man curl says:

-S, --show-error

When used with -s it makes curl show an error message if it fails.

If curl -S (uppercase) will show error instead an alleged default silent mode, then I don't understand the man further description about curl -s (lowercase) and especially I don't understand something like curl -sS.

What is curl -sS?

1 Answer 1


Same as: curl --silent --show-error

The man page is trying to tell you that these options are to be used together. This means

Run curl in silent mode, and show no output unless there is an error.

Note that S cannot be used with any other options, and s can be used without S. These options are most useful in shell scripting.

Example: (Pseudo Code)

do while displayInputPrompt

curl -sS http://www.example.com/path/to/some/tar/file/file.tar.bz2

In the example, notice that the user won't see any output during the data fetch. The user will only see the input prompt displayed in the displayInputPrompt function, unless there is an error, in which curl will print the error to stdout i.e. your screen.

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