| '\" |
| '\" Copyright (c) 1993 The Regents of the University of California. |
| '\" Copyright (c) 1994-1997 Sun Microsystems, Inc. |
| '\" |
| '\" See the file "license.terms" for information on usage and redistribution |
| '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
| '\" |
| '\" RCS: @(#) $Id: fcopy.n,v 1.3 2001/05/19 16:59:04 andreas_kupries Exp $ |
| '\" |
| '\" The definitions below are for supplemental macros used in Tcl/Tk |
| '\" manual entries. |
| '\" |
| '\" .AP type name in/out ?indent? |
| '\" Start paragraph describing an argument to a library procedure. |
| '\" type is type of argument (int, etc.), in/out is either "in", "out", |
| '\" or "in/out" to describe whether procedure reads or modifies arg, |
| '\" and indent is equivalent to second arg of .IP (shouldn't ever be |
| '\" needed; use .AS below instead) |
| '\" |
| '\" .AS ?type? ?name? |
| '\" Give maximum sizes of arguments for setting tab stops. Type and |
| '\" name are examples of largest possible arguments that will be passed |
| '\" to .AP later. If args are omitted, default tab stops are used. |
| '\" |
| '\" .BS |
| '\" Start box enclosure. From here until next .BE, everything will be |
| '\" enclosed in one large box. |
| '\" |
| '\" .BE |
| '\" End of box enclosure. |
| '\" |
| '\" .CS |
| '\" Begin code excerpt. |
| '\" |
| '\" .CE |
| '\" End code excerpt. |
| '\" |
| '\" .VS ?version? ?br? |
| '\" Begin vertical sidebar, for use in marking newly-changed parts |
| '\" of man pages. The first argument is ignored and used for recording |
| '\" the version when the .VS was added, so that the sidebars can be |
| '\" found and removed when they reach a certain age. If another argument |
| '\" is present, then a line break is forced before starting the sidebar. |
| '\" |
| '\" .VE |
| '\" End of vertical sidebar. |
| '\" |
| '\" .DS |
| '\" Begin an indented unfilled display. |
| '\" |
| '\" .DE |
| '\" End of indented unfilled display. |
| '\" |
| '\" .SO |
| '\" Start of list of standard options for a Tk widget. The |
| '\" options follow on successive lines, in four columns separated |
| '\" by tabs. |
| '\" |
| '\" .SE |
| '\" End of list of standard options for a Tk widget. |
| '\" |
| '\" .OP cmdName dbName dbClass |
| '\" Start of description of a specific option. cmdName gives the |
| '\" option's name as specified in the class command, dbName gives |
| '\" the option's name in the option database, and dbClass gives |
| '\" the option's class in the option database. |
| '\" |
| '\" .UL arg1 arg2 |
| '\" Print arg1 underlined, then print arg2 normally. |
| '\" |
| '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $ |
| '\" |
| '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. |
| .if t .wh -1.3i ^B |
| .nr ^l \n(.l |
| .ad b |
| '\" # Start an argument description |
| .de AP |
| .ie !"\\$4"" .TP \\$4 |
| .el \{\ |
| . ie !"\\$2"" .TP \\n()Cu |
| . el .TP 15 |
| .\} |
| .ta \\n()Au \\n()Bu |
| .ie !"\\$3"" \{\ |
| \&\\$1 \\fI\\$2\\fP (\\$3) |
| .\".b |
| .\} |
| .el \{\ |
| .br |
| .ie !"\\$2"" \{\ |
| \&\\$1 \\fI\\$2\\fP |
| .\} |
| .el \{\ |
| \&\\fI\\$1\\fP |
| .\} |
| .\} |
| .. |
| '\" # define tabbing values for .AP |
| .de AS |
| .nr )A 10n |
| .if !"\\$1"" .nr )A \\w'\\$1'u+3n |
| .nr )B \\n()Au+15n |
| .\" |
| .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n |
| .nr )C \\n()Bu+\\w'(in/out)'u+2n |
| .. |
| .AS Tcl_Interp Tcl_CreateInterp in/out |
| '\" # BS - start boxed text |
| '\" # ^y = starting y location |
| '\" # ^b = 1 |
| .de BS |
| .br |
| .mk ^y |
| .nr ^b 1u |
| .if n .nf |
| .if n .ti 0 |
| .if n \l'\\n(.lu\(ul' |
| .if n .fi |
| .. |
| '\" # BE - end boxed text (draw box now) |
| .de BE |
| .nf |
| .ti 0 |
| .mk ^t |
| .ie n \l'\\n(^lu\(ul' |
| .el \{\ |
| .\" Draw four-sided box normally, but don't draw top of |
