fibonacci and prime testing

fibprime.sh

#!/bin/bash -

. testnum-lib.sh

LIMIT=${1:-50000}

_is_valid_number $LIMIT || {
  if [ $NAN ]; then
    echo "$LIMIT is not a positive integer"
  else
    echo "$LIMIT is not big enough"
  fi
  exit 1
}

_make_fibonacci_list

_find_fib_limit $LIMIT

_prime_fibonacci_number

numreport.sh

#!/bin/bash -

# Make a report on a given decimal. Test for prime numbers;
# if the number is not prime, factor it and print the list.
# Test for Fibonacci numbers. 

if [ $# -eq 0 ]; then
  echo "Usage: ${0##*/} number"
  exit 1
fi

. testnum-lib.sh

_is_valid_number "$1"

_is_prime_number "$1"

if [ $PRIME ]; then
  echo Prime: Yes
elif [ $NAN ]; then
  echo not a valid number
  exit 1
elif [ ! $UNFACTORABLE ]; then
  echo Prime: No
  echo Factored: "$FACT"
fi

_make_fibonacci_list
_is_fibonacci_number "$1"

if [ $FIB ]; then
  echo Fibonacci: Yes
elif [ $NAN ]; then
  echo not a valid number
else
  echo Fibonacci: No
fi

primes.sh

#!/bin/bash -

unset START STOP

while (( $# > 0 ))
do
	case $1 in
		-h*)
			break
			;;
		-[0-9]*)
			echo "not a positive integer $1"
			break
			;;
		*[!0-9]*)
			echo "invalid integer $1"
			break
			;;
		*)
			if [ $START ]
			then
				STOP=$1
			else
				START=$1
			fi
			if [ $START ] && [ $STOP ]
			then
				break
			fi
			;;
	esac
	shift
done

if (( STOP <= START ))
then
	echo "usage: ${0##*/} start stop"
	exit 1
fi

for (( i=START; i<=STOP; i++ ))
do
	num=$i
	factor=0
	for (( t=2; t<=num; t++ ))
	do
		while (( num % t == O ))
		do
			(( factor++ ))
			if (( factor > 1 ))
			then
				break 2
			else
				(( num /= t ))
			fi
		done
	done
	if (( factor == 1 ))
	then
		echo $i
	fi
done

testnum-lib.sh

#!/bin/bash

_is_valid_number()
{ # Test if a number is valid. Return failure
  # if not.

    unset UNFACTORABLE	# Zero and one cannot be factored.
    unset NAN		# At least one character is not 0-9.

    case $1 in
              0|1)
                    UNFACTORABLE=1
                    return 1
                    ;;
      *[!0-9]*|"")
                    NAN=1
                    return 1
                    ;;
    esac
}

_find_fib_limit()
{ # Given a number, count the number of Fibonacci
  # numbers closest to the number. This value is
  # loaded into the FIBLIMIT variable.

    local i c
    unset FIBLIMIT

    for i in $FIBLIST
    do
      # If the number equals a number in FIBLIST,
      # we use the index for that number.
      if [ $i -eq $1 ]; then
        FIBLIMIT=$c
        break
      # If the number is not equal but greater than
      # a number in the list, use the index number
      # of the previous number in the list. This is so
      # we don't use more numbers than we need.
      elif [ $i -gt $1 ]; then
        FIBLIMIT=$((c-1))
        break
      fi
      # Index counter. Holds the amount of Fibonacci
      # numbers to process in FIBLIST.
      ((c++))
    done
}

_is_fibonacci_number()
{ # Test if a number is a Fibonacci number. If true,
  # set FIB to 1.

    unset FIB

    for f in $FIBLIST
    do
      if [ $f -eq $1 ]; then
        FIB=1
        break
      fi
    done
}

_make_fibonacci_list()
{ # Load FIBLIST with a string of Fibonacci numbers
  # delimited by a space. The bash interpreter can only
  # generate up to the 92nd number in the sequence on a 64-bit
  # system because after that large numbers are truncated.

    unset FIBLIST
    local a=0 b=1 sum i

    for ((i=0; i<93; i++))
    do
      FIBLIST="${FIBLIST} ${a}"
      (( sum = a + b ))
      a=$b
      b=$sum
    done
}

_prime_fibonacci_number()
{ # Given a set of Fibonacci numbers, print the
  # numbers that are prime.

    local g	# Stores the Fibonacci number per loop.
    local c=0	# Count up to and stop at FIBLIMIT.
    local f	# Stores the number of factorable integers.
    local t	# Value for checking divisibility.
    local h	# Copy of g for factoring.

    for g in $FIBLIST
    do
      while (( c <= FIBLIMIT ))
      do
        h=$g
        f=0
        for (( t=2; t<=h; t++ ))
        do
          while (( h % t == O ))
          do
            ((f++))
            if (( $f > 1 )); then
              break 2
            else
              (( h /= t ))
            fi
          done
        done
        if (( $f == 1 )); then
          echo $g
        fi
        ((c++))
        break
      done
    done
}

_is_prime_number()
{
    unset PRIME FACT
    local factor=() i num=$1

    for ((i=2; i<=num; i++))
    do
      while ((num % i == O))
      do
        factor+=($i)
        ((num /= i))
      done
    done

    case ${#factor[@]} in
      1)  PRIME=1 ;;
      *)  FACT="${factor[@]}" ;;
    esac
}

_fibonacci_sequence()
{
    local a=0 b=1 sum

    for (( i=0; i<${1:-10}; i++ ))
    do
#      echo $i: $a
      echo $a
      (( sum = a + b ))
      a=$b
      b=$sum
    done
}