(PHP 4, PHP 5)
fseek — Seeks on a file pointer
Sets the file position indicator for the file referenced by handle . The new position, measured in bytes from the beginning of the file, is obtained by adding offset to the position specified by whence .
To move to a position before the end-of-file, you need to pass a negative value in offset .
whence values are:
- SEEK_SET - Set position equal to offset bytes.
- SEEK_CUR - Set position to current location plus offset .
- SEEK_END - Set position to end-of-file plus offset .
If whence is not specified, it is assumed to be SEEK_SET.
Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error.
Example#1 fseek() example
$fp = fopen('somefile.txt', 'r');
// read some data
$data = fgets($fp, 4096);
// move back to the beginning of the file
// same as rewind($fp);
Note: If you have opened the file in append ("a" or "a+") mode, any data you write to the file will always be appended, regardless of the file position.
Note: May not be used on file pointers returned by fopen() if they use the "https://" or "ftp://" formats. fseek() gives also undefined results for append-only streams (opened with "a" flag).