replace.cpp: In function `int main()': replace.cpp:14: warning: assignment to non-pointer type `char' from NULL replace.cpp:14: warning: argument to non-pointer type `char' from NULL replace.cpp:30: warning: assignment to non-pointer type `char' from NULL replace.cpp:30: warning: argument to non-pointer type `char' from NULL /tmp/ccIuyFVL.o(.text+0x79): In function `main': : the `gets' function is dangerous and should not be used.