Tcl Built-In Commands - read manual page

### 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 -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 manual entry for fconfigure for details on the -translation option.

### SEE ALSO

eof, fblocked, fconfigure

### KEYWORDS

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

    Copyright © 1993 The Regents of the University of California.
    Copyright © 1994-1996 Sun Microsystems, Inc.
    Copyright © 1995-1997 Roger E. Critchlow Jr.