Bash script error: [i: command not found

Question

This program is suppose to accept a number from the user and print that many prime numbers. For some reason the program doesn\'t work. I am new to bash scripting and this is my

Answer 1

#!/bin/bash
#
# primes
#
read -p "Enter a  number: " n
i=2

for (( i=2; i <= n; i++ ))
do
    for (( j=2; j*j < i; j++ ))
    do
        if ((i % j == 0))
        then
            echo "no prime, $i divider: "$j
            break
        fi
    done
done

updated, after realizing (thanks Will Ness), that all primes up to INPUT are searched.

i needs to run to √(n) only.

Answer 2

if [i % j == 0]; Should be if [ i % j == 0 ];

Same for the one on line 18

Answer 3

You need to place a space after the [ because [ is an application.

And you can't make calculations between the brackets. You will need to tell bash it needs to calculate the values. So you would need to change line 11 to if (( i % j == 0 )).

Answer 4

Like the others have said, the [ program needs a space before its parameters, like all programs need a space before their args. This is one reason why I prefer the test builtin to [ with its kludgy syntax requiring a useless ] as the last arg just to make it look pretty and sane.

if test $((i % j)) = 0; then
   break
fi