read(n) Tcl Built-In Commands read(n)______________________________________________________________________________NAMEread - Read from a channel
SYNOPSISread ?-nonewline? channelId
read channelId numBytes
_________________________________________________________________DESCRIPTION
In the first form, the read command reads all of the data from chan‐
nelId 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 remain‐
ing 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 com‐
mand 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 charac‐
ters according to the -translation option for the channel. See the
manual entry for fconfigure for details on the -translation option.
SEE ALSOeof(n), fblocked(n), fconfigure(n)KEYWORDS
blocking, channel, end of line, end of file, nonblocking, read, trans‐
lation
Tcl 7.5 read(n)