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Full Discussion: Generate Random Password in C
Top Forums Programming Generate Random Password in C Post 302203705 by jim mcnamara on Monday 9th of June 2008 02:52:53 PM
Old 06-09-2008
Here is a simple algorithm:
Code:
#include <stdlib.h>
#include <time.h>

static int srand_called=0;

char *random_pw(char *dest)
{
    size_t len=0;
    char *p=dest;
    int three_in_a_row=0;
    int arr[128]={0x0};

	/* be sure to have called srand exactly one time */
	if(!srand_called)
	{
		srandom(time(NULL));
		srand_called=1;
	}
	*dest=0x0; /* int the destination string*/
	for(len=6 + rand()%3; len; len--, p++) /* gen characters */
	{
		char *q=dest;
		*p=(rand()%2)? rand()%26 + 97: rand()%10 + 48;
		p[1]=0x0;
		arr[*p]++;                         /* check values */
		if(arr[*p]==3)
		{
			for(q=dest; q[2]>0 && !three_in_a_row; q++)	
				if(*q==q[1] && q[1]==q[2])
			   		three_in_a_row=1;
		}
		if(three_in_a_row || arr[*p]> 3 )
			return random_pw(dest);        /* values do not pass try again */
	}
    return dest;
}

Last edited by jim mcnamara; 06-11-2008 at 05:59 PM.. Reason: change srand to srandom
 

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LEARN ABOUT DEBIAN

www::mechanize::formfiller::value::random::chars

WWW::Mechanize::FormFiller::Value::Random::Chars(3pm)	User Contributed Perl Documentation  WWW::Mechanize::FormFiller::Value::Random::Chars(3pm)

NAME

       WWW::Mechanize::FormFiller::Value::Random::Chars - Fill characters into an HTML form field

SYNOPSIS

	 use WWW::Mechanize::FormFiller;
	 use WWW::Mechanize::FormFiller::Value::Random::Chars;

	 my $f = WWW::Mechanize::FormFiller->new();

	 # Create a random value for the HTML field "login"

	 my $login = WWW::Mechanize::FormFiller::Value::Random::Chars->new(
			      login => set => 'alpha', min => 3, max => 8 );
	 $f->add_value( login => $login );

	 # Alternatively take the following shorthand, which adds the
	 # field to the list as well :

	 # If there is no password, put a random one out of the list there
	 my $password = $f->add_filler( password => 'Random::Chars' );

DESCRIPTION

       This class provides a way to write a randomly chosen value into a HTML field.

       new NAME, LIST
	   Creates a new value which will correspond to the HTML field "NAME". The "LIST" is the list of arguments passed to
	   Data::Random::rand_chars. If the list is empty, "set => 'alpha', min => 5, max => 8" is assumed.

       name [NEWNAME]
	   Gets and sets the name of the HTML field this value corresponds to.

       value FIELD
	   Returns the value to put into the HTML field.

   EXPORT
       None by default.

   COPYRIGHT AND LICENSE
       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

       Copyright (C) 2002,2003 Max Maischein

AUTHOR

       Max Maischein, <corion@cpan.org>

       Please contact me if you find bugs or otherwise improve the module. More tests are also very welcome !

SEE ALSO

       Data::Random, WWW::Mechanize, WWW::Mechanize::Shell, WWW::Mechanize::FormFiller, WWW::Mechanize::FormFiller::Value::Value,
       WWW::Mechanize::FormFiller::Value::Default, WWW::Mechanize::FormFiller::Value::Fixed, WWW::Mechanize::FormFiller::Value::Interactive

perl v5.10.1							    2009-04-24		     WWW::Mechanize::FormFiller::Value::Random::Chars(3pm)
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