Re: tee command incompatible with xterm
Re: tee command incompatible with xterm
- Subject: Re: tee command incompatible with xterm
- From: Marquette Jean-Baptiste <email@hidden>
- Date: Sun, 04 Dec 2011 11:59:41 +0100
Hi Cameron,
Thanks for the comment. An additional reason to replace the tee command by the more convenient xterm internal logging options.
Cheers
JB
Le 3 déc. 2011 à 23:27, Cameron Simpson a écrit :
> On 02Dec2011 22:12, Marquette Jean-Baptiste <email@hidden> wrote:
> | Le 2 déc. 2011 à 21:08, email@hidden a écrit :
> | > why use a tee command from within an xterm given xterm itself can
> | > send a copy of all its output to a log file?
> |
> |
> | Because I didn't know that option! I modified my command to use -l -lf,
> | and the results are far better¿
>
> Just as a remark, Jean-Baptiste is probably being bitten by buffering.
>
> Tee itself is unbuffered because it is made to sit in pipelines to copy
> data as it happens. However, most commands buffer their output (stdout;
> stderr by convention is unbuffered in order to see error messages
> promptly).
>
> When output is a terminal the stdio package line buffers by default,
> producing human friendly behaviour. But other, output is _block_
> buffered, and only sent when the buffer is full (eg every 8192 bytes).
>
> When you run a command in an xterm like this:
>
> foo
>
> its output is connected to the terminal provided by xterm, and line
> buffering takes place.
>
> When you run this:
>
> foo | tee bah
>
> the output of "foo" is not a terminal, and it block buffered.
> "tee" is copying data immediately, but "foo" is only sending it when the
> buffer fills, not when a line fills.
>
> But dropping "tee" and using xterm's logging facility you are causing
> "foo" to have a terminal again. But if your command was like this:
>
> foo | bah
>
> foo would again be block buffering, even if you were using xterm's
> logging stuff.
>
> Just so you all realise _why_ you see what you see,
> --
> Cameron Simpson <email@hidden> DoD#743
> http://www.cskk.ezoshosting.com/cs/
>
> DRM doesn't inconvenience pirates ¿ indeed, over time it trains
> law-abiding users to become pirates out of sheer frustration.
> - Charles Stross
_______________________________________________
Do not post admin requests to the list. They will be ignored.
X11-users mailing list (email@hidden)
This email sent to email@hidden