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Diffstat (limited to 'doc/tell.n')
| -rw-r--r-- | doc/tell.n | 32 |
1 files changed, 3 insertions, 29 deletions
@@ -16,36 +16,10 @@ tell \- Return current access position for an open channel .BE .SH DESCRIPTION .PP -Returns an integer giving the current access position in -\fIchannelId\fR. This value returned is a byte offset that can be passed to -\fBseek\fR in order to set the channel to a particular position. Note -that this value is in terms of bytes, not characters like \fBread\fR. -The value returned is -1 for channels that do not support -seeking. -.PP -\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. -.SH EXAMPLE -.PP -Read a line from a file channel only if it starts with \fBfoobar\fR: -.PP -.CS -# Save the offset in case we need to undo the read... -set offset [\fBtell\fR $chan] -if {[read $chan 6] eq "foobar"} { - gets $chan line -} else { - set line {} - # Undo the read... - seek $chan $offset -} -.CE +The \fBtell\fR command has been superceded by the \fBchan tell\fR +command which supports the same syntax and options. .SH "SEE ALSO" -file(n), open(n), close(n), gets(n), seek(n), Tcl_StandardChannels(3) -.SH KEYWORDS -access position, channel, seeking +chan(n) '\" Local Variables: '\" mode: nroff '\" fill-column: 78 |