Merge trunk

1 files changed, 507 insertions, 355 deletions

diff --git a/doc/chan.n b/doc/chan.n
index 2f8b0a4..8bb564b 100644
--- a/doc/chan.n
+++ b/doc/chan.n
@@ -1,6 +1,5 @@
 '\"
 '\" Copyright (c) 2005-2006 Donal K. Fellows
-'\" Copyright (c) 2021 Nathan Coulter
 '\"
 '\" See the file "license.terms" for information on usage and redistribution
 '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
@@ -9,68 +8,85 @@
 .BS
 '\" Note:  do not modify the .SH NAME line immediately below!
 .SH NAME
-chan \- Reads, writes and manipulates channels.
+chan \- Read, write and manipulate channels
 .SH SYNOPSIS
-\fBchan \fIoperation\fR ?\fIarg arg ...\fR?
+\fBchan \fIoption\fR ?\fIarg arg ...\fR?
 .BE
 .SH DESCRIPTION
 .PP
-\fBchan\fR provides several operations for reading from, writing to, and
-otherwise manipulating channels, e.g. those created by \fBopen\fR and
-\fBsocket\fR, or the default channels \fBstdin\fR, \fBstdout\fR or \fBstderr\fR
-which correspond respectively to the standard input, output, and error streams
-of the process.  Any unique abbreviation for \fIoperation\fR is acceptable.
-Available operations are:
+This command provides several operations for reading from, writing to
+and otherwise manipulating open channels (such as have been created
+with the \fBopen\fR and \fBsocket\fR commands, or the default named
+channels \fBstdin\fR, \fBstdout\fR or \fBstderr\fR which correspond to
+the process's standard input, output and error streams respectively).
+\fIOption\fR indicates what to do with the channel; any unique
+abbreviation for \fIoption\fR is acceptable. Valid options are:
 .\" METHOD: blocked
 .TP
-\fBchan blocked \fIchannelName\fR
+\fBchan blocked \fIchannelId\fR
 .
-Returns 1 when the channel is in non-blocking mode and the last input operation
-on the channel failed because it would have otherwise caused the process to
-block, and 0 otherwise.  Each Tcl channel is in blocking mode unless configured
-otherwise.
+This tests whether the last input operation on the channel called
+\fIchannelId\fR failed because it would have otherwise caused the
+process to block, and returns 1 if that was the case. It returns 0
+otherwise. Note that this only ever returns 1 when the channel has
+been configured to be non-blocking; all Tcl channels have blocking
+turned on by default.
 .\" METHOD: close
 .TP
-\fBchan close \fIchannelName\fR ?\fIdirection\fR?
+\fBchan close \fIchannelId\fR ?\fIdirection\fR?
 .
-Closes and destroys the named channel deleting any existing event handlers
-established for the channel. The command returns the empty string. If
-\fIdirection\fR is given, it is \fBread\fR, or \fBwrite\fR, or any unique
-abbreviation of those words, and only that side of the channel is closed. I.e. a
-read-write channel may become read-only or write-only. Closing a read-only
-channel for reading, or closing a write-only channel for writing is the same as
-simply closing the channel. It is an error to close a read-only channel for
-writing or to close a write-only channel for reading.
+Close and destroy the channel called \fIchannelId\fR. Note that this
+deletes all existing file-events registered on the channel.
+If the \fIdirection\fR argument (which must be \fBread\fR or \fBwrite\fR or
+any unique abbreviation of them) is present, the channel will only be
+half-closed, so that it can go from being read-write to write-only or
+read-only respectively. If a read-only channel is closed for reading, it is
+the same as if the channel is fully closed, and respectively similar for
+write-only channels. Without the \fIdirection\fR argument, the channel is
+closed for both reading and writing (but only if those directions are
+currently open). It is an error to close a read-only channel for writing, or a
+write-only channel for reading.
 .RS
 .PP
-When a channel is closed for writing, any buffered output on the channel is
-flushed. When a channel is closed for reading, any buffered input is discarded.
-When a channel is destroyed the underlying resource is closed and the channel
-is thereafter unavailable.
-.PP
-\fBchan close\fR fully flushes any output before closing the write side of a
-channel unless it is non-blocking mode, where it returns immediately and the
-channel is flushed in the background before finally being closed.
-.PP
-\fBchan close\fR may return an error if an error occurs while flushing
-output.  If a process in a command pipeline created by \fBopen\fR returns an
-error (either by returning a non-zero exit code or writing to its standard
-error file descriptor), \fBchan close\fR generates an error in the same
-manner as \fBexec\fR.
-.PP
-Closing one side of a socket or command pipeline may lead to the shutdown() or
-close() of the underlying system resource, leading to a reaction from whatever
-is on the other side of the pipeline or socket.
-.PP
-If the channel for a command pipeline is in blocking mode, \fBchan close\fR
-waits for the connected processes to complete.
-.PP
-\fBchan close\fR only affects the current interpreter.  If the channel is open
-in any other interpreter, its state is unchanged there.  See \fBinterp\fR for a
-description of channel sharing.
-.PP
-When the last interpreter sharing a channel is destroyed, the channel is
-switched to blocking mode and fully flushed and then closed.
+As part of closing the channel, all buffered output is flushed to the
+channel's output device (only if the channel is ceasing to be writable), any
+buffered input is discarded (only if the channel is ceasing to be readable),
+the underlying operating system resource is closed and \fIchannelId\fR becomes
+unavailable for future use (both only if the channel is being completely
+closed).
+.PP
+If the channel is blocking and the channel is ceasing to be writable, the
+command does not return until all output is flushed.  If the channel is
+non-blocking and there is unflushed output, the channel remains open and the
+command returns immediately; output will be flushed in the background and the
+channel will be closed when all the flushing is complete.
+.PP
+If \fIchannelId\fR is a blocking channel for a command pipeline then
+\fBchan close\fR waits for the child processes to complete.
+.PP
+If the channel is shared between interpreters, then \fBchan close\fR
+makes \fIchannelId\fR unavailable in the invoking interpreter but has
+no other effect until all of the sharing interpreters have closed the
+channel. When the last interpreter in which the channel is registered
+invokes \fBchan close\fR (or \fBclose\fR), the cleanup actions
+described above occur. With half-closing, the half-close of the channel only
+applies to the current interpreter's view of the channel until all channels
+have closed it in that direction (or completely).
+See the \fBinterp\fR command for a description of channel sharing.
