NAME
       puts - Write to a channel

SYNOPSIS
       puts ?-nonewline? ?channelId? string


DESCRIPTION
       Writes  the  characters  given  by string to the channel given by chan-
       nelId.  ChannelId must be a channel identifier such as returned from  a
       previous  invocation  of  open  or socket. It 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 operat-
       ing  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 back-
       ground 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)


KEYWORDS
