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



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NAME
     read - Read from a channel

SYNOPSIS
     read ?-nonewline? _c_h_a_n_n_e_l_I_d

     read _c_h_a_n_n_e_l_I_d _n_u_m_B_y_t_e_s
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DESCRIPTION
     In the first form, the read command reads all  of  the  data
     from _c_h_a_n_n_e_l_I_d 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 _n_u_m_B_y_t_e_s left in  the  file;   in  this  case  all  the
     remaining bytes are returned.

     If _c_h_a_n_n_e_l_I_d 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













Tcl                     Last change: 7.5                        1