CODEWITHSUNDEEP
bash
Switchkick
Switchkick

Reputation: 2796

Variables not passing to a command

I am wondering why the variables ($HOST and $i) are not being passed to the timeout 1 bash -c 'cat < /dev/null > /dev/tcp/$HOST/$i' && echo $? command.

#!/bin/bash

HOST=$1

for i in {0..8889}
do
    OPENPORT=$(timeout 1 bash -c 'cat < /dev/null > /dev/tcp/$HOST/$i' && echo $?)
    if [ "$OPENPORT" == 0 ]
    then
        echo -e "Port $i is open on $HOST.\n"
    fi
done

Upvotes: 0

Views: 51

Answers (1)

Suku
Suku

Reputation: 3880

Its because your variables are in single quotes ('). Use double quotes (") instead.

From gnu.org

Enclosing characters in single quotes (') preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash.

Upvotes: 2

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