This example obtains the information of the CONFIG.SYS file.

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

 int main(VOID) {
 UCHAR        uchFileName[80] = "C:\\CONFIG.SYS";  /* File to manipulate    */
 FILESTATUS3  fsts3ConfigInfo = {{0}};       /* Buffer for file information */
 ULONG        ulBufSize     = sizeof(FILESTATUS3);  /* Size of above buffer */
 HFILE        hfConfig      = 0;             /* Handle for Config file      */
 ULONG        ulOpenAction  = 0;             /* Action taken by DosOpen     */
 APIRET       rc            = NO_ERROR;      /* Return code                 */

  rc = DosOpen(uchFileName,                 /* File to open (path and name) */
               &hfConfig,                /* File handle returned         */
               &ulOpenAction,               /* Action taken by DosOpen      */
               0L,0L,        /* Primary allocation and attributes (ignored) */
               OPEN_ACTION_FAIL_IF_NEW |
               OPEN_ACTION_OPEN_IF_EXISTS,  /* Open an existing file only   */
               OPEN_FLAGS_NOINHERIT | OPEN_ACCESS_READONLY |
               OPEN_SHARE_DENYNONE,         /* Read access only             */
               0L);                         /* Extended attributes (ignored)*/

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

    rc = DosQueryFileInfo(hfConfig,   /* Handle of file                  */
                          FIL_STANDARD,  /* Request standard (Level 1) info */
                          &fsts3ConfigInfo, /* Buffer for file information  */
                          ulBufSize);    /* Size of buffer                  */
    if (rc != NO_ERROR) {
        printf("DosQueryFileInfo error: return code = %u\n", rc);
        return 1;
    }

    rc = DosClose(hfConfig);      /* Close the file  (check RC in real life) */
    printf("%s ---  File size: %u bytes\n",uchFileName, fsts3ConfigInfo.cbFile);
    printf("Last updated: %d/%d/%d; %d:%2.2d\n",
            fsts3ConfigInfo.fdateLastWrite.month,        /* Month            */
            fsts3ConfigInfo.fdateLastWrite.day,          /* Day              */
            (fsts3ConfigInfo.fdateLastWrite.year+1980L), /* Years since 1980 */
            fsts3ConfigInfo.ftimeLastWrite.hours,        /* Hours            */
            fsts3ConfigInfo.ftimeLastWrite.minutes);     /* Minutes          */

  return NO_ERROR;
}