pg_lo_seek

(PHP 4 >= 4.2.0, PHP 5, PHP 7)

Seeks position within a large object

bool pg_lo_seek ( resource $large_object, int $offset [, int $whence = PGSQL_SEEK_CUR ] )

pg_lo_seek() seeks a position within a large object resource.

To use the large object interface, it is necessary to enclose it within a transaction block.

Parameters:

large_object

PostgreSQL large object (LOB) resource, returned by pg_lo_open().

offset

The number of bytes to seek.

whence

One of the constants PGSQL_SEEK_SET (seek from object start), PGSQL_SEEK_CUR (seek from current position) or PGSQL_SEEK_END (seek from object end) .

Returns:

Returns TRUE on success or FALSE on failure.

Changelog:

5.6.0

Added PostgreSQL 9.3's 64bit large object support. Both client and server must support PostgreSQL 9.3 and PHP must be 64bit build to use 64bit large object.

Examples:

pg_lo_seek() example

<?php
   $doc_oid = 189762345;
   $database = pg_connect("dbname=jacarta");
   pg_query($database, "begin");
   $handle = pg_lo_open($database, $doc_oid, "r");
   // Skip first 50000 bytes
   pg_lo_seek($handle, 50000, PGSQL_SEEK_SET);
   // Read the next 10000 bytes
   $data = pg_lo_read($handle, 10000);
   pg_query($database, "commit");
   echo $data;
?>