Bash Read Lines Into Multiple Variables

What's the difference between <<, <<< and < < in bash? Here document << is known as here-document structure. You let the program know what will be the ending text, and whenever that delimiter is seen, the program will read all the stuff you've given to the program as input and perform a task upon it. Here's what I mean: $ wc << EOF > one two three > four five > EOF 2 5 24 In this example we ...

In Bash, there appear to be several variables which hold special, consistently-meaning values. For instance, ./myprogram &; echo $! will return the PID of the process which backgrounded myprog...

bash - What are the special dollar sign shell variables ... - Stack ...

bash - What is the purpose of "&&" in a shell command? - Stack Overflow

What is the operator =~ called? I'm not sure it has a name. The bash documentation just calls it the =~ operator. Is it only used to compare the right side against the left side? The right side is considered an extended regular expression. If the left side matches, the operator returns 0, and 1 otherwise. Why are double square brackets required when running a test? Because =~ is an operator of ...

For understanding bash code it is usually very helpful to set the -x option: set -x # within a script / function or when calling a script: bash -vx ./script.sh With loops this is a little less helpful. But you can always take the first part of the command and do this: echo for url in $(cat example.txt) That shows you what happens there (at least the result). This feature is called "command ...

bash - What does $ ( ... ) mean in the shell? - Unix & Linux Stack Exchange

Furthermore, when you use bash -c, behavior is different than if you run an executable shell script, because in the latter case the argument with index 0 is the shell command used to invoke it. As such, I think the way to fix this answer is to change it to execute scripts as files instead of using bash -c, since that's how the asker was doing it.