foo.c: In function 'main':
foo.c:14:17: warning: implicit declaration of function 'strcat_s'; did you mean 'strcat'? [-Wimplicit-function-declaration]
   14 |                 strcat_s(b, a);
      |                 ^~~~~~~~
      |                 strcat
foo.c:10:13: warning: unused variable 'c' [-Wunused-variable]
   10 |         int c = getchar();
      |             ^
/nix/store/3r87a2wq1w4l66wnsm7rqvy608mx23h6-binutils-2.40/bin/ld: /tmp/ccnlkC2S.o: in function `main':
foo.c:(.text.startup+0x60): undefined reference to `strcat_s'
/nix/store/3r87a2wq1w4l66wnsm7rqvy608mx23h6-binutils-2.40/bin/ld: foo.c:(.text.startup+0x71): undefined reference to `strcat_s'
collect2: error: ld returned 1 exit status

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