n units of space. The units are 512-byte blocks by default or if `b' follows n, bytes if `c' follows n, kilobytes if `k' follows n, or 2-byte words if `w' follows n. The size does not count indirect blocks, but it does count blocks in sparse files that are not actually allocated.

-true

Always true.

-type c

File is of type c:

b

block (buffered) special

c

character (unbuffered) special

d

directory

p

named pipe (FIFO)

f

regular file

l

symbolic link

s

socket

D

door (Solaris)

-uid n

File's numeric user ID is n.

-used n

File was last accessed n days after its status was last changed.

-user uname

File is owned by user uname (numeric user ID allowed).

-xtype c

The same as -type unless the file is a symbolic link. For symbolic links: if -follow has not been given, true if the file is a link to a file of type c; if -follow has been given, true if c is `l'. In other words, for symbolic links, -xtype checks the type of the file that -type does not check.

ACTIONS

-exec command ;

Execute command; true if 0 status is returned. All following arguments to find are taken to be arguments to the command until an argument consisting of `;' is encountered. The string `{}' is replaced by the current file name being processed everywhere it occurs in the arguments to the command, not just in arguments where it is alone, as in some versions of find. Both of these constructions might need to be escaped (with a `\') or quoted to protect them from expansion by the shell. The command is executed in the starting directory.

-fls file

True; like -ls but write to file like -fprint.

-fprint file

True; print the full file name into file file. If file does not exist when find is run, it is created; if it does exist, it is truncated. The file names ``/dev/stdout'' and ``/dev/stderr'' are handled specially; they refer to the standard output and standard error output, respectively.

-fprint0 file

True; like -print0 but write to file like -fprint.

-fprintf file format

True; like -printf but write to file like -fprint.

-ok command ;

Like -exec but ask the user first (on the standard input); if the response does not start with `y' or `Y', do not run the command, and return false.

-print

True; print the full file name on the standard output, followed by a newline.

-print0

True; print the full file name on the standard output, followed by a null character. This allows file names that contain newlines to be correctly interpreted by programs that process the find output.

-printf format

True; print format on the standard output, interpreting `\' escapes and `%' directives. Field widths and precisions can be specified as with the `printf' C function. Unlike -print, -printf does not add a newline at the end of the string. The escapes and directives are:

\a

Alarm bell.

\b

Backspace.

\c

Stop printing from this format immediately and flush the output.

\f

Form feed.

\n

Newline.

\r

Carriage return.

\t

Horizontal tab.

\v

Vertical tab.

\\

A literal backslash (`\').

\NNN

The character whose ASCII code is NNN (octal).

A `\' character followed by any other character is treated as an ordinary character, so they both are printed.

%%

A literal percent sign.

%a

File's last access time in the format returned by the C `ctime' function.

%Ak

File's last access time in the format specified by k, which is either `@' or a directive for the C `strftime' function. The possible values for k are listed below; some of them might not be available on all systems, due to differences in `strftime' between systems.

@

seconds since Jan. 1, 1970, 00:00 GMT.

Time fields:

H

hour (00..23)

I

hour (01..12)

k

hour ( 0..23)

l

hour ( 1..12)

M

minute (00..59)

p

locale's AM or PM

r

time, 12-hour (hh:mm:ss [AP]M)

S

second (00..61)

T

time, 24-hour (hh:mm:ss)

X

locale's time representation (H:M:S)

Z

time zone (e.g., EDT), or nothing if no time zone is determinable

Date fields:

a

locale's abbreviated weekday name (Sun..Sat)

A

locale's full weekday name, variable length (Sunday..Saturday)

b

locale's abbreviated month name (Jan..Dec)

B

locale's full month name, variable length (January..December)

c

locale's date and time (Sat Nov 04 12:02:33 EST 1989)

d

day of month (01..31)

D

date (mm/dd/yy)

h

same as b

j

day of year (001..366)

m

month (01..12)

U

week number of year with Sunday as first day of week (00..53)

w

day of week (0..6)

W

week number of year with Monday as first day of week (00..53)

x

locale's date representation (mm/dd/yy)

y

last two digits of year (00..99)

Y

year (1970...)

%b

File's size in 512-byte blocks (rounded up).

%c

File's last status change time in the format returned by the C `ctime' function.

%Ck

File's last status change time in the format specified by k, which is the same as for %A.

%d

File's depth in the directory tree; 0 means the file is a command line argument.

%f

File's name with any leading directories removed (only the last element).

%F

Type of the filesystem the file is on; this value can be used for -fstype.