+.PP
+Channels are automatically fully closed when an interpreter is destroyed and
+when the process exits.  Channels are switched to blocking mode, to
+ensure that all output is correctly flushed before the process exits.
+.PP
+The command returns an empty string, and may generate an error if
+an error occurs while flushing output.  If a command in a command
+pipeline created with \fBopen\fR returns an error, \fBchan close\fR
+generates an error (similar to the \fBexec\fR command.)
+.PP
+Note that half-closes of sockets and command pipelines can have important side
+effects because they result in a shutdown() or close() of the underlying
+system resource, which can change how other processes or systems respond to
+the Tcl program.
 .PP
 Channels are automatically closed when an interpreter is destroyed and
 when the process exits.
@@ -85,81 +101,105 @@ restores the previous behavior.
 .RE
 .\" METHOD: configure
 .TP
-\fBchan configure \fIchannelName\fR ?\fIoptionName\fR? ?\fIvalue\fR? ?\fIoptionName value\fR?...
+\fBchan configure \fIchannelId\fR ?\fIoptionName\fR? ?\fIvalue\fR? ?\fIoptionName value\fR?...
 .
-Configures or retrieves the configuration of the channel \fIchannelName\fR.
+Query or set the configuration options of the channel named
+\fIchannelId\fR.
 .RS
 .PP
-If no \fIoptionName\fR or \fIvalue\fR arguments are given,
-\fBchan configure\fR returns a dictionary of option names and
-values for the channel.  If \fIoptionName\fR is supplied without a \fIvalue\fR,
-\fBchan configure\fR returns the current value of the named option.  If one or
-more pairs of \fIoptionName\fR and \fIvalue\fR are supplied,
-\fBchan configure\fR sets each of the named options to the corresponding
-\fIvalue\fR and returns the empty string.
-.PP
-The options described below are supported for all channels. Each type of
-channel may provide additional options. Those options are described in the
-relevant documentation. For example, additional options are documented for
-\fBsocket\fR, and also for serial devices at \fBopen\fR.
+If no \fIoptionName\fR or \fIvalue\fR arguments are supplied, the
+command returns a list containing alternating option names and values
+for the channel.  If \fIoptionName\fR is supplied but no \fIvalue\fR
+then the command returns the current value of the given option.  If
+one or more pairs of \fIoptionName\fR and \fIvalue\fR are supplied,
+the command sets each of the named options to the corresponding
+\fIvalue\fR; in this case the return value is an empty string.
+.PP
+The options described below are supported for all channels. In
+addition, each channel type may add options that only it supports. See
+the manual entry for the command that creates each type of channel
+for the options supported by that specific type of channel. For
+example, see the manual entry for the \fBsocket\fR command for additional
+options for sockets, and the \fBopen\fR command for additional options for
+serial devices.
+.RE
 .\" OPTION: -blocking
 .TP
 \fB\-blocking\fI boolean\fR
 .
-If \fB\-blocking\fR is set to \fBtrue\fR (default), reading the channel
-or writing to it may cause the process to block indefinitely.  Otherwise,
-operations such as \fBchan gets\fR, \fBchan read\fR, \fBchan puts\fR, \fBchan
-flush\fR, and \fBchan close\fR take care not to block.  Non-blocking mode in
-general requires that the event loop is entered, e.g. by calling
-\fBTcl_DoOneEvent\fR or \fBvwait\fR or by using Tk, to give Tcl a chance to
-process events on the channel.
+The \fB\-blocking\fR option determines whether I/O operations on the
+channel can cause the process to block indefinitely.  The value of the
+option must be a proper boolean value.  Channels are normally in
+blocking mode; if a channel is placed into non-blocking mode it will
+affect the operation of the \fBchan gets\fR, \fBchan read\fR, \fBchan
+puts\fR, \fBchan flush\fR, and \fBchan close\fR commands; see the
+documentation for those commands for details.  For non-blocking mode to
+work correctly, the application must be using the Tcl event loop
+(e.g. by calling \fBTcl_DoOneEvent\fR or invoking the \fBvwait\fR
+command).
 .\" OPTION: -buffering
 .TP
 \fB\-buffering\fI newValue\fR
 .
-If \fInewValue\fR is \fBfull\fR, which is the default, output is buffered
-until the internal buffer is full or until \fBchan flush\fR is called. If
-\fInewValue\fR is \fBline\fR, output is flushed each time a end-of-line
-character is written. If \fInewValue\fR is \fBnone\fR, output is flushed after
-every output operation.  For \fBstdin\fR, \fBstdout\fR, and channels that
-connect to terminal-like devices, the default value is \fBline\fR.  For
-\fBstderr\fR the default value is \fBnone\fR.
+If \fInewValue\fR is \fBfull\fR then the I/O system will buffer output
+until its internal buffer is full or until the \fBchan flush\fR
+command is invoked. If \fInewValue\fR is \fBline\fR, then the I/O
+system will automatically flush output for the channel whenever a
+newline character is output. If \fInewValue\fR is \fBnone\fR, the I/O
+system will flush automatically after every output operation.  The
+default is for \fB\-buffering\fR to be set to \fBfull\fR except for
+channels that connect to terminal-like devices; for these channels the
+initial setting is \fBline\fR.  Additionally, \fBstdin\fR and
+\fBstdout\fR are initially set to \fBline\fR, and \fBstderr\fR is set
+to \fBnone\fR.
 .\" OPTION: -buffersize
 .TP
 \fB\-buffersize\fI newSize\fR
 .
-\fInewSize\fR, an integer no greater than one million, is the size in bytes of
-any input or output buffers subsequently allocated for this channel.
+\fInewSize\fR must be an integer; its value is used to set the size
+of buffers, in bytes, subsequently allocated for this channel to store
+input or output. \fInewSize\fR must be a number of no more than one
+million, allowing buffers of up to one million bytes in size.
 .\" OPTION: -encoding
 .TP
 \fB\-encoding\fR \fIname\fR
 .
-Sets the encoding of the channel to \fIname\fR which should be one of the names
-returned by \fBencoding names\fR, or
-.QW \fBbinary\fR
-\&. Input is converted from the encoding into Unicode, and output is converted
-from Unicode to the encoding.
+This option is used to specify the encoding of the channel as one of
+the named encodings returned by \fBencoding names\fR or the special
+value \fBbinary\fR, so that the data can be converted to and from
+Unicode for use in Tcl.  For instance, in order for Tcl to read
+characters from a Japanese file in \fBshiftjis\fR and properly process
+and display the contents, the encoding would be set to \fBshiftjis\fR.
