/in/foo.c:2:5: warning: conflicting types for built-in function 'strlen'
int strlen(char *s){
^~~~~~
/in/foo.c: In function 'main':
/in/foo.c:9:2: warning: 'gets' is deprecated [-Wdeprecated-declarations]
gets(a);
^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
extern char *gets (char *__s) __wur __attribute_deprecated__;
^~~~
/in/foo.c:10:9: warning: 'gets' is deprecated [-Wdeprecated-declarations]
gets(b);
^~~~
In file included from /in/foo.c:1:0:
/usr/include/stdio.h:640:14: note: declared here
extern char *gets (char *__s) __wur __attribute_deprecated__;
^~~~
/tmp/ccGTJGWs.o: In function `main':
foo.c:(.text.startup+0xb): warning: the `gets' function is dangerous and should not be used.