Calling cygpath from find exec?

Calling cygpath from find exec?

[Matt D.]

Is there a reason why these produce different results?

find . -exec cygpath -wa {} \;
find . -exec echo $(cygpath -wa {}) \;

I have to do this which is much slower:
find . -exec bash -c 'echo $(cygpath -wa {})' \;

Or this:
find . | while read a; do echo $(cygpath -wa $a); done


Matt D.

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RE: Calling cygpath from find exec?

[Nellis, Kenneth]

From: Matt D.
> 
> Is there a reason why these produce different results?
> 
> find . -exec cygpath -wa {} \;
> find . -exec echo $(cygpath -wa {}) \;
> 
> I have to do this which is much slower:
> find . -exec bash -c 'echo $(cygpath -wa {})' \;
> 
> Or this:
> find . | while read a; do echo $(cygpath -wa $a); done

How about the following?

find . | cygpath -waf-

--Ken Nellis

Re: Calling cygpath from find exec?

[Eric Blake]

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On 11/23/2015 01:45 PM, Matt D. wrote:
> Is there a reason why these produce different results?
> 
> find . -exec cygpath -wa {} \;
> find . -exec echo $(cygpath -wa {}) \;

Incorrect quoting.  You are invoking:

find . -exec echo c:\cygwin\home\you\{} \;

(or whatever ./{} resolves to), instead of one cygpath per name found by
find.

> 
> I have to do this which is much slower:
> find . -exec bash -c 'echo $(cygpath -wa {})' \;
> 

This indeed quotes things so that cygpath is now invoked once per file,
but at the expense of an additional bash per file as well.

Why