+Thereafter, when reading from the channel, the bytes in the Japanese
+file would be converted to Unicode as they are read.  Writing is also
+supported \- as Tcl strings are written to the channel they will
+automatically be converted to the specified encoding on output.
 .RS
 .PP
-\fBbinary\fR is an alias for \fBiso8859-1\fR.  This alone is not sufficient for
-working with binary data.  Use \fB\-translation binary\fR instead.
-.PP
-The encoding of a new channel is the value of \fBencoding system\fR,
-which returns the platform- and locale-dependent system encoding used to
-interface with the operating system,
+If a file contains pure binary data (for instance, a JPEG image), the
+encoding for the channel should be configured to be \fBbinary\fR.  Tcl
+will then assign no interpretation to the data in the file and simply
+read or write raw bytes.  The Tcl \fBbinary\fR command can be used to
+manipulate this byte-oriented data.  It is usually better to set the
+\fB\-translation\fR option to \fBbinary\fR when you want to transfer
+binary data, as this turns off the other automatic interpretations of
+the bytes in the stream as well.
+.PP
+The default encoding for newly opened channels is the same platform-
+and locale-dependent system encoding used for interfacing with the
+operating system, as returned by \fBencoding system\fR.
 .RE
 .\" OPTION: -eofchar
 .TP
 \fB\-eofchar\fI char\fR
 .
-\fIchar\fR signals the end of the data when it is encountered in the input.
-If \fIchar\fR is the empty string, there is no special character that marks
-the end of the data.
-.RS
-.PP
-The default value is the empty string.  The acceptable range is \ex01 -
-\ex7F.  A value outside this range results in an error.
-.RE
+This option supports DOS file systems that use Control-z (\ex1A) as an
+end of file marker.  If \fIchar\fR is not an empty string, then this
+character signals end-of-file when it is encountered during input.
+Otherwise (the default) there is no special end of file character marker.
+The acceptable range for \fB\-eofchar\fR values is \ex01 - \ex7f;
+attempting to set \fB\-eofchar\fR to a value outside of this range will
+generate an error.
 .VS "TCL8.7 TIP656"
 .\" OPTION: -profile
 .TP
@@ -177,32 +217,41 @@ profiles.
 .TP
 \fB\-translation\fR \fB{\fIinTranslation outTranslation\fB}\fR
 .
-In Tcl a single line feed (\en) represents the end of a line.  However,
-at the destination the end of a line may be represented differently on
-different platforms, or even for different devices on the same platform.  For
-example, under UNIX line feed is used in files and a
-carriage-return-linefeed sequence is normally used in network connections.
-Therefore, on input, e.g. with \fBchan gets\fR and \fBchan read\fR, each
-external end-of-line character is translated into a line feed.  On
-output, e.g. with \fBchan puts\fR, each line feed is translated to the external
-end-of-line character.  The default translation, \fBauto\fR, handles all the
-common cases, and \fB\-translation\fR provides explicit control over the
-end-of-line character.
+In Tcl scripts the end of a line is always represented using a single
+newline character (\en).  However, in actual files and devices the end
+of a line may be represented differently on different platforms, or
+even for different devices on the same platform.  For example, under
+UNIX newlines are used in files, whereas carriage-return-linefeed
+sequences are normally used in network connections.  On input (i.e.,
+with \fBchan gets\fR and \fBchan read\fR) the Tcl I/O system
+automatically translates the external end-of-line representation into
+newline characters.  Upon output (i.e., with \fBchan puts\fR), the I/O
+system translates newlines to the external end-of-line representation.
+The default translation mode, \fBauto\fR, handles all the common cases
+automatically, but the \fB\-translation\fR option provides explicit
+control over the end of line translations.
 .RS
 .PP
-Returns the input translation for a read-only channel, the output translation
-for a write-only channel, and both the input translation and the output
-translation for a  read-write channel.  When two translations are given, they
-are the input and output translation, respectively.  When only one translation
-is given for a read-write channel, it is the translation for both input and
-output.  The following values are currently supported:
+The value associated with \fB\-translation\fR is a single item for
+read-only and write-only channels.  The value is a two-element list for
+read-write channels; the read translation mode is the first element of
+the list, and the write translation mode is the second element.  As a
+convenience, when setting the translation mode for a read-write channel
+you can specify a single value that will apply to both reading and
+writing.  When querying the translation mode of a read-write channel, a
+two-element list will always be returned.  The following values are
+currently supported:
 .IP \fBauto\fR
-The default.  For input each occurrence of a line feed (\fBlf\fR), carriage
-return (\fBcr\fR), or carriage return followed by a line feed (\fBcrlf\fR) is
-translated into a line feed.  For output, each line feed is translated into a
-platform-specific representation:  For all Unix variants it is \fBlf\fR, and
-for all Windows variants it is \fBcrlf\fR, except that for sockets on all
-platforms it is \fBcrlf\fR for both input and output.
+As the input translation mode, \fBauto\fR treats any of newline
+(\fBlf\fR), carriage return (\fBcr\fR), or carriage return followed by
+a newline (\fBcrlf\fR) as the end of line representation.  The end of
+line representation can even change from line-to-line, and all cases
+are translated to a newline.  As the output translation mode,
+\fBauto\fR chooses a platform specific representation; for sockets on
+all platforms Tcl chooses \fBcrlf\fR, for all Unix flavors, it chooses
+\fBlf\fR, and for the various flavors of Windows it chooses
+\fBcrlf\fR.  The default setting for \fB\-translation\fR is \fBauto\fR
+for both input and output.
 .IP \fBbinary\fR
 Like \fBlf\fR, no end-of-line translation is performed, but in addition, sets
 \fB\-eofchar\fR to the empty string to disable it, and sets \fB\-encoding\fR
@@ -215,21 +264,24 @@ in the data remains in the range of 0 to 255 so that there is no distinction
 between binary data and text.  For example, A JPEG image can be read from a
 such a channel, manipulated, and then written back to such a channel.
 .IP \fBcr\fR
-The end of a line is represented in the external data by a single carriage
-return character.  For input, each carriage return is translated to a line
-feed, and for output each line feed character is translated to a carriage
-return.
+The end of a line in the underlying file or device is represented by a
+single carriage return character.  As the input translation mode,
+\fBcr\fR mode converts carriage returns to newline characters.  As the
+output translation mode, \fBcr\fR mode translates newline characters
+to carriage returns.
