4D v13.4

LONGINT TO BLOB

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4D v13.4
LONGINT TO BLOB

LONGINT TO BLOB 


 

LONGINT TO BLOB ( longInt ; blob ; byteOrder {; offset | *} )  
Parameter Type   Description
longInt  Longint in Long Integer value to write into the BLOB
blob  BLOB in BLOB to receive the Long Integer value
byteOrder  Longint in 0 Native byte ordering 1 Macintosh byte ordering 2 PC byte ordering
offset | *  Variable, Operator in Offset within the BLOB (expressed in bytes) or * to append the value
in New offset after writing if not *

The LONGINT TO BLOB command writes the 4-byte Long Integer value integer into the BLOB blob.

The byteOrder parameter fixes the byte ordering of the 4-byte Long Integer value to be written. You pass one of the following predefined constants provided by 4D:

Constant Type Value
Macintosh byte ordering Longint 1
Native byte ordering Longint 0
PC byte ordering Longint 2

Note regarding Platform Independence: If you exchange BLOBs between Macintosh and PC platforms, it is up to you to manage byte swapping issues while using this command.

If you specify the * optional parameter, the 4-byte Long Integer value is appended to the BLOB and the size of the BLOB is extended accordingly. Using the * optional parameter, you can sequentially store any number of Integer, Long Integer, Real or Text values (see other BLOB commands) in a BLOB, as long as the BLOB fits into memory.

If you do not specify the * optional parameter nor the offset variable parameter, the 4-byte Long Integer value is stored at the beginning of the BLOB, overriding its previous contents; the size of the BLOB is adjusted accordingly.

If you pass the offset variable parameter, the 4-byte Long Integer value is written at the offset (starting from zero) within the BLOB. No matter where you write the 4-byte Long Integer value, the size of the BLOB is increased according to the location you passed (plus up to 4 bytes, if necessary). New allocated bytes, other than the ones you are writing, are initialized to zero.

After the call, the offset variable parameter is returned, incremented by the number of bytes that have been written. Therefore, you can reuse that same variable with another BLOB writing command to write another value.

After executing this code:

 LONGINT TO BLOB(0x01020304;vxBlob;Native byte ordering)
  • The size of vxBlob is 4 bytes
  • On PowerPC platform: vxBLOB{0}=$01, vxBLOB{1}=$02, vxBLOB{2}=$03, vxBLOB{3}=$04
  • On Intel platform: vxBLOB{0}=$04, vxBLOB{1}=$03, vxBLOB{2}=$02, vxBLOB{3}=$01

After executing this code:

 LONGINT TO BLOB(0x01020304;vxBlob;Macintosh byte ordering)
  • The size of vxBlob is 4 bytes
  • On all platforms vxBLOB{0}=$01, vxBLOB{1}=$02, vxBLOB{2}=$03, vxBLOB{3}=$04

After executing this code:

 LONGINT TO BLOB(0x01020304;vxBlob;PC byte ordering)
  • The size of vxBlob is 4 bytes
  • On all platforms vxBLOB{0}=$04, vxBLOB{1}=$03, vxBLOB{2}=$02, vxBLOB{3}=$01

After executing this code:

 SET BLOB SIZE(vxBlob;100)
 LONGINT TO BLOB(0x01020304;vxBlob;PC byte ordering;*)
  • The size of vxBlob is 104 bytes
  • On all platforms vxBLOB{100}=$04, vxBLOB{101}=$03, vxBLOB{102}=$02, vxBLOB{103}=$01
  • The other bytes of the BLOB are left unchanged

After executing this code:

 SET BLOB SIZE(vxBlob;100)
 vlOffset:=50
 LONGINT TO BLOB(0x01020304;vxBlob;Macintosh byte ordering;vlOffset)
  • The size of vxBlob is 100 bytes
  • On all platforms vxBLOB{50}=$01, vxBLOB{51}=$02, vxBLOB{52}=$03, vxBLOB{53}=$04
  • The other bytes of the BLOB are left unchanged
  • The variable vlOffset has been incremented by 4 (and is now equal to 54)

 
PROPERTIES 

Product: 4D
Theme: BLOB
Number: 550

 
INDEX

Alphabetical list of commands

 
HISTORY 

Created: 4D v6

 
SEE ALSO 

BLOB to integer
BLOB to longint
BLOB to real
BLOB to text
INTEGER TO BLOB
REAL TO BLOB
TEXT TO BLOB

 
TAGS 

Longint***