tail does not exit

Mikhail Teterin mi+mill at aldan.algebra.com
Wed Dec 19 16:33:00 PST 2007


Max N. Boyarov:
>       -f      The -f option causes tail to not stop when end of file is
>              reached, but rather to wait for additional data to be appended
> to the input.  The -f option is ignored if the standard input is a pipe,
> but not if it is a FIFO.

Josh Tolbert:
> Cause the -f option to tail doesn't work that way. -f always waits for more
> input.

I know very well about -f waiting for more *input*. What puzzles me, is that 
tail does not quit, when its *output* is closed.

James Harrison:
> Is there a reason you want the -f flag?

Yes, I want awk to be processing the lines, which are appended to the file, 
until it finds, what it is looking for, and exits. I expect tail to go away, 
when its stdout is closed, but it does not.

> tail -f holds on for dear life until a ctrl-c happens. IT HAS A DEATH
> GRIP!

This seems like a bug to me... It should hold on to its input file(s), but 
exit peacefully, when its stdout closes. No?

 -mi


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