%g

File's group name, or numeric group ID if the group has no name.

%G

File's numeric group ID.

%h

Leading directories of file's name (all but the last element).

%H

Command line argument under which file was found.

%i

File's inode number (in decimal).

%k

File's size in 1K blocks (rounded up).

%l

Object of symbolic link (empty string if file is not a symbolic link).

%m

File's permission bits (in octal).

%n

Number of hard links to file.

%p

File's name.

%P

File's name with the name of the command line argument under which it was found removed.

%s

File's size in bytes.

%t

File's last modification time in the format returned by the C `ctime' function.

%Tk

File's last modification time in the format specified by k, which is the same as for %A.

%u

File's user name, or numeric user ID if the user has no name.

%U

File's numeric user ID.

A `%' character followed by any other character is discarded (but the other character is printed).

-prune

If -depth is not given, true; do not descend the current directory.
If -depth is given, false; no effect.

-ls

True; list current file in `ls -dils' format on standard output. The block counts are of 1K blocks, unless the environment variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.

OPERATORS

Listed in order of decreasing precedence:

( expr )

Force precedence.

! expr

True if expr is false.

-not expr

Same as ! expr.

expr1 expr2

And (implied); expr2 is not evaluated if expr1 is false.

expr1 -a expr2

Same as expr1 expr2.

expr1 -and expr2

Same as expr1 expr2.

expr1 -o expr2

Or; expr2 is not evaluated if expr1 is true.

expr1 -or expr2

Same as expr1 -o expr2.

expr1 , expr2

List; both expr1 and expr2 are always evaluated. The value of expr1 is discarded; the value of the list is the value of expr2.

EXAMPLES

find /home -user joe

Find every file under the directory /home owned by the user joe.

find /usr -name *stat

Find every file under the directory /usr ending in ".stat".

find /var/spool -mtime +60

Find every file under the directory /var/spool that was modified more than 60 days ago.

find /tmp -name core -type f -print | xargs /bin/rm -f

Find files named core in or below the directory /tmp and delete them. Note that this will work incorrectly if there are any filenames containing newlines, single or double quotes, or spaces.

find /tmp -name core -type f -print0 | xargs -0 /bin/rm -f

Find files named core in or below the directory /tmp and delete them, processing filenames in such a way that file or directory names containing single or double quotes, spaces or newlines are correctly handled. The -name test comes before the -type test in order to avoid having to call stat(2) on every file.

find . -type f -exec file '{}' \;

Runs `file' on every file in or below the current directory. Notice that the braces are enclosed in single quote marks to protect them from interpretation as shell script punctuation. The semicolon is similarly protected by the use of a backslash, though ';' could have been used in that case also.

find /       \( -perm -4000 -fprintf /root/suid.txt '%#m %u %p\n' \) , \
             \( -size +100M -fprintf /root/big.txt  '%-10s %p\n' \)

Traverse the filesystem just once, listing setuid files and directories into /root/suid.txt and large files into /root/big.txt.

find $HOME  -mtime 0

Search for files in your home directory which have been modified in the last twenty-four hours. This command works this way because the time since each file was last modified is divided by 24 hours and any remainder is discarded. That means that to match -mtime

0, a file will have to have a modification in the past which is less than 24 hours ago.

find . -perm 664

Search for files which have read and write permission for their owner, and group, but which other users can read but not write to. Files which meet these criteria but have other permissions bits set (for example if someone can execute the file) will not be matched.

find . -perm -664

Search for files which have read and write permission for their owner and group, and which other users can read, without regard to the presence of any extra permission bits (for example the executable bit). This will match a file which has mode 0777, for example.

find . -perm /222

Search for files which are writable by somebody (their owner, or their group, or anybody else).

find . -perm /220
find . -perm /u+w,g+w
find . -perm /u=w,g=w

All three of these commands do the same thing, but the first one uses the octal representation of the file mode, and the other two use the symbolic form. These commands all search for files which are writable by either their owner or their group. The files don't have to be writable by both the owner and group to be matched; either will do.

find . -perm -220
find . -perm -g+w,u+w

Both these commands do the same thing; search for files which are writable by both their owner and their group.

find . -perm -444 -perm /222 ! -perm /111
find . -perm -a+r -perm /a+w ! -perm /a+x

These two commands both search for files that are readable for everybody (-perm -444 or -perm -a+r), have at least on write bit set (-perm /222 or -perm /a+w) but are not executable for anybody (! -perm /111 and ! -perm /a+x respectively)

Linux geeks::::: want to FIND more... http://dsl.org/cookbook/cookbook_toc.html