PHP fseek()Functions

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Definition and Usage

The fseek() function seeks in an open file.

This function moves the file pointer forward or backward from its current position to a new position. The new position is measured in bytes from the beginning of the file.

Returns 0 on success, or -1 on failure. Note that moving to a position beyond the end of file (EOF) is not an error.

Syntax

fseek(file,offset,whence)

Parameter Description
file Required. Specifies the file to seek in.
offset Required. Specifies the new position (measured in bytes from the beginning of the file).
whence Optional. (Added in PHP 4). Possible values:
  • SEEK_SET - Set position equal to offset. Default.
  • SEEK_CUR - Set position to current position plus offset.
  • SEEK_END - Set position to end of file (EOF) plus offset (to move to a position before EOF, offset must be a negative value).

Tips and Notes

Tip:Use ftell() to find the current position!

Example

<?php
$file = fopen("test.txt","r");
// read first line
fgets($file);
// move back to beginning of file
fseek($file,0);
?>

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