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SunOS man pages : read (1)

Tcl Built-In Commands                                     read(n)



read - Read from a channel


read ?-nonewline? channelId read channelId numChars _________________________________________________________________


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 new- line 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.


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


blocking, channel, end of line, end of file, nonblocking, read, translation, encoding Tcl Last change: 8.1 1