tcl7.6 User Commands - read






NAME

     read - Read from a channel


SYNOPSIS

     read ?-nonewline? channelId

     read channelId numBytes





DESCRIPTION

     In the first form, the read command reads all  of  the  data
     from channelId up to the end of the file.  If the -nonewline
     switch is specified then the last character of the  file  is
     discarded if it is a newline.  In the second form, the extra
     argument specifies how many bytes  to  read.   Exactly  that
     many bytes will be read and returned, unless there are fewer
     than numBytes left in  the  file;   in  this  case  all  the
     remaining bytes are returned.

     If channelId is in nonblocking mode,  the  command  may  not
     read  as  many bytes as requested:  once all available input
     has been read, the command will  return  the  data  that  is
     available  rather than blocking for more input.  The -nonew-
     line switch is ignored if the command returns before  reach-
     ing the end of the file.

     Read translates end-of-line sequences in the input into new-
     line characters according to the -translation option for the
     channel.  See the manual entry for fconfigure for details on
     the -translation option.



SEE ALSO

     eof(n), fblocked(n), fconfigure(n)



KEYWORDS

     blocking, channel, end of line, end  of  file,  nonblocking,
     read, translation