foo.c: In function 'main':
foo.c:5:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
    5 |         gets(s);
      |         ^~~~
In file included from foo.c:1:
/nix/store/y8wfrgk7br5rfz4221lfb9v8w3n0cnyd-glibc-2.37-8-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
foo.c:6:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
    6 |         gets(s1);
      |         ^~~~
/nix/store/y8wfrgk7br5rfz4221lfb9v8w3n0cnyd-glibc-2.37-8-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
foo.c:7:20: warning: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
    7 |         int len1 = strlen(s);
      |                    ^~~~~~
foo.c:2:1: note: include '<string.h>' or provide a declaration of 'strlen'
    1 | #include <stdio.h>
  +++ |+#include <string.h>
    2 | int main()
foo.c:7:20: warning: incompatible implicit declaration of built-in function 'strlen' [-Wbuiltin-declaration-mismatch]
    7 |         int len1 = strlen(s);
      |                    ^~~~~~
foo.c:7:20: note: include '<string.h>' or provide a declaration of 'strlen'
/nix/store/74y3751gsixaz9797ib0hp7c658sp1y5-binutils-2.40/bin/ld: /tmp/cc6eLNYZ.o: in function `main':
foo.c:(.text.startup+0xf): warning: the `gets' function is dangerous and should not be used.

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