/in/HW5.c: In function 'strshift':
/in/HW5.c:20:12: error: function returns address of local variable [-Werror=return-local-addr]
     return str;
            ^~~
/in/HW5.c:15:10: note: declared here
     char str1[256]="\0";
          ^~~~
cc1: all warnings being treated as errors