UNIX for Dummies Questions & Answers

(03:08:02\[D@DeCoBox15)
[~]$ cat fib
#!/usr/bin/bash				

ret ()
{
        echo -ne "\n"
        sleep .5
}


a=1
b=2
echo -n $a      #1      A
ret
echo -n $b      #2      B
ret

while true
do
        c=$(($a+$b))
        echo -n $c      #3      C
        ret
        a=$(($c+$b))
        echo -ne $a     #5      A
        ret
        b=$(($c+$a))
        echo -ne $b     #8      B
        ret
done

(03:05:20\[D@DeCoBox15)
[~]$ ./fib|head -15|nl
     1  1
     2  2
     3  3
     4  5
     5  8
     6  13
     7  21
     8  34
     9  55
    10  89
    11  144
    12  233
    13  377
    14  610
    15  987

(03:05:05\[D@DeCoBox15)
[~]$ ./fib|head -92|nl|tail -1
    92  -6246583658587674878

#!/usr/bin/perl

#--------------------------------------------------------------------#
#Fibonacci Generator
#       Date Written:   22-Jul-2001 10:12:09 AM
#       Last Modified:  13-Aug-2001 10:06:30 AM
#       Author:         Kurt Kincaid
#
#       This is free software and may be redistributed under the
#       same terms as Perl itself.
#--------------------------------------------------------------------#

use Getopt::Std;
use Math::BigInt;

$| = 1;
$VERSION = "1.2";
$x = Math::BigInt->new(1);
$y = Math::BigInt->new(2);

getopts("ch");

$\= $opt_c ? "\n" : " ";

if ( $opt_h ) {
    print <<END;
Fibonacci Generator v$VERSION
Usage: $0 [-ch] [number]
-c\tPrint output in a single column (default is rows)
-h\tPrint help text (what you're reading now)

    Include how many numbers in the sequence you want, 
    otherwise it defaults to 100.
END
    exit;
}

my $stop = shift || 100;

print "$x\n";
print "$y\n";

for ( 3 .. $stop ) {
    ( $x, $y ) = ( $y, $x+$y );
    print "$y\n";

}

 92  1.220017e+19

> getconf LONG_MAX
2147483647

$ echo $((2147483647*2147483647))
4611686014132420609
$ bash --version
GNU bash, version 4.0.35(2)-release (i686-pc-linux-gnu)
Copyright (C) 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.