This example creates a backup copy of the file "CONFIG.SYS" with the new name "CONFIG.CPY", in the root directory, even if the new file name already exists.

 #define INCL_DOSFILEMGR   /* File Manager values */
 #define INCL_DOSERRORS    /* DOS error values    */
 #include <os2.h>
 #include <stdio.h>
 #include <string.h>

int main(VOID) {
   UCHAR   achSourceString[80]  = "config.sys";  /* String to transform */
   UCHAR   achEditString[80]    = "*.cpy";       /* Editing string */
   UCHAR   achTargetString[200] = "";            /* Destination string buffer */
   APIRET  rc                   = NO_ERROR;      /* Return code */

   rc = DosSetDefaultDisk(3);    /* Set drive to C: (1=A, 2=B, 3=C, ...)      */
   if (rc != NO_ERROR) {
      printf("DosSetDefaultDisk error: return code = %u\n", rc);
      return 1;
   }

   rc = DosSetCurrentDir ("\\");  /*  Set directory to root */
   if (rc != NO_ERROR) {
      printf("DosSetCurrentDir error: return code = %u\n", rc);
      return 1;
   }

           /* Transform "CONFIG.SYS" using "*.CPY" to "CONFIG.CPY" */

   rc = DosEditName(1, achSourceString, achEditString, achTargetString, 200);

   if (rc != NO_ERROR) {
      printf("DosEditName error: return code = %u\n", rc);
      return 1;
   }

           /* Copy contents of CONFIG.SYS to the backup file */

   rc = DosCopy(achSourceString,             /* Name of file to be copied    */
                achTargetString,             /* Name of the target file      */
                DCPY_EXISTING);   /* Copy even if target file already exists */

   if (rc != NO_ERROR) {
      printf("DosCopy error: return code = %u\n", rc);
      return 1;
   } else  printf ("Backup file %s created.\n", achTargetString);
   return NO_ERROR;
}