 .IP \fBcrlf\fR
-The end of a line is represented in the external data by a carriage return
-character followed by a line feed.  For input, each carriage-return-linefeed
-sequence is translated to a line feed.  For output, each line feed is
-translated to a carriage-return-linefeed sequence.  This translation is
-typically used for network connections, and also on Windows systems.
+The end of a line in the underlying file or device is represented by a
+carriage return character followed by a linefeed character.  As the
+input translation mode, \fBcrlf\fR mode converts
+carriage-return-linefeed sequences to newline characters.  As the
+output translation mode, \fBcrlf\fR mode translates newline characters
+to carriage-return-linefeed sequences.  This mode is typically used on
+Windows platforms and for network connections.
 .IP \fBlf\fR
-The end of a line in the external data is represented by a line feed so no
-translations occur during either input or output.  This translation is
-typically used on UNIX platforms,
-.RE
+The end of a line in the underlying file or device is represented by a
+single newline (linefeed) character.  In this mode no translations
+occur during either input or output.  This mode is typically used on
+UNIX platforms.
 .RE
 .\" METHOD: copy
 .TP
@@ -274,81 +326,108 @@ error.
 .TP
 \fBchan create \fImode cmdPrefix\fR
 .
-Creates a new channel, called a \fBreflected\fR channel, with \fIcmdPrefix\fR
-as its handler, and returns the name of the channel.  \fBcmdPrefix\fR is the
-first words of a command that provides the interface for a \fBrefchan\fR.
+This subcommand creates a new script level channel using the command
+prefix \fIcmdPrefix\fR as its handler. Any such channel is called a
+\fBreflected\fR channel. The specified command prefix, \fBcmdPrefix\fR,
+must be a non-empty list, and should provide the API described in the
+\fBrefchan\fR manual page. The handle of the new channel is
+returned as the result of the \fBchan create\fR command, and the
+channel is open. Use either \fBclose\fR or \fBchan close\fR to remove
+the channel.
 .RS
 .PP
-\fBImode\fR is a list of one or more of the strings
+The argument \fImode\fR specifies if the new channel is opened for
+reading, writing, or both. It has to be a list containing any of the
+strings
 .QW \fBread\fR
 or
 .QW \fBwrite\fR ,
-indicating whether the channel is a read channel, a write channel, or both.
-It is an error if the handler does not support the chosen mode.
-.PP
-The handler is called as needed from the global namespace at the top level, and
-command resolution happens there at the time of the call.  If the handler is
-renamed or deleted any subsequent attempt to call it is an error, which may
-not be able to describe the failure.
-.PP
-The handler is always called in the interpreter and thread it was created in,
-even if the channel was shared with or moved into a different interpreter in a
-different thread.  This is achieved through event dispatch, so if the event
-loop is not entered, e.g. by calling \fBTcl_DoOneEvent\fR or \fBvwait\fR or
-using Tk, the thread performing the channel operation \fIblocks
-indefinitely\fR, resulting in deadlock.
-.PP
-One side of a channel may be in one thread while the other side is in a
-different thread, providing a stream-oriented bridge between the threads. This
-provides a method for regular stream communication between threads as an
-alternative to sending commands.
-.PP
-When the interpreter the handler is in is deleted each channel associated with
-the handler is deleted as well, regardless of which interpreter or thread it
-is currently in or shared with.
-.PP
-\fBchan create\fR is \fBsafe\fR and is accessible to safe interpreters.  The
-handler is always called in the safe interpreter it was created in.
+The list must have at least one
+element, as a channel you can neither write to nor read from makes no
+sense. The handler command for the new channel must support the chosen
+mode, or an error is thrown.
+.PP
+The command prefix is executed in the global namespace, at the top of
+call stack, following the appending of arguments as described in the
+\fBrefchan\fR manual page. Command resolution happens at the
+time of the call. Renaming the command, or destroying it means that
+the next call of a handler method may fail, causing the channel
+command invoking the handler to fail as well. Depending on the
+subcommand being invoked, the error message may not be able to explain
+the reason for that failure.
+.PP
+Every channel created with this subcommand knows which interpreter it
+was created in, and only ever executes its handler command in that
+interpreter, even if the channel was shared with and/or was moved into
+a different interpreter. Each reflected channel also knows the thread
+it was created in, and executes its handler command only in that
+thread, even if the channel was moved into a different thread. To this
+end all invocations of the handler are forwarded to the original
+thread by posting special events to it. This means that the original
+thread (i.e. the thread that executed the \fBchan create\fR command)
+must have an active event loop, i.e. it must be able to process such
+events. Otherwise the thread sending them will \fIblock
+indefinitely\fR. Deadlock may occur.
+.PP
+Note that this permits the creation of a channel whose two endpoints
+live in two different threads, providing a stream-oriented bridge
+between these threads. In other words, we can provide a way for
+regular stream communication between threads instead of having to send
+commands.
+.PP
+When a thread or interpreter is deleted, all channels created with
+this subcommand and using this thread/interpreter as their computing
+base are deleted as well, in all interpreters they have been shared
+with or moved into, and in whatever thread they have been transferred
+to. While this pulls the rug out under the other thread(s) and/or
+interpreter(s), this cannot be avoided. Trying to use such a channel
+will cause the generation of a regular error about unknown channel
+handles.
+.PP
+This subcommand is \fBsafe\fR and made accessible to safe
+interpreters.  While it arranges for the execution of arbitrary Tcl
+code the system also makes sure that the code is always executed
+within the safe interpreter.
 .RE
 .\" METHOD: eof
 .TP
-\fBchan eof \fIchannelName\fR
+\fBchan eof \fIchannelId\fR
 .
-Returns 1 if the last read on the channel failed because the end of the data
-was already reached, and 0 otherwise.
+Test whether the last input operation on the channel called
+\fIchannelId\fR failed because the end of the data stream was reached,
+returning 1 if end-of-file was reached, and 0 otherwise.
 .\" METHOD: event
 .TP
-\fBchan event \fIchannelName event\fR ?\fIscript\fR?
+\fBchan event \fIchannelId event\fR ?\fIscript\fR?
 .
-Arranges for the given script, called a \fBchannel event handler\fR, to be
-called whenever the given event, one of
-.QW \fBreadable\fR
-or
-.QW \fBwritable\fR
-occurs on the given channel, replacing any script that was previously set.  If
-\fIscript\fR is the empty string the current handler is deleted.  It is also
-deleted when the channel is closed.  If \fIscript\fR is omitted, either the
-existing script or the empty string is returned.  The event loop must be
-entered, e.g. via \fBvwait\fR or \fBupdate\fR, or by using Tk, for handlers to
-be evaluated.
