seek

Change the access position for an open channel 

Tclsh Built-In Commands


SYNOPSIS

seek channelId offset ?origin?


DESCRIPTION

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:

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 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.

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


PORTABILITY

Windows Server 2012. Windows 8.1. Windows Server 2012 R2. Windows 10. Windows Server 2016. Windows Server 2019.


AVAILABILITY

PTC MKS Toolkit for Power Users
PTC MKS Toolkit for System Administrators
PTC MKS Toolkit for Developers
PTC MKS Toolkit for Interoperability
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition


PTC MKS Toolkit 10.3 Documentation Build 39.