| .\" box if the box started on an earlier page. |
| .ie !\\n(^b-1 \{\ |
| \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| .\} |
| .el \}\ |
| \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
| .\} |
| .\} |
| .fi |
| .br |
| .nr ^b 0 |
| .. |
| '\" # VS - start vertical sidebar |
| '\" # ^Y = starting y location |
| '\" # ^v = 1 (for troff; for nroff this doesn't matter) |
| .de VS |
| .if !"\\$2"" .br |
| .mk ^Y |
| .ie n 'mc \s12\(br\s0 |
| .el .nr ^v 1u |
| .. |
| '\" # VE - end of vertical sidebar |
| .de VE |
| .ie n 'mc |
| .el \{\ |
| .ev 2 |
| .nf |
| .ti 0 |
| .mk ^t |
| \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' |
| .sp -1 |
| .fi |
| .ev |
| .\} |
| .nr ^v 0 |
| .. |
| '\" # Special macro to handle page bottom: finish off current |
| '\" # box/sidebar if in box/sidebar mode, then invoked standard |
| '\" # page bottom macro. |
| .de ^B |
| .ev 2 |
| 'ti 0 |
| 'nf |
| .mk ^t |
| .if \\n(^b \{\ |
| .\" Draw three-sided box if this is the box's first page, |
| .\" draw two sides but no top otherwise. |
| .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| .\} |
| .if \\n(^v \{\ |
| .nr ^x \\n(^tu+1v-\\n(^Yu |
| \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c |
| .\} |
| .bp |
| 'fi |
| .ev |
| .if \\n(^b \{\ |
| .mk ^y |
| .nr ^b 2 |
| .\} |
| .if \\n(^v \{\ |
| .mk ^Y |
| .\} |
| .. |
| '\" # DS - begin display |
| .de DS |
| .RS |
| .nf |
| .sp |
| .. |
| '\" # DE - end display |
| .de DE |
| .fi |
| .RE |
| .sp |
| .. |
| '\" # SO - start of list of standard options |
| .de SO |
| .SH "STANDARD OPTIONS" |
| .LP |
| .nf |
| .ta 5.5c 11c |
| .ft B |
| .. |
| '\" # SE - end of list of standard options |
| .de SE |
| .fi |
| .ft R |
| .LP |
| See the \\fBoptions\\fR manual entry for details on the standard options. |
| .. |
| '\" # OP - start of full description for a single option |
| .de OP |
| .LP |
| .nf |
| .ta 4c |
| Command-Line Name: \\fB\\$1\\fR |
| Database Name: \\fB\\$2\\fR |
| Database Class: \\fB\\$3\\fR |
| .fi |
| .IP |
| .. |
| '\" # CS - begin code excerpt |
| .de CS |
| .RS |
| .nf |
| .ta .25i .5i .75i 1i |
| .. |
| '\" # CE - end code excerpt |
| .de CE |
| .fi |
| .RE |
| .. |
| .de UL |
| \\$1\l'|0\(ul'\\$2 |
| .. |
| .TH fcopy n 8.0 Tcl "Tcl Built-In Commands" |
| .BS |
| '\" Note: do not modify the .SH NAME line immediately below! |
| .SH NAME |
| fcopy \- Copy data from one channel to another. |
| .SH SYNOPSIS |
| \fBfcopy \fIinchan\fR \fIoutchan\fR ?\fB\-size \fIsize\fR? ?\fB\-command \fIcallback\fR? |
| .BE |
| |
| .SH DESCRIPTION |
| .PP |
| The \fBfcopy\fP command copies data from one I/O channel, \fIinchan\fR to another I/O channel, \fIoutchan\fR. |
| The \fBfcopy\fP command leverages the buffering in the Tcl I/O system to |
| avoid extra copies and to avoid buffering too much data in |
| main memory when copying large files to slow destinations like |
| network sockets. |
| .PP |
| The \fBfcopy\fP |
| command transfers data from \fIinchan\fR until end of file |
| or \fIsize\fP bytes have been |
| transferred. If no \fB\-size\fP argument is given, |
| then the copy goes until end of file. |
| All the data read from \fIinchan\fR is copied to \fIoutchan\fR. |
| Without the \fB\-command\fP option, \fBfcopy\fP blocks until the copy is complete |
| and returns the number of bytes written to \fIoutchan\fR. |
| .PP |
| The \fB\-command\fP argument makes \fBfcopy\fP work in the background. |
| In this case it returns immediately and the \fIcallback\fP is invoked |
| later when the copy completes. |
| The \fIcallback\fP is called with |
| one or two additional |
| arguments that indicates how many bytes were written to \fIoutchan\fR. |
| If an error occurred during the background copy, the second argument is the |
| error string associated with the error. |
