fseek ()

The fseek() function searches pointer in an open file and used to move from its current position to a new position, forward, backward as per specified by number of bytes. It returns 0 if succeed or -1 in the case of failure. 

If any file has been opened in the append mode, the data written on the file will also be appended. 

Syntax

fseek(file,offset,whence) 

Parameter

File - File is essential as it is the source. 

Offset - Offset is also essential that specifies the new position of the pointer

Whence - Whence is optional. It has three possible value.  

Possible values:

SEEK_SET - Set position equal to offset. It is a default value and when whence is not specified, it automatically as SEEK_SET
SEEK_CUR - Set position to current location plus offset
SEEK_END - Set position to EOF plus offset (to move to a position before EOF, the offset must be a negative value)

Example:

<?php
$filename = "New Text Document .txt";
$fp = fopen( $filename, "r" ) or die("Couldn't open $filename");

$fsize = filesize($filename);
$midfway = (int)( $fsize / 2 );

print "Middle point: $midfway <BR>\n";
fseek( $fp, $midfway );

$chunk = fread( $fp, ($fsize - $midfway) );
print $chunk;
?>

Related Tags for fseek() example: