[Coco] Re: Using that 16/32/64 MB RamDrive.
Rodney V Hamilton
Rodney_Hamilton at GBRonline.com
Sun Feb 8 09:18:11 EST 2004
In article <EFEDDBF1-5A03-11D8-A69A-000A95AFE1F0 at concentric.net>,
alxevans at concentric.net says...
>On Feb 7, 2004, at 1:01 PM, William Astle wrote:
>> On Sat, 7 Feb 2004, Gene Heskett wrote:
>>> As a matter of fact, I got rather dissappointed in other OS's because
>>> I couldn't do that, not with amigaos, nor with linux, although I
>>> haven't really tried that hard or recently in linux. But, time goes
>>> only forward.
>> You have, of course, investigated the "tail" command? Should work on
>> about any unix variant.
>Different variants of Unix provide varying levels of file sharing. On
>some variants including early versions of Linux do not permit you to
>read a file which is open for writing by another process. I believe
>that this is permitted in current versions of Linux. Even in those
>versions which do permit this will give you different results from
>OS-9. In OS-9 if you attempt to read past the end of a file which is
>currently being written by another process the reading process will
>block until the file has been written to that point, or the writing
>process closes the file. In Unix (assuming that you can open the file
>for reading in the first place) it will react as if the end of the file
>is at the point where it has been lat written to. Some of us (myself,
>Gene, and perhaps others) miss the OS-9 manner of handling this. The
>"tail" command is of no help in this.
That's why tail had a '-f' (follow) option. That would make tail
go into an endless loop at the end of the input file, wherein it
would sleep for a second and try to read any additional data that
may have been appended, until tail was killed. This was commonly
used to monitor the growth of a file being written by another task.
The Linux version of tail also has a '-s' option to set the number
of seconds to wait with the '-f' option. [man tail]
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