foo.c: In function 'main':
foo.c:11:9: warning: implicit declaration of function 'scanf_s'; did you mean 'scanf'? [-Wimplicit-function-declaration]
   11 |         scanf_s("%s", &str, 100);
      |         ^~~~~~~
      |         scanf
foo.c:9:13: warning: unused variable 'length' [-Wunused-variable]
    9 |         int length;
      |             ^~~~~~
/nix/store/j2gmfdd29cp3rcvghmn1a5kgcnmf8myp-binutils-2.40/bin/ld: /tmp/ccG6L6v0.o: in function `main':
foo.c:(.text.startup+0x6d): undefined reference to `scanf_s'
collect2: error: ld returned 1 exit status

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