DosSetFileSizeL: Difference between revisions

Latest revision as of 16:23, 29 November 2018

DosSetFileSizeL changes the size of a file.

Syntax

DosSetFileSizeL (hFile, cbSize)

Parameters

hFile (HFILE) input: The handle of the file whose size to be changed.
cbSize (LONGLONG) input: The new size, in bytes, of the file.

Return Code

ulrc (APIRET) returns: DosSetFileSizeL returns one of the following values:

0 NO_ERROR
5 ERROR_ACCESS_DENIED
6 ERROR_INVALID_HANDLE
26 ERROR_NOT_DOS_DISK
33 ERROR_LOCK_VIOLATION
87 ERROR_INVALID_PARAMETER
112 ERROR_DISK_FULL

Remarks

When DosSetFileSizeL is issued, the file must be open in a mode that allows write access.

The size of the open file can be truncated or extended. If the file size is being extended, the file system tries to allocate additional bytes in a contiguous (or nearly contiguous) space on the medium. The values of the new bytes are undefined.

Example Code

This example writes to a file named DOSMAN.DAT, resets the buffer, and changes the file size.

Related Functions

@@ Line 1: / Line 1: @@
-==Description==
+DosSetFileSizeL changes the size of a file.
-DosSetFileSizeL changes the size of a file.
 ==Syntax==
-<PRE>
+  DosSetFileSizeL (hFile, cbSize)
-#define INCL DOSFILEMGR
-#include  os2.h
-APIRET DosSetFileSizeL (HFILE hFile, LONGLONG cbSize)
-</PRE>
 ==Parameters==
-; hFile HFILE) input : The handle of the file whose size to be changed.
+;hFile (HFILE) input: The handle of the file whose size to be changed.
-; cbSize LONGLONG) input : The new size, in bytes, of the file.
+;cbSize ([[LONGLONG]]) input: The new size, in bytes, of the file.
 ==Return Code==
- ulrc APIRET) returns
+;ulrc (APIRET) returns:DosSetFileSizeL returns one of the following values:
+* 0 NO_ERROR
-DosSetFileSizeL returns one of the following values:
+* 5 ERROR_ACCESS_DENIED
-* 0  NO_ERROR
+* 6 ERROR_INVALID_HANDLE
-*    ERROR_ACCESS_DENIED
+*26 ERROR_NOT_DOS_DISK
-*    ERROR_INVALID_HANDLE
+*33 ERROR_LOCK_VIOLATION
-* 26 ERROR_NOT_DOS_DISK
+*87 ERROR_INVALID_PARAMETER
-* 33 ERROR_LOCK_VIOLATION
+*112 ERROR_DISK_FULL
-* 87 ERROR_INVALID_PARAMETER
-* 112 ERROR_DISK_FULL
 ==Remarks==
 When DosSetFileSizeL is issued, the file must be open in a mode that allows write access.
 The size of the open file can be truncated or extended. If the file size is being extended, the file system tries to allocate additional bytes in a contiguous (or nearly contiguous) space on the medium. The values of the new bytes are undefined.
 ==Example Code==
 This example writes to a file named DOSMAN.DAT, resets the buffer, and changes the file size.
-<PRE>
-#define INCL_DOSFILEMGR          /* File Manager values */
-#define INCL_DOSERRORS           /* DOS Error values    */
-#include  os2.h
-#include  stdio.h
-#include  string.h
-int main(VOID)
-HFILE  hfFileHandle   = 0L;     /* Handle for file being manipulated */
-ULONG  ulAction       = 0;      /* Action taken by DosOpenL */
-ULONG  ulWrote        = 0;      /* Number of bytes written by DosWrite */
-UCHAR  uchFileName 20  = "dosman.dat",     /* Name of file */
-uchFileData 4    = "DATA";            /* Data to write to file */
-APIRET rc             = NO_ERROR;            /* Return code */
-/* Open the file dosman.dat.  Use an existing file or create a new */
-/* one if it doesn't exist.                                      */
-rc = DosOpenL(uchFileName,  hfFileHandle,  ulAction, (LONGLONG)4,
-FILE_ARCHIVED | FILE_NORMAL,
-OPEN_ACTION_CREATE_IF_NEW | OPEN_ACTION_OPEN_IF_EXISTS,
-OPEN_FLAGS_NOINHERIT | OPEN_SHARE_DENYNONE  |
-OPEN_ACCESS_READWRITE, 0L);
-if (rc != NO_ERROR)
-printf("DosOpenL error  return code = %u\n", rc);
-return 1;
-rc = DosWrite (hfFileHandle, (PVOID) uchFileData,
-sizeof (uchFileData),  ulWrote);
-if (rc != NO_ERROR)
-printf("DosWrite error  return code = %u\n", rc);
-return 1;
-rc = DosResetBuffer (hfFileHandle);
-if (rc != NO_ERROR)
-printf("DosResetBuffer error  return code = %u\n", rc);
-return 1;
-  /* endif */
-rc = DosSetFileSizeL (hfFileHandle, (LONGLONG)8);    /* Change file size */
-if (rc != NO_ERROR)
-printf("DosSetFileSizeL error  return code = %u\n", rc);
-return 1;
-return NO_ERROR;
-</PRE>
 ==Related Functions==