foo.c: In function 'main':
foo.c:20:17: warning: implicit declaration of function 'getcahr'; did you mean 'getchar'? [-Wimplicit-function-declaration]
   20 |                 getcahr();
      |                 ^~~~~~~
      |                 getchar
foo.c: In function 'daoxu':
foo.c:10:1: warning: control reaches end of non-void function [-Wreturn-type]
   10 | }
      | ^
/nix/store/3r87a2wq1w4l66wnsm7rqvy608mx23h6-binutils-2.40/bin/ld: /tmp/ccoKTCMl.o: in function `main':
foo.c:(.text.startup+0x57): undefined reference to `getcahr'
collect2: error: ld returned 1 exit status

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