close channelId
If the channel is blocking, the command does not return until all output is flushed. If the channel is nonblocking and there is unflushed output, the channel remains open and the command returns immediately; output will be flushed in the background and the channel will be closed when all the flushing is complete.
If channelId is a blocking channel for a command pipeline then
close waits for the child processes to complete.
If the channel is shared between interpreters, then close
makes channelId unavailable in the invoking interpreter but has no
other effect until all of the sharing interpreters have closed the
channel.
When the last interpreter in which the channel is registered invokes
close, the cleanup actions described above occur. See the
interp command for a description of channel sharing.
Channels are automatically closed when an interpreter is destroyed and
when the process exits. Channels are switched to blocking mode, to ensure
that all output is correctly flushed before the process exits.
The command returns an empty string, and may generate an error if an error occurs while flushing output.
Copyright © 1989-1994 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.