On 09/07/2007, at 3:18 PM, Amos Shapira wrote:
On 09/07/07, Jeff Waugh <[EMAIL PROTECTED]> wrote:
<quote who="Amos Shapira">
>> Zhasper> find . -name "<junkfile>" -print0 | xargs -0 rm
>>
>> Actually lighter weight, less forking less execing, because this
version
>> runs two procsses only, rather than a new invocation of rm for
each
file
>> found.
>
> It runs at least three processes if it finds any file - "rm" is
forked
> from xargs (unless xargs is smart enough to save the fork on end of
> input?)
No, three in total (in common circumstances): One for find, one
for xargs,
one for rm. It will invoke more than one rm process if xargs
determins
that
the parameter length is too long for a single invocation (or if other
params
altering that behaviour are passed to it, unlike the example
provided).
So an enhancement suggestion I have for xargs is that when it
reaches EOF on
its input it can skip the "fork" and just "exec" the command given
to it
("rm" in the case above). That is, unless there is some xargs
option that
requires it to stay behind even the last command (I can't find any
from a
cursory look at "man xargs"). I suppose you can look at this as
another form
of "tail recursion optimization".
Maybe I'll get around to implement this one day...
I think you have to fork, otherwise xargs will not be able to
guarantee that it returns a documented error code.
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