sizeof argv[1] not working

Question

I\'m really new to C and all I know is that the error is related to oldname and newname not be initialized

#include 

in         


        

Answer 1

sizeof() returns the size of the type - ie the size of a pointer (probably 32bits) or a char (8bits)
To get the length of a string you need strlen()

Additionally in ansi C you can't create an array with a variable for the size. You can in the new C standard or for now you can use malloc() to create an array