Tcl Built-In Commands
seek - Change the access position for an open channel
seek channelId offset ?origin?
Changes the current access position for channelId.
ChannelId 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:
The new access position will be offset bytes from the start
of the underlying file or device.
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.
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 nonblocking 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 underlying
file or device does not support seeking.
access position, file, seek
Last change: 7.5
[ tcl8.0a1 | tk8.0a1 | X-ref ]
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