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"&" Malfunctioning in terminal

I started with PWK and I am stuck at a bash script session.The following code works for me:

#!/bin/bash
for var in $(cat wordlist.txt); do
host $url.megacorpone.com &
done

What this does as told in the lecture is the use of "&" symbol, i.e. the background scanning while one instance has been created and it works correctly.

But, when I try the command line:

for url in $(cat wordlist.txt); do host $var.megacorpone.com &;done;

it gives me a junk output, then shows : 0xarjun@localhost: and when I press enter, shows the result of previous command. What in the world is happening?

Solution

  • From bash man page:

    A list is a sequence of one or more pipelines separated by one of the operators ;, &, &&, or ||, and optionally terminated by one of ;, &, or <newline>.

    Remove the sequential operator ; right after the background operator &, as both are not allowed together in bash.