isc_portable_integer()
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Reverses the byte order of an integer. This supports INT64 (8 byte integer) values and is a superset of isc_vax_integer(), which supports only up to LONG (4 bytes) values.
Syntax
ISC_INT64 isc_portable_integer(
char *buffer,
short length);
| Parameter | Type | Description |
|---|---|---|
|
|
|
Pointer to the integer to convert |
|
|
|
Length, in bytes, of the integer to convert Valid lengths are 1, 2, 4, and 8 bytes. |
Description
isc_portable_integer() reverses the byte order of an integer, specified in buffer, and returns the newly ordered value.
A typical use for this function is to convert integer values passed into a database parameter buffer to a format where the least significant byte must be first and the most significant byte last. In InterBase, integer values must be represented in input parameter buffers (for example, the DPB) and are returned in result buffers in a generic format where the least significant byte is first, and the most significant byte last. isc_portable_integer() is used to convert integers to and from this format.
Example
The following code fragment converts a 2-byte value, stored in a character buffer that is the result buffer returned by a function such as isc_database_info():
#include <ibase.h>
char *p;
. . .
for(p = res_buffer; *p != isc_info_end;) {
/* Read item type of next cluster in the result buffer. */
item = *p++;
/* Read length of next value in result buffer, and convert. */
len = isc_portable_integer(p, 2);
p += len;
/* Now process the actual value, len bytes in size. */
}
Return value
isc_portable_integer() always returns a byte-reversed INT64 (8 byte) value.