NAME
       seek - Change the access position for an open channel

SYNOPSIS
       seek channelId offset ?origin?


DESCRIPTION
       Changes  the current access position for channelId.  Chan-
       nelId must be a channel identifier such as returned from a
       previous  invocation  of  open  or socket.  The offset and
       origin arguments specify the position at  which  the  next
       read  or write will occur for channelId. Offset must be an
       integer (which may be negative) and origin must be one  of
       the following:

       start     The  new  access  position  will be offset bytes
                 from the start of the underlying file or device.

       current   The  new  access  position  will be offset bytes
                 from the current  access  position;  a  negative
                 offset  moves  the  access position backwards in
                 the underlying file or device.

       end       The new access position  will  be  offset  bytes
                 from  the end of the file or device.  A negative
                 offset places the access position before the end
                 of file, and a positive offset places the access
                 position after the end of file.

       The origin argument defaults to start.

       The command flushes all buffered output  for  the  channel
       before the command returns, even if the channel is in non-
       blocking mode.  It also discards any buffered  and  unread
       input.   This  command  returns an empty string.  An error
       occurs if this command is applied to channels whose under-
       lying file or device does not support seeking.

       Note  that  offset  values are byte offsets, not character
       offsets.  Both seek and tell operate in  terms  of  bytes,
       not characters, unlike read.


KEYWORDS
       access position, file, seek
