Write a shell program to generate the first hundred numbers in the Fibonacci series?

Answer 1

bin

echo "Enter How many numbers:"

read 100

num1=0

num2=1

echo "Fibonacci series:"

echo $num1

echo $num2

count=2

while [ $count -le $num ]

do

num3=`expr $num1 + $num2`

echo $num3

num1=$num2

num2=$num3

count=`expr $count + 1`

done

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ANSWER:

The above script didn't work at all for me so I wrote this one. That said, the author of the script above appears to be familiar with the subject matter and the challenges involved, but was possibly busy or distracted at the time the answer was written.

NOTE: One obvious omission is the lack of an absolute PATH for the 'shebang' line of the script, it is this which leads me suspect his or her

mind may not have been on the task at hand when the script was written. I believe the author above is experienced at script writing however.

#!/bin/bash

#

## Written by John Horn, June, 2013.

#

# set -x

if [ -z ${1} ]; then

echo "Pass the number of fibonacci numbers you wish generated as the argument to this script."

exit

fi

#

## Decided to add comma insertion every 3rd digit to make the

## output easier to read. Friday the 13th of September, 2013.

## Friday the 13th? That isn't very auspicious. :(

#

## This subroutine inserts a comma every 3rd digit to the arg passed.

#

commify () {

typeset text=${1}

typeset bdot=${text%%.*}

typeset adot=${text#${bdot}}

typeset i commified

(( i = ${#bdot} - 1 ))

while (( i>=3 )) && [[ ${bdot:i-3:1} == [0-9] ]]; do

commified=",${bdot:i-2:3}${commified}"

(( i -= 3))

done

echo "${bdot:0:i+1}${commified}${adot}"

}

#

## Initialize some variables for whatever reason (simplicity maybe).

#

LIMIT=${1}

COUNT=0

N1=0

N2=1

FIBONACCI=0

#

## Might as well just print the first two as they can't possibly

## have any other value than 0 and 1.

#

echo "And our first ${LIMIT} FIBONACCI numbers are...:"

echo "0"

echo "1"

while [ ${COUNT} -le ${LIMIT} ]; do

#

## Fork the 'bc' command to perform the actual addition operation.

#

FIBONACCI=`echo "${N1} + ${N2}"|bc -l`

#

## Call the commify() subroutine to format the integer with commas.

#

COMMA_FORMATTED_RESULT=`commify "${FIBONACCI}"`

#

## Print our latest FIBONACCI number to STDOUT.

#

echo "${COMMA_FORMATTED_RESULT}"

#

## Overwrite our variable contents with our new values.

#

N1=${N2}

N2=${FIBONACCI}

#

## Increment our counter so we'll know when we've reached our $LIMIT.

#

(( COUNT++ ))

done

echo -e "\n\nAll done.\n"

----------------------------

On my Ubuntu Linux 12.04 LTS machine the above script works perfectly. Your

mileage may vary. Good luck!

JMH