| With a background copy, |
| it is not necessary to put \fIinchan\fR or \fIoutchan\fR into |
| non-blocking mode; the \fBfcopy\fP command takes care of that automatically. |
| However, it is necessary to enter the event loop by using |
| the \fBvwait\fP command or by using Tk. |
| .PP |
| You are not allowed to do other I/O operations with |
| \fIinchan\fR or \fIoutchan\fR during a background fcopy. |
| If either \fIinchan\fR or \fIoutchan\fR get closed |
| while the copy is in progress, the current copy is stopped |
| and the command callback is \fInot\fP made. |
| If \fIinchan\fR is closed, |
| then all data already queued for \fIoutchan\fR is written out. |
| .PP |
| Note that \fIinchan\fR can become readable during a background copy. |
| You should turn off any \fBfileevent\fP handlers during a background |
| copy so those handlers do not interfere with the copy. |
| Any I/O attempted by a \fBfileevent\fP handler will get a "channel busy" error. |
| .PP |
| \fBFcopy\fR translates end-of-line sequences in \fIinchan\fR and \fIoutchan\fR |
| according to the \fB\-translation\fR option |
| for these channels. |
| See the manual entry for \fBfconfigure\fR for details on the |
| \fB\-translation\fR option. |
| The translations mean that the number of bytes read from \fIinchan\fR |
| can be different than the number of bytes written to \fIoutchan\fR. |
| Only the number of bytes written to \fIoutchan\fR is reported, |
| either as the return value of a synchronous \fBfcopy\fP or |
| as the argument to the callback for an asynchronous \fBfcopy\fP. |
| .PP |
| \fBFcopy\fR obeys the encodings configured for the channels. This |
| means that the incoming characters are converted internally first |
| UTF-8 and then into the encoding of the channel \fBfcopy\fR writes |
| to. See the manual entry for \fBfconfigure\fR for details on the |
| \fB\-encoding\fR option. No conversion is done if both channels are |
| set to encoding "binary". If only the output channel is set to |
| encoding "binary" the system will write the internal UTF-8 |
| representation of the incoming characters. If only the input channel |
| is set to encoding "binary" the system will assume that the incoming |
| bytes are valid UTF-8 characters and convert them according to the |
| output encoding. The behaviour of the system for bytes which are not |
| valid UTF-8 characters is undefined in this case. |
| |
| .SH EXAMPLE |
| .PP |
| This first example shows how the callback gets |
| passed the number of bytes transferred. |
| It also uses vwait to put the application into the event loop. |
| Of course, this simplified example could be done without the command |
| callback. |
| .DS |
| proc Cleanup {in out bytes {error {}}} { |
| global total |
| set total $bytes |
| close $in |
| close $out |
| if {[string length $error] != 0} { |
| # error occurred during the copy |
| } |
| } |
| set in [open $file1] |
| set out [socket $server $port] |
| fcopy $in $out -command [list Cleanup $in $out] |
| vwait total |
| |
| .DE |
| .PP |
| The second example copies in chunks and tests for end of file |
| in the command callback |
| .DS |
| proc CopyMore {in out chunk bytes {error {}}} { |
| global total done |
| incr total $bytes |
| if {([string length $error] != 0) || [eof $in] { |
| set done $total |
| close $in |
| close $out |
| } else { |
| fcopy $in $out -command [list CopyMore $in $out $chunk] \\ |
| -size $chunk |
| } |
| } |
| set in [open $file1] |
| set out [socket $server $port] |
| set chunk 1024 |
| set total 0 |
| fcopy $in $out -command [list CopyMore $in $out $chunk] -size $chunk |
| vwait done |
| |
| .DE |
| |
| .SH "SEE ALSO" |
| eof(n), fblocked(n), fconfigure(n) |
| |
| .SH KEYWORDS |
| blocking, channel, end of line, end of file, nonblocking, read, translation |