+Arrange for the Tcl script \fIscript\fR to be installed as a \fIfile
+event handler\fR to be called whenever the channel called
+\fIchannelId\fR enters the state described by \fIevent\fR (which must
+be either \fBreadable\fR or \fBwritable\fR); only one such handler may
+be installed per event per channel at a time.  If \fIscript\fR is the
+empty string, the current handler is deleted (this also happens if the
+channel is closed or the interpreter deleted).  If \fIscript\fR is
+omitted, the currently installed script is returned (or an empty
+string if no such handler is installed).  The callback is only
+performed if the event loop is being serviced (e.g. via \fBvwait\fR or
+\fBupdate\fR).
 .RS
 .PP
-\fIscript\fR is evaluated at the global level in the interpreter it was
-established in.  Any resulting error is handled in the background, i.e. via
-\fBinterp bgerror\fR.  In order to prevent an endless loop due to a buggy
-handler, the handler is deleted if \fIscript\fR returns an error so that it is
-not evaluated again.
-.PP
-Without an event handler, \fBchan gets\fR or \fBchan read\fR on a channel in
-blocking mode may block until data becomes available, during which the
-thread is unable to perform other work or respond to events on other channels.
-This could cause the application to appear to
+A file event handler is a binding between a channel and a script, such
+that the script is evaluated whenever the channel becomes readable or
+writable.  File event handlers are most commonly used to allow data to
+be received from another process on an event-driven basis, so that the
+receiver can continue to interact with the user or with other channels
+while waiting for the data to arrive.  If an application invokes
+\fBchan gets\fR or \fBchan read\fR on a blocking channel when there is
+no input data available, the process will block; until the input data
+arrives, it will not be able to service other events, so it will
+appear to the user to
 .QW "freeze up"
 \&.
-Channel event handlers allow events on the channel to direct channel handling
-so that the reader or writer can continue to perform other processing while
-waiting for a channel to become available and then handle channel operations
-when the channel is ready for the operation.
+With \fBchan event\fR, the
+process can tell when data is present and only invoke \fBchan gets\fR
+or \fBchan read\fR when they will not block.
 .PP
 A channel is considered to be readable if there is unread data
 available on the underlying device.  A channel is also considered to
@@ -364,29 +443,47 @@ there is no special check for end of file, an infinite loop may occur
 where \fIscript\fR reads no data, returns, and is immediately invoked
 again.
 .PP
-A channel is considered to be writable if at least one byte of data can be
-written to the underlying file or device without blocking, or if an error
-condition is present. Note that client sockets opened in asynchronous mode
-become writable when they become connected or if the connection fails.
-.PP
-Event-driven channel handling works best for channels in non-blocking mode.  A
-channel in blocking mode blocks when \fBchan puts\fR writes more data than the
-channel can accept at the moment, and when \fBchan gets\fR or \fBchan read\fR
-requests more data than is currently available.  When a channel blocks, the
-thread can not do any other processing or service any other events.  A channel
-in non-blocking mode allows a thread to carry on with other work and get back
-to the channel at the right time.
+A channel is considered to be writable if at least one byte of data
+can be written to the underlying file or device without blocking, or
+if an error condition is present on the underlying file or device.
+Note that client sockets opened in asynchronous mode become writable
+when they become connected or if the connection fails.
+.PP
+Event-driven I/O works best for channels that have been placed into
+non-blocking mode with the \fBchan configure\fR command.  In blocking
+mode, a \fBchan puts\fR command may block if you give it more data
+than the underlying file or device can accept, and a \fBchan gets\fR
+or \fBchan read\fR command will block if you attempt to read more data
+than is ready; no events will be processed while the commands block.
+In non-blocking mode \fBchan puts\fR, \fBchan read\fR, and \fBchan
+gets\fR never block.
+.PP
+The script for a file event is executed at global level (outside the
+context of any Tcl procedure) in the interpreter in which the \fBchan
+event\fR command was invoked.  If an error occurs while executing the
+script then the command registered with \fBinterp bgerror\fR is used
+to report the error.  In addition, the file event handler is deleted
+if it ever returns an error; this is done in order to prevent infinite
+loops due to buggy handlers.
 .RE
 .\" METHOD: flush
 .TP
-\fBchan flush \fIchannelName\fR
+\fBchan flush \fIchannelId\fR
 .
-For a channel in blocking mode, flushes all buffered output to the destination,
-and then returns.  For a channel in non-blocking mode, returns immediately
-while all buffered output is flushed in the background as soon as possible.
+Ensures that all pending output for the channel called \fIchannelId\fR
+is written.
+.RS
+.PP
+If the channel is in blocking mode the command does not return until
+all the buffered output has been flushed to the channel. If the
+channel is in non-blocking mode, the command may return before all
+buffered output has been flushed; the remainder will be flushed in the
+background as fast as the underlying file or device is able to absorb
+it.
+.RE
 .\" METHOD: gets
 .TP
-\fBchan gets \fIchannelName\fR ?\fIvarName\fR?
+\fBchan gets \fIchannelId\fR ?\fIvarName\fR?
 .
 Reads a line from the channel consisting of all characters up to the next
 end-of-line sequence or until end of file is seen. The line feed character
@@ -434,126 +531,142 @@ changing the encoding in use. See \fBENCODING ERROR EXAMPLES\fR later.
 .TP
 \fBchan names\fR ?\fIpattern\fR?
 .
-Returns a list of all channel names, or if \fIpattern\fR is given, only those
-names that match according to the rules of \fBstring match\fR.
+Produces a list of all channel names. If \fIpattern\fR is specified,
+only those channel names that match it (according to the rules of
+\fBstring match\fR) will be returned.
 .\" METHOD: pending
 .TP
-\fBchan pending \fImode channelName\fR
+\fBchan pending \fImode channelId\fR
 .
-Returns the number of bytes of input
-when \fImode\fR is
-.QW\fBinput\fR
-, or output when \fImode\fR is
-.QW\fBoutput\fR
-, that are currently internally buffered for the channel.  Useful in a readable
-event callback to impose limits on input line length to avoid a potential
-denial-of-service attack where an extremely long line exceeds the available
-memory to buffer it.  Returns -1 if the channel was not opened for the mode in
-question.
+Depending on whether \fImode\fR is \fBinput\fR or \fBoutput\fR,
+returns the number of
+bytes of input or output (respectively) currently buffered
+internally for \fIchannelId\fR (especially useful in a readable event
+callback to impose application-specific limits on input line lengths to avoid
+a potential denial-of-service attack where a hostile user crafts
+an extremely long line that exceeds the available memory to buffer it).
