fseek(3f) [bsd man page]

FSEEK(3F)																 FSEEK(3F)

NAME

       fseek, ftell - reposition a file on a logical unit

SYNOPSIS

       integer function fseek (lunit, offset, from)
       integer offset, from

       integer function ftell (lunit)

DESCRIPTION

       lunit  must refer to an open logical unit.  offset is an offset in bytes relative to the position specified by from.  Valid values for from
       are:

	    0 meaning `beginning of the file'
	    1 meaning `the current position'
	    2 meaning `the end of the file'

       The value returned by fseek will be 0 if successful, a system error code otherwise.  (See perror(3F))

       Ftell returns the current position of the file associated with the specified logical unit. The value is	an  offset,  in  bytes,  from  the
       beginning  of  the  file.  If the value returned is negative, it indicates an error and will be the negation of the system error code. (See
       perror(3F))

FILES

       /usr/lib/libU77.a

SEE ALSO

       fseek(3S), perror(3F)

4.2 Berkeley Distribution					   May 27, 1986 							 FSEEK(3F)

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)