foo.c: In function 'Concat':
foo.c:6:9: warning: unused variable 'len2' [-Wunused-variable]
    6 |     int len2 = strlen(str2);
      |         ^~~~
foo.c: In function 'main':
foo.c:18:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
   18 |         gets(s1);
      |         ^~~~
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:19:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
   19 |         gets(s2);
      |         ^~~~
/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: In function 'Concat':
foo.c:9:5: warning: 'strncpy' specified bound depends on the length of the source argument [-Wstringop-truncation]
    9 |     strncpy(dest, str1, len1 - 1);
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:5:16: note: length computed here
    5 |     int len1 = strlen(str1);
      |                ^~~~~~~~~~~~
/nix/store/74y3751gsixaz9797ib0hp7c658sp1y5-binutils-2.40/bin/ld: /tmp/ccI0jOM3.o: in function `main':
foo.c:(.text.startup+0xb): warning: the `gets' function is dangerous and should not be used.

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