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NAMEtell - Return current access position for an open channel SYNOPSIStell channelId DESCRIPTIONReturns an integer string giving the current access position in channelId. This value returned is a byte offset that can be passed to seek in order to set the channel to a particular position. Note that this value is in terms of bytes, not characters like read. The value returned is -1 for channels that do not support seeking. ChannelId must be an identifier for an open channel such as a Tcl standard channel (stdin, stdout, or stderr), the return value from an invocation of open or socket, or the result of a channel creation command provided by a Tcl extension. EXAMPLERead a line from a file channel only if it starts with foobar: # Save the offset in case we need to undo the read... set offset [tell $chan] if {[read $chan 6] eq "foobar"} { SEE ALSOfile(n), open(n), close(n), gets(n), seek(n), Tcl_StandardChannels(3) KEYWORDSaccess position, channel, seeking
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