X-Git-Url: http://git.osdn.net/view?a=blobdiff_plain;f=tcl%2Fdoc%2Fseek.n;fp=tcl%2Fdoc%2Fseek.n;h=7b156db5242fcc2f9b595a2ff52d955f47673ad2;hb=ae4bf010374a9320497af260fa90af3fe8e2c5a5;hp=0000000000000000000000000000000000000000;hpb=3cc729069938336ea54d399c4bbbe7d197295f9a;p=pf3gnuchains%2Fpf3gnuchains3x.git diff --git a/tcl/doc/seek.n b/tcl/doc/seek.n new file mode 100644 index 0000000000..7b156db524 --- /dev/null +++ b/tcl/doc/seek.n @@ -0,0 +1,70 @@ +'\" +'\" Copyright (c) 1993 The Regents of the University of California. +'\" Copyright (c) 1994-1996 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: @(#) $Id$ +'\" +.so man.macros +.TH seek n 8.1 Tcl "Tcl Built-In Commands" +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +seek \- Change the access position for an open channel +.SH SYNOPSIS +\fBseek \fIchannelId offset \fR?\fIorigin\fR? +.BE + +.SH DESCRIPTION +.PP +Changes the current access position for \fIchannelId\fR. +.PP +.VS +\fIChannelId\fR must be an identifier for an open channel such as a +Tcl standard channel (\fBstdin\fR, \fBstdout\fR, or \fBstderr\fR), +the return value from an invocation of \fBopen\fR or \fBsocket\fR, or +the result of a channel creation command provided by a Tcl extension. +.VE +.PP +The \fIoffset\fR and \fIorigin\fR +arguments specify the position at which the next read or write will occur +for \fIchannelId\fR. \fIOffset\fR must be an integer (which may be +negative) and \fIorigin\fR must be one of the following: +.TP 10 +\fBstart\fR +The new access position will be \fIoffset\fR bytes from the start +of the underlying file or device. +.TP 10 +\fBcurrent\fR +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. +.TP 10 +\fBend\fR +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. +.LP +The \fIorigin\fR argument defaults to \fBstart\fR. +.PP +The command flushes all buffered output for the channel before the command +returns, even if the channel is in nonblocking 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 +.VS 8.1 +Note that \fIoffset\fR values are byte offsets, not character +offsets. Both \fBseek\fR and \fBtell\fR operate in terms of bytes, +not characters, unlike \fBread\fR. +.VE 8.1 + +.SH "SEE ALSO" +file(n), open(n), close(n), gets(n), tell(n), Tcl_StandardChannels(3) + +.SH KEYWORDS +access position, file, seek