Purpose

DosQueryFileInfo gets file information.

Syntax

#define INCL DOSFILEMGR
#include  os2.h 

APIRET DosQueryFileInfo

(HFILE hf, ULONG ulInfoLevel, PVOID pInfo, ULONG cbInfoBuf)

Parameters

hf HFILE) input

The file handle.
ulInfoLevel ULONG) input
Level of file information required.

Specify a value

• FIL_STANDARD

  Level 1 file information

  11

  FIL_STANDARDL

  Level 11 file information

  2
  FIL_QUERYEASIZE

  Level 2 file information

  12
  FIL_QUERYEASIZEL

  Level 12 file information

  3
  FIL_QUERYEASFROMLIST

  Level 3 file information

  Level 4 is reserved.

  The structures described in pInfo indicate the information returned for each of these levels.

pInfo PVOID) output
Address of the storage area where the system returns the requested level of file information.

File information, where applicable, is at least as accurate as the most recent DosClose, DosResetBuffer, DosSetFileInfo, or DosSetPathInfo.

Level 1 File Information (ulInfoLevel == FIL_STANDARD)

pInfo contains the FILESTATUS3 data structure, in which file information is returned.
Level 11 File Information (ulInfoLevel == FIL_STANDARDL)
pInfo contains the FILESTATUS3L data structure, in which file information is returned.
Level 2 File Information (ulInfoLevel == FIL_QUERYEASIZE)
pInfo contains the FILESTATUS4 data structure. This is similar to the Level 1 structure, with the addition of the cbList field after the attrFile field.

The cbList field is an unsigned ULONG. On output, this field contains the size, in bytes, of the file s entire extended attribute (EA) set on disk. You can use this value to calculate the size of the buffer required to hold the EA information returned when a value of 3 is specified for ulInfoLevel. The buffer size is less than or equal to twice the size of the file s entire EA set on disk.

Level 12 File Information (ulInfoLevel == FIL_QUERYEASIZEL)
pInfo contains the FILESTATUS4L data structure. This is similar to the Level 1 structure, with the addition of the cbList field after the attrFile field.

The cbList field is an unsigned ULONG. On output, this field contains the size, in bytes, of the file s entire extended attribute (EA) set on disk. You can use this value to calculate the size of the buffer required to hold the EA information returned when a value of 3 is specified for ulInfoLevel. The buffer size is less than or equal to twice the size of the file s entire EA set on disk.

Level 3 File Information (ulInfoLevel == FIL_QUERYEASFROMLIST)

Input

pInfo contains an EAOP2 data structure. fpGEA2List points to a GEA2 list defining the attribute names whose values are returned. The GEA2 data structures must be aligned on a doubleword boundary. Each oNextEntryOffset field must contain the number of bytes from the beginning of the current entry to the beginning of the next entry in the GEA2 list. The oNextEntryOffset field in the last entry of the GEA2 list must be 0. fpFEA2List points to a data area where the relevant FEA2 list is returned. The length field of this FEA2 list is valid, giving the size of the FEA2 list buffer. oError is ignored.
Output
pInfo is unchanged. The buffer pointed to by fpFEA2List is filled with the returned information. If the buffer that fpFEA2List points to is not large enough to hold the returned information (the return code is ERROR_BUFFER_OVERFLOW), cbList is still valid, assuming there is at least enough space for it. Its value is the size of the entire EA set on disk for the file, even though only a subset of attributes was requested.
cbInfoBuf ULONG) input
The length, in bytes, of pInfo.

Returns

ulrc APIRET) returns

Return Code.

DosQueryFileInfo returns one of the following values

• NO_ERROR

• ERROR_ACCESS_DENIED

• ERROR_INVALID_HANDLE

  111

  ERROR_BUFFER_OVERFLOW
  124
  ERROR_INVALID_LEVEL
  130
  ERROR_DIRECT_ACCESS_HANDLE
  254
  ERROR_INVALID_EA_NAME
  255
  ERROR_EA_LIST_INCONSISTENT

  Remarks

  Information levels designated L should be used in order to get complete size information for files larger than 2GB. If information levels designated L are not used, a size of one byte will be returned for files which are >2GB in size.

  In the FAT file system, only date and time information contained in Level 1 file information can be modified. Zero is returned for the creation and access dates and times.

  To return information contained in any of the file information levels, DosQueryFileInfo must be able to read the open file. DosQueryFileInfo works only when the file is opened for read access, with a deny-write sharing mode specified for access by other processes. If another process that has specified conflicting sharing and access modes has already opened the file, any call to DosOpenL will fail.

  DosEnumAttribute returns the lengths of EAs. This information can be used to calculate what size pInfo needs to be to hold full-extended-attribute (FEA) information returned by DosQueryFileInfo when Level 3 is specified. The size of the buffer is calculated as follows

  Four bytes (for oNextEntryOffset) + One byte (for fEA +
  One byte (for cbName) +
  Two bytes (for cbValue) +
  Value of cbName (for the name of the EA) +
  One byte (for terminating NULL in cbName) +
  Value of cbValue (for the value of the EA)

  Related Functions

  • DosClose

  • DosEnumAttribute

  • DosOpen

  • DosOpenL

  • DosQueryPathInfo

  • DosResetBuffer

  • DosSetFileInfo

  • DosSetFileSize

  • DosSetFileSizeL

  • DosSetPathInfo

  Example Code

  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    */
  FILESTATUS3L  fsts3ConfigInfo =   0  ;       /* Buffer for file information */
  ULONG        ulBufSize     = sizeof(FILESTATUS3L);  /* Size of above buffer */
  HFILE        hfConfig      = 0;             /* Handle for Config file      */
  ULONG        ulOpenAction  = 0;             /* Action taken by DosOpenL     */
  APIRET       rc            = NO_ERROR;      /* Return code                 */
  
  rc = DosOpenL(uchFileName,                 /* File to open (path and name) */
   hfConfig,                /* File handle returned         */
   ulOpenAction,               /* Action taken by DosOpenL      */
  (LONGLONG)0,0L,        /* 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("DosOpenL error  return code = %u\n", rc);
  return 1;
   
  
  rc = DosQueryFileInfo(hfConfig,   /* Handle of file                  */
  FIL_STANDARDL,  /* Request standard (Level 11) 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  %lld 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;
   
  

  ---

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