+Returns -1 if the channel was not opened for the mode in question.
 .\" METHOD: pipe
 .TP
 \fBchan pipe\fR
 .
-Creates a pipe, i.e. a readable channel and a writable channel, and returns the
-names of the readable channel and the writable channel.  Data written to the
-writable channel can be read from the readable channel.  Because the pipe is a
-real system-level pipe, it can be connected to other processes using
-redirection.  For example, to redirect \fBstderr\fR from a subprocess into one
-channel, and \fBstdout\fR into another, \fBexec\fR with "2>@" and ">@", each
-onto the writable side of a pipe, closing the writable side immediately
-thereafter so that EOF is signaled on the read side once the subprocess has
-closed its output, typically on exit.
+Creates a standalone pipe whose read- and write-side channels are
+returned as a 2-element list, the first element being the read side and
+the second the write side. Can be useful e.g. to redirect
+separately \fBstderr\fR and \fBstdout\fR from a subprocess. To do
+this, spawn with "2>@" or
+">@" redirection operators onto the write side of a pipe, and then
+immediately close it in the parent. This is necessary to get an EOF on
+the read side once the child has exited or otherwise closed its output.
 .RS
 .PP
-Due to buffering, data written to one side of a pipe might not immediately
-become available on the other side.  Tcl's own buffers can be configured via
-\fBchan configure -buffering\fR, but overall behaviour still depends on
-operating system buffers outside of Tcl's control. Once the write side of the
-channel is closed, any data remaining in the buffers is flushed through to the
-read side.  It may be useful to arrange for the connected process to flush at
-some point after writing to the channel or to have it use some system-provided
-mechanism to configure buffering.  When two pipes are connected to the same
-process, one to send data to the process, and one to read data from the
-process, a deadlock may occur if the channels are in blocking mode:  If
-reading, the channel may block waiting for data that can never come because
-buffers are only flushed on subsequent writes, and if writing, the channel may
-block while waiting for the buffers to become free, which can never happen
-because the reader can not read while the writer is blocking.  To avoid this
-issue, either put the channels into non-blocking mode and use event handlers,
-or place the read channel and the write channel in separate interpreters in
-separate threads.
+Note that the pipe buffering semantics can vary at the operating system level
+substantially; it is not safe to assume that a write performed on the output
+side of the pipe will appear instantly to the input side. This is a
+fundamental difference and Tcl cannot conceal it. The overall stream semantics
+\fIare\fR compatible, so blocking reads and writes will not see most of the
+differences, but the details of what exactly gets written when are not. This
+is most likely to show up when using pipelines for testing; care should be
+taken to ensure that deadlocks do not occur and that potential short reads are
+allowed for.
 .RE
 .\" METHOD: pop
 .TP
-\fBchan pop \fIchannelName\fR
+\fBchan pop \fIchannelId\fR
 .
-Removes the topmost transformation handler from the channel if there is one,
-and closes the channel otherwise. The result is normally the empty string, but
-may be an error in some situations, e.g. when closing the underlying resource
-results in an error.
+Removes the topmost transformation from the channel \fIchannelId\fR, if there
+is any. If there are no transformations added to \fIchannelId\fR, this is
+equivalent to \fBchan close\fR of that channel. The result is normally the
+empty string, but can be an error in some situations (i.e. where the
+underlying system stream is closed and that results in an error).
 .\" METHOD: postevent
 .TP
-\fBchan postevent \fIchannelName eventSpec\fR
+\fBchan postevent \fIchannelId eventSpec\fR
 .
-For use by handlers established with \fBchan create\fR.  Notifies Tcl that
-that one or more event(s) listed in \fIeventSpec\fR, each of which is either
-.QW\fBread\fR
-or
-.QW\fBwrite\fR.
-, have occurred.
+This subcommand is used by command handlers specified with \fBchan
+create\fR. It notifies the channel represented by the handle
+\fIchannelId\fR that the event(s) listed in the \fIeventSpec\fR have
+occurred. The argument has to be a list containing any of the strings
+\fBread\fR and \fBwrite\fR. The list must contain at least one
+element as it does not make sense to invoke the command if there are
+no events to post.
 .RS
 .PP
-For use only by handlers for a channel created by \fBchan create\fR.  It is an
-error to post an event for any other channel.
-.PP
-Since only the handler for a reflected channel channel should post events it is
-an error to post an event from any interpreter other than the interpreter that
-created the channel.
-.PP
-It is an error to post an event that the channel has no interest in.  See
-\fBwatch\fR in the \fBrefchan\fR documentation for more information
-.PP
-\fBchan postevent\fR is available in safe interpreters, as any handler for a
-reflected channel would have been created, and will be evaluated in that
-interpreter as well.
+Note that this subcommand can only be used with channel handles that
+were created/opened by \fBchan create\fR. All other channels will
+cause this subcommand to report an error.
+.PP
+As only the Tcl level of a channel, i.e. its command handler, should
+post events to it we also restrict the usage of this command to the
+interpreter that created the channel. In other words, posting events
+to a reflected channel from an interpreter that does not contain it's
+implementation is not allowed. Attempting to post an event from any
+other interpreter will cause this subcommand to report an error.
+.PP
+Another restriction is that it is not possible to post events that the
+I/O core has not registered an interest in. Trying to do so will cause
+the method to throw an error. See the command handler method
+\fBwatch\fR described in \fBrefchan\fR, the document specifying
+the API of command handlers for reflected channels.
+.PP
+This command is \fBsafe\fR and made accessible to safe interpreters.
+It can trigger the execution of \fBchan event\fR handlers, whether in the
+current interpreter or in other interpreters or other threads, even
+where the event is posted from a safe interpreter and listened for by
+a trusted interpreter. \fBChan event\fR handlers are \fIalways\fR
+executed in the interpreter that set them up.
 .RE
 .\" METHOD: push
 .TP
-\fBchan push \fIchannelName cmdPrefix\fR
+\fBchan push \fIchannelId cmdPrefix\fR
 .
-Adds a new transformation handler on top of the channel and returns a handle
-for the transformation.  \fIcmdPrefix\fR is the first words of a command that
-provides the interface documented for \fBtranschan\fR, and transforms data on
-the channel, It is an error if handler does not support the mode(s) the channel
-is in.
