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flush(n) [osx man page]

flush(n)						       Tcl Built-In Commands							  flush(n)

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NAME
flush - Flush buffered output for a channel SYNOPSIS
flush channelId _________________________________________________________________ DESCRIPTION
Flushes any output that has been buffered for channelId. ChannelId must be an identifier for an open channel such as a Tcl standard channel (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. The channel must have been opened for writing. If the channel is in blocking mode the command does not return until all the buffered output has been flushed to the channel. If the chan- nel is in nonblocking mode, the command may return before all buffered output has been flushed; the remainder will be flushed in the back- ground as fast as the underlying file or device is able to absorb it. EXAMPLE
Prompt for the user to type some information in on the console: puts -nonewline "Please type your name: " flush stdout gets stdin name puts "Hello there, $name!" SEE ALSO
file(n), open(n), socket(n), Tcl_StandardChannels(3) KEYWORDS
blocking, buffer, channel, flush, nonblocking, output Tcl 7.5 flush(n)

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puts(n) 						       Tcl Built-In Commands							   puts(n)

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NAME
puts - Write to a channel SYNOPSIS
puts ?-nonewline? ?channelId? string _________________________________________________________________ DESCRIPTION
Writes the characters given by string to the channel given by channelId. ChannelId must be an identifier for an open channel such as a Tcl standard channel (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. The channel must have been opened for output. If no channelId is specified then it defaults to stdout. Puts normally outputs a newline character after string, but this feature may be suppressed by specifying the -nonewline switch. Newline characters in the output are translated by puts to platform-specific end-of-line sequences according to the current value of the -translation option for the channel (for example, on PCs newlines are normally replaced with carriage-return-linefeed sequences; on Macin- toshes newlines are normally replaced with carriage-returns). See the fconfigure manual entry for a discussion on ways in which fconfigure will alter output. Tcl buffers output internally, so characters written with puts may not appear immediately on the output file or device; Tcl will normally delay output until the buffer is full or the channel is closed. You can force output to appear immediately with the flush command. When the output buffer fills up, the puts command will normally block until all the buffered data has been accepted for output by the oper- ating system. If channelId is in nonblocking mode then the puts command will not block even if the operating system cannot accept the data. Instead, Tcl continues to buffer the data and writes it in the background as fast as the underlying file or device can accept it. The application must use the Tcl event loop for nonblocking output to work; otherwise Tcl never finds out that the file or device is ready for more output data. It is possible for an arbitrarily large amount of data to be buffered for a channel in nonblocking mode, which could consume a large amount of memory. To avoid wasting memory, nonblocking I/O should normally be used in an event-driven fashion with the fileevent command (don't invoke puts unless you have recently been notified via a file event that the channel is ready for more output data). SEE ALSO
file(n), fileevent(n), Tcl_StandardChannels(3) KEYWORDS
channel, newline, output, write Tcl 7.5 puts(n)
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