ftell(3) [php man page]

FTELL(3)								 1								  FTELL(3)

ftell - Returns the current position of the file read/write pointer

SYNOPSIS

       int ftell (resource  $handle)

DESCRIPTION

	Returns the position of the file pointer referenced by $handle.

PARAMETERS

	      o $handle
		-  The	file pointer must be valid, and must point to a file successfully opened by fopen(3) or popen(3). ftell(3) gives undefined
		results for append-only streams (opened with "a" flag).

RETURN VALUES

	Returns the position of the file pointer referenced by $handle as an integer; i.e., its offset into the file stream.

	If an error occurs, returns FALSE.

       Note

	       Because PHP's integer type is signed and many platforms use 32bit integers, some filesystem functions may return unexpected results
	      for files which are larger than 2GB.

EXAMPLES

       Example #1

	      ftell(3) example

	      <?php

	      // opens a file and read some data
	      $fp = fopen("/etc/passwd", "r");
	      $data = fgets($fp, 12);

	      // where are we ?
	      echo ftell($fp); // 11

	      fclose($fp);

	      ?>

SEE ALSO

       fopen(3), popen(3), fseek(3), rewind(3).

PHP Documentation Group 														  FTELL(3)

FSEEK(3)								 1								  FSEEK(3)

fseek - Seeks on a file pointer

SYNOPSIS

       int fseek (resource  $handle, int  $offset, [int  $whence = SEEK_SET])

DESCRIPTION

	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.

	In general, it is allowed to seek past the end-of-file; if data is then written, reads in any unwritten region between the end-of-file and
       the  sought  position  will  yield bytes with value 0. However, certain streams may not support this behavior, especially when they have an
       underlying fixed size storage.

PARAMETERS

	      o $handle
		-A file system pointer resource that is typically created using fopen(3).

	      o $offset
		- The offset.  To move to a position before the end-of-file, you need to pass a negative value	in  $offset  and  set  $whence	to
		SEEK_END.

	      o $whence
		-$whence values are:

		     o SEEK_SET - Set position equal to $offset bytes.

		     o SEEK_CUR - Set position to current location plus $offset.

		     o SEEK_END - Set position to end-of-file plus $offset.

RETURN VALUES

	Upon success, returns 0; otherwise, returns -1.

EXAMPLES

       Example #1

	      fseek(3) example

	      <?php

	      $fp = fopen('somefile.txt', 'r');

	      // read some data
	      $data = fgets($fp, 4096);

	      // move back to the beginning of the file
	      // same as rewind($fp);
	      fseek($fp, 0);

	      ?>

NOTES

       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, and the result of calling fseek(3) will be undefined.

       Note

	       Not all streams support seeking. For those that do not support seeking, forward seeking from the current position  is  accomplished
	      by reading and discarding data; other forms of seeking will fail.

SEE ALSO

       ftell(3), rewind(3).

PHP Documentation Group 														  FSEEK(3)