Shell Programming and Scripting

Fibonacci (){
  case $1 in
    0|1) printf "$1 " ;;
    *)   printf "$(( $(Fibonacci $(($1-2))) + $(Fibonacci $(($1-1))) )) ";;
  esac
}

i=0
while [ $i -lt $1 ]
do
  i=$((i+1))
  Fibonacci $i
done
echo

$ time ./testzsh 10
1 1 2 3 5 8 13 21 34 55

real    0m0.837s
user    0m0.180s
sys     0m0.648s
$ time ./testbash 10
1 1 2 3 5 8 13 21 34 55

real    0m0.887s
user    0m0.300s
sys     0m0.580s
$ time ./testdash 10
1 1 2 3 5 8 13 21 34 55

real    0m0.292s
user    0m0.048s
sys     0m0.240s
$ time ./testksh 10
1 1 2 3 5 8 13 21 34 55

real    0m0.092s
user    0m0.088s
sys     0m0.000s

$ time ./nonrecurs 10
0 1 1 2 3 5 8 13 21 34 55

real    0m0.013s
user    0m0.016s
sys     0m0.000s

#!/bin/sh
fibonnacci()
{
        case $n in
                0) echo 0;      return;;
                1) echo 0 1;    return;;
                *) echo -n 0 1
                                a=0; b=1; c=2;
                                while [ $c -le $n ]
                                do
                                        t=$(( a + b ))
                                        echo -n " $t"
                                        a=$b; b=$t;
                                        c=$(( c + 1 ))
                                done
                                echo
                                return;;
        esac
}
#
n=${1:-10}
if [ ! `expr $n + 1 2> /dev/null` ] ; then
        echo "Value of the arguments < $n > IS NOT an integer!"
        exit 1
fi
echo "Fibonnacci series for value $n is:"
fibonnacci $n
exit 0

x=`expr $x - 1`

(( x = x - 1 ))

#!/bin/ksh

fibonacci ()
{
typeset -i iStopAt=$1
typeset -i iFibLast1=1
typeset -i iFibLast2=0
typeset -i iFibCurrent=1
typeset -i iCurrIndex=1

while [ $iCurrIndex -le $iStopAt ] ; do
     (( iFibCurrent = iFibLast1 + iFibLast2 ))
     iFibLast2=iFibLast1
     iFibLast1=iFibCurrent
     (( iCurrIndex += 1 ))
done

print - "$iFibCurrent"
return 0
}

# main ()
iCnt=1

while [ iCnt -le 25 ] ; do
     fibonacci $iCnt
     (( iCnt += 1 ))
done
exit 0

#!/bin/ksh

Fibonacci (){
  for (( i=0; i<=$1; i++ )); do
    case $i in
      0|1) val=$i ;;
      *)   val=$((val1 + val2));;
    esac
    printf "$val "
    val2=$val1
    val1=$val
  done
}

Fibonacci $1
echo