redhat man page for read

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

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NAME
       read - Read from a channel

SYNOPSIS
       read ?-nonewline? channelId

       read channelId numChars
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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	characters |
       to  read.  Exactly that many characters will be read and returned, unless there are fewer than numChars left in the file;  in this case all |
       the remaining characters are returned.  If the channel is configured to use a multi-byte encoding, then the number of characters  read  may |
       not be the same as the number of bytes read.												   |

       If  channelId is in nonblocking mode, the command may not read as many characters as requested: once all available input has been read, the |
       command will return the data that is available rather than blocking for more input.  If the channel  is	configured  to	use  a	multi-byte |
       encoding,  then there may actually be some bytes remaining in the internal buffers that do not form a complete character.  These bytes will |
       not be returned until a complete character is available or end-of-file is reached.  The -nonewline switch is ignored if the command returns
       before reaching the end of the file.

       Read  translates  end-of-line sequences in the input into newline characters according to the -translation option for the channel.  See the
       fconfigure manual entry for a discussion on ways in which fconfigure will alter input.

SEE ALSO
       file(n), eof(n), fblocked(n), fconfigure(n)

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

Tcl									8.1								   read(n)