C 更改檔名 example

紀錄C當中，一個簡單的改檔名function，rename();

#include <stdio.h>

int main () {
   int ret;
   char oldname[] = "file.txt";
   char newname[] = "newfile.txt";
 
   ret = rename(oldname, newname);

   if(ret == 0) {
      printf("renamed successfully");
   } else {
      printf("unable to rename");
   }
 
   return 0;
}