+Adds a new transformation on top of the channel \fIchannelId\fR. The
+\fIcmdPrefix\fR argument describes a list of one or more words which represent
+a handler that will be used to implement the transformation. The command
+prefix must provide the API described in the \fBtranschan\fR manual page.
+The result of this subcommand is a handle to the transformation. Note that it
+is important to make sure that the transformation is capable of supporting the
+channel mode that it is used with or this can make the channel neither
+readable nor writable.
 .\" METHOD: puts
 .TP
-\fBchan puts\fR ?\fB\-nonewline\fR? ?\fIchannelName\fR? \fIstring\fR
+\fBchan puts\fR ?\fB\-nonewline\fR? ?\fIchannelId\fR? \fIstring\fR
 .
-Writes \fIstring\fR and a line feed to the channel.  If \fB\-nonewline\fR is
-given, the trailing line feed is not written. The default channel is
+Writes \fIstring\fR to the channel named \fIchannelId\fR followed by a
+newline character. A trailing newline character is written unless the
+optional flag \fB\-nonewline\fR is given. If \fIchannelId\fR is
+omitted, the string is written to the standard output channel,
 \fBstdout\fR.
 .RS
 .PP
-Each line feed in the output is translated to the appropriate end of line
-sequence as per the \fB\-translation\fR configuration setting of the channel.
-.PP
-Because Tcl internally buffers output, characters written to a channel may not
-immediately be available at the destination.  Tcl normally delays output until
-the buffer is full or the channel is closed. \fBchan flush\fR forces output in
-the direction of the destination.
-.PP
-When the output for a channel in blocking mode fills up, \fBchan puts\fR blocks
-until space in the buffer is available again. On the other hand for a channel in
-non-blocking mode, it returns immediately and the data is written in the
-background as fast possible, constrained by the speed at which as the
-destination accepts it. Output to a channel in non-blocking mode only works
-properly when the application enters the event loop. When a channel is in
-non-blocking mode, Tcl's internal buffers can hold an arbitrary amount of data,
-possibly consuming a large amount of memory. To avoid wasting memory, channels
-in non-blocking mode should normally be handled using \fBchan event\fR, where
-the application only invokes \fBchan puts\fR after being notified through a file
-event handler that the channel is ready for more output data.
+Newline characters in the output are translated by \fBchan puts\fR to
+platform-specific end-of-line sequences according to the currently
+configured value of the \fB\-translation\fR option for the channel
+(for example, on PCs newlines are normally replaced with
+carriage-return-linefeed sequences; see \fBchan configure\fR above for
+details).
+.PP
+Tcl buffers output internally, so characters written with \fBchan
+puts\fR may not appear immediately on the output file or device; Tcl
+will normally delay output until the buffer is full or the channel is
+closed.  You can force output to appear immediately with the \fBchan
+flush\fR command.
+.PP
+When the output buffer fills up, the \fBchan puts\fR command will
+normally block until all the buffered data has been accepted for
+output by the operating system.  If \fIchannelId\fR is in non-blocking
+mode then the \fBchan puts\fR command will not block even if the
+operating system cannot accept the data.  Instead, Tcl continues to
+buffer the data and writes it in the background as fast as the
+underlying file or device can accept it.  The application must use the
+Tcl event loop for non-blocking output to work; otherwise Tcl never
+finds out that the file or device is ready for more output data.  It
+is possible for an arbitrarily large amount of data to be buffered for
+a channel in non-blocking mode, which could consume a large amount of
+memory.  To avoid wasting memory, non-blocking I/O should normally be
+used in an event-driven fashion with the \fBchan event\fR command
+(do not invoke \fBchan puts\fR unless you have recently been notified
+via a file event that the channel is ready for more output data).
 .PP
 The command will raise an error exception with POSIX error code \fBEILSEQ\fR if
 the encoding profile \fBstrict\fR is in effect for the channel and the output
@@ -562,34 +675,58 @@ may be partially written to the channel in this case.
 .RE
 .\" METHOD: read
 .TP
-\fBchan read \fIchannelName\fR ?\fInumChars\fR?
+\fBchan read \fIchannelId\fR ?\fInumChars\fR?
 .TP
-\fBchan read \fR?\fB\-nonewline\fR? \fIchannelName\fR
+\fBchan read \fR?\fB\-nonewline\fR? \fIchannelId\fR
 .
-Reads and returns the next \fInumChars\fR characters from the channel. If
-\fInumChars\fR is omitted, all available characters up to the end of the file
-are read, or if the channel is in non-blocking mode, all currently-available
-characters are read.  If there is an error on the channel, reading ceases and
-an error is returned.  If \fInumChars\fR is not given, \fB\-nonewline\fR
-may be given, causing any trailing line feed to be trimmed.
+In the first form, the result will be the next \fInumChars\fR
+characters read from the channel named \fIchannelId\fR; if
+\fInumChars\fR is omitted, all characters up to the point when the
+channel would signal a failure (whether an end-of-file, blocked or
+other error condition) are read. In the second form (i.e. when
+\fInumChars\fR has been omitted) the flag \fB\-nonewline\fR may be
+given to indicate that any trailing newline in the string that has
+been read should be trimmed.
 .RS
 .PP
-If the channel is in non-blocking mode, fewer characters than requested may be
-returned.  If the channel is configured to use a multi-byte encoding, bytes
-that do not form a complete character are retained in the buffers until enough
-bytes to complete the character accumulate, or the end of the data is reached.
-\fB\-nonewline\fR is ignored if characters are returned before reaching the end
-of the file.
+If \fIchannelId\fR is in non-blocking mode, \fBchan read\fR 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 \fB\-nonewline\fR switch is ignored if
+the command returns before reaching the end of the file.
+.PP
+\fBChan read\fR translates end-of-line sequences in the input into
+newline characters according to the \fB\-translation\fR option for the
+channel (see \fBchan configure\fR above for a discussion on the ways
+in which \fBchan configure\fR will alter input).
 .PP
-Each end-of-line sequence according to the value of \fB\-translation\fR is
-translated into a line feed.
+When reading from a serial port, most applications should configure
+the serial port channel to be non-blocking, like this:
 .PP
-When reading from a serial port, most applications should configure the serial
-port channel to be in non-blocking mode, but not necessarily use an event
-handler since most serial ports are comparatively slow.  It is entirely
-possible to get a \fBreadable\fR event for each individual character.  In
-blocking mode, \fBchan read\fR blocks forever when reading to the end of the
-data if there is no \fBchan configure -eofchar\fR configured for the channel.
+.CS
+\fBchan configure \fIchannelId \fB\-blocking \fI0\fR.
