Shell Script To Produce Prime Numbers Within A Range

#!/bin/bash
# SCRIPT: primenumbers.sh
# USAGE : ./primenumbers.sh <Range Value>
#                      or;
#         ./ primenumbers.sh <Start Range Value> <End Range Value>
# PURPOSE: Produce prime numbers within a range lmit.

############### DEFINE FUNCTIONS HERE ##############

Usage()
{
    echo "********BAD ARGUMENTS**********"
    echo "Usage: scriptname <Range Value >"
    echo "               or                   "
    echo "Usage: scriptname <Start Range Value> <End Range Value>"
    exit 1
}

################# ARGUMENTS CHECKING #################

[ $# -gt 2 -o $# -lt 1 ] && Usage
[ $# -eq 1 ] && Bnum=2 &&  Enum=$1
[ $# -eq 2 ] && Bnum=$1  Enum=$2 && [ $1 -gt $2 ] && Usage
[ $1 -lt 2 ] && Bnum=2

############### MAIN PROGRAM STARTS HERE #############

count=1

while [ $Bnum -le $Enum ]
do
num=$Bnum
Prime="yes"
i=1

#while [ $i -lt $((num/2)) ]
while [ $((i*i)) -lt $((num-1)) ]
do
  let i++
  if [ $((num%i)) -eq 0 ]          # you can also use `expr $num % $i`
  then
      Prime="no"
      break
  fi
done

[ "$Prime" = "yes" ] && printf "%5d " $num && let count++

# count is used to print 10 values in a row

[ $count -eq 11 ] && count=1 &&  echo
let Bnum++
done
echo

OUTPUT:

$ ./primenumbers.sh 1 350
    2     3     5     7    11    13    17    19    23    29 
   31    37    41    43    47    53    59    61    67    71 
   73    79    83    89    97   101   103   107   109   113 
  127   131   137   139   149   151   157   163   167   173 
  179   181   191   193   197   199   211   223   227   229 
  233   239   241   251   257   263   269   271   277   281 
  283   293   307   311   313   317   331   337   347   349 

$ ./primenumbers.sh 1900 2500
 1901  1907  1913  1931  1933  1949  1951  1973  1979  1987 
 1993  1997  1999  2003  2011  2017  2027  2029  2039  2053 
 2063  2069  2081  2083  2087  2089  2099  2111  2113  2129 
 2131  2137  2141  2143  2153  2161  2179  2203  2207  2213 
 2221  2237  2239  2243  2251  2267  2269  2273  2281  2287 
 2293  2297  2309  2311  2333  2339  2341  2347  2351  2357 
 2371  2377  2381  2383  2389  2393  2399  2411  2417  2423 
 2437  2441  2447  2459  2467  2473  2477 

$ ./primenumbers.sh 200
    2     3     5     7    11    13    17    19    23    29 
   31    37    41    43    47    53    59    61    67    71 
   73    79    83    89    97   101   103   107   109   113 
  127   131   137   139   149   151   157   163   167   173 
  179   181   191   193   197   199 

[root@localhost shell]# ./primenumbers.sh 200 100
********BAD ARGUMENTS**********
Usage: scriptname <Range Value>
               or                   
Usage: scriptname <Start Range Value> <End Range Value>

NOTE:
this script can't find the highest prime number,but it can figure out the highest prime number your system is capable of calculating.