Is scanf's “regex” support a standard?

Question

Is scanf\'s \"regex\" support a standard? I can\'t find the answer anywhere.

This code works in gcc but not in Visual Studio:

scanf(\"%[^\\n]\",a);
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Answer 1

The "%[" format spec for scanf() is standard and has been since C90.

MSVC does support it.

You can also provide a field width in the format spec to provide safety against buffer overruns:

int main()
{
    char buf[9];

    scanf("%8[^\n]",buf);

    printf("%s\n", buf);
    printf("strlen(buf) == %u\n", strlen(buf));

    return 0;
}

Also note that the "%[" format spec doesn't mean that scanf() supports regular expressions. That particular format spec is similar to a capability of regexs (and no doubt was an influenced by regex), but it's far more limited than regular expressions.