Re: New command consideration - curtail

[Pádraig Brady]

On 08/11/18 09:02, Wolaver, David wrote:
> Hi all,
> 
> I have developed a command line program that I would like to have considered 
> for inclusion in a future revision of coreutils.  The name of the program is 
> "curtail".  It reads stdin and appends to an output file while ensuring that 
> the file will never exceed a specified maximum size.  The main intent is to 
> place a bound on the output of a program such that it cannot create a runaway 
> log file.  The output file is truncated (in multiple of block size) at the 
> beginning such that the output file always contains the latest output of the 
> program.
> 
> user_program | curtail -s 4M output.txt

It's a perfect name for such a command anyway :)

Does this depend on FALLOC_FL_COLLAPSE_RANGE support.
Would this command fail on file systems not supporting this?
Being block based seems a little problematic,
especially considering multi-byte characters,
but maybe that's OK.

cheers,
Pádraig