+.CE
+.PP
+Then \fBchan read\fR behaves much like described above.  Note that
+most serial ports are comparatively slow; it is entirely possible to
+get a \fBreadable\fR event for each character read from them. Care
+must be taken when using \fBchan read\fR on blocking serial ports:
+.TP
+\fBchan read \fIchannelId numChars\fR
+.
+In this form \fBchan read\fR blocks until \fInumChars\fR have been
+received from the serial port.
+.TP
+\fBchan read \fIchannelId\fR
+.
+In this form \fBchan read\fR blocks until the reception of the
+end-of-file character, see \fBchan configure -eofchar\fR. If there no
+end-of-file character has been configured for the channel, then
+\fBchan read\fR will block forever.
 .PP
 If the encoding profile \fBstrict\fR is in effect for the channel, the command
 will raise an exception with the POSIX error code \fBEILSEQ\fR if any encoding
@@ -608,41 +745,56 @@ changing the encoding in use. See \fBENCODING ERROR EXAMPLES\fR later.
 .RE
 .\" METHOD: seek
 .TP
-\fBchan seek \fIchannelName offset\fR ?\fIorigin\fR?
+\fBchan seek \fIchannelId offset\fR ?\fIorigin\fR?
 .
-Sets the current position for the data in the channel to integer \fIoffset\fR
-bytes relative to \fIorigin\fR.  A negative offset moves the current position
-backwards from the origin.  \fIorigin\fR is one of the
-following:
+Sets the current access position within the underlying data stream for
+the channel named \fIchannelId\fR to be \fIoffset\fR bytes relative to
+\fIorigin\fR. \fIOffset\fR must be an integer (which may be negative)
+and \fIorigin\fR must be one of the following:
 .RS
 .IP \fBstart\fR
-The origin is the start of the data.  This is the default.
+The new access position will be \fIoffset\fR bytes from the start
+of the underlying file or device.
 .IP \fBcurrent\fR
-The origin is the current position.
+The new access position will be \fIoffset\fR bytes from the current
+access position; a negative \fIoffset\fR moves the access position
+backwards in the underlying file or device.
 .IP \fBend\fR
-The origin is the end of the data.
-.PP
-\fBChan seek\fR flushes all buffered output even if the channel is in
-non-blocking mode, discards any buffered and unread input, and returns the
-empty string or an error if the channel does not support seeking.
-.PP
-\fIoffset\fR values are byte offsets, not character offsets.  Unlike \fBchan
-read\fR, both \fBchan seek\fR and \fBchan tell\fR operate in terms of bytes,
-not characters,
+The new access position will be \fIoffset\fR bytes from the end of the
+file or device.  A negative \fIoffset\fR places the access position
+before the end of file, and a positive \fIoffset\fR places the access
+position after the end of file.
+.PP
+The \fIorigin\fR argument defaults to \fBstart\fR.
+.PP
+\fBChan seek\fR flushes all buffered output for the channel before the
+command returns, even if the channel is in non-blocking mode.  It also
+discards any buffered and unread input.  This command returns an empty
+string.  An error occurs if this command is applied to channels whose
+underlying file or device does not support seeking.
+.PP
+Note that \fIoffset\fR values are byte offsets, not character offsets.
+Both \fBchan seek\fR and \fBchan tell\fR operate in terms of bytes,
+not characters, unlike \fBchan read\fR.
 .RE
 .\" METHOD: tell
 .TP
-\fBchan tell \fIchannelName\fR
+\fBchan tell \fIchannelId\fR
 .
-Returns the offset in bytes of the current position in the underlying data, or
--1 if the channel does not support seeking. The value can be passed to \fBchan
-seek\fR to set current position to that offset.
+Returns a number giving the current access position within the
+underlying data stream for the channel named \fIchannelId\fR. This
+value returned is a byte offset that can be passed to \fBchan seek\fR
+in order to set the channel to a particular position.  Note that this
+value is in terms of bytes, not characters like \fBchan read\fR.  The
+value returned is -1 for channels that do not support seeking.
 .\" METHOD: truncate
 .TP
-\fBchan truncate \fIchannelName\fR ?\fIlength\fR?
+\fBchan truncate \fIchannelId\fR ?\fIlength\fR?
 .
-Flushes the channel and truncates the data in the channel to \fIlength\fR
-bytes, or to the current position in bytes if \fIlength\fR is omitted.
+Sets the byte length of the underlying data stream for the channel
+named \fIchannelId\fR to be \fIlength\fR (or to the current byte
+offset within the underlying data stream if \fIlength\fR is
+omitted). The channel is flushed before truncation.
 .
 .SH EXAMPLES
 .SS "SIMPLE CHANNEL OPERATION EXAMPLES"
@@ -753,7 +905,7 @@ preventing servicing of other connections at the same time:
 .PP
 .CS
 # This is a very simple logger...
-proc log message {
+proc log {message} {
     \fBchan puts\fR stdout $message
 }
 
@@ -876,7 +1028,7 @@ full line.
 .CS
 % set f [open test_A_195_B.txt r]
 file384b6a8
-% chan configure $f -encoding utf-8 -profile strict
+% chan configure $f -encoding utf-8
 % catch {chan gets $f} e d
 1
 % set d
@@ -886,7 +1038,7 @@ file384b6a8
 -errorinfo {...} -errorline 1
 % chan tell $f
 0
-% chan configure $f -encoding binary -profile strict
+% chan configure $f -encoding binary
 % chan gets $f
 AÃB
 .CE
@@ -900,7 +1052,7 @@ position 1. The data at the error position is thus recovered by the next
 .CS
 % set f [open test_A_195_B.txt r]
 file35a65a0
-% chan configure $f -encoding utf-8 -profile strict -blocking 1
+% chan configure $f -encoding utf-8 -blocking 1
 % catch {chan read $f} e d
 1
 % set d
@@ -910,7 +1062,7 @@ file35a65a0
 -errorinfo {...} -errorline 1
 % chan tell $f
 1
-% chan configure $f -encoding binary -profile strict
+% chan configure $f -encoding binary
 % chan read $f
 ÃB
 % chan close $f
@@ -921,7 +1073,7 @@ Finally the same example, but this time with a non-blocking channel.
 .CS
 % set f [open test_A_195_B.txt r]
 file35a65a0
-% chan configure $f -encoding utf-8 -profile strict -blocking 0
+% chan configure $f -encoding utf-8 -blocking 0
 % chan read $f
 A
 % chan tell $f