shellcheck

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This & terminates the command. Escape it or add space after & to silence.

Problematic code:
Correct code:
Rationale:
Exceptions:
Related resources:

This `&` terminates the command. Escape it or add space after `&` to silence.

Problematic code:

curl https://www.google.com/search?q=cats&tbm=isch

Correct code:

curl "https://www.google.com/search?q=cats&tbm=isch"

Rationale:

An unescaped and unquoted & terminates the command, but here it's used in the middle of what would otherwise be a shell word. This most commonly happens when copying a URL with query string parameters without escaping the &.

Either quote or escape the & if you wanted it as a literal ampersand, or add a space after it to make it easier to see where the previous command stopped.

Exceptions:

If you do want to background one command and run another, e.g. sleep 10&wait, just add a space or linefeed after the & to make this more obvious: sleep 10& wait

This does not change the meaning of the script, it just makes it clear to ShellCheck (and other humans) that the & isn't supposed to be a part of the shell world.

Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!

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Each individual ShellCheck warning has its own wiki page like SC1000. Use GitHub Wiki's "Pages" feature above to find a specific one, or see Checks.

This & terminates the command. Escape it or add space after & to silence.

Problematic code:

Correct code:

Rationale:

Exceptions:

Related resources:

This `&` terminates the command. Escape it or add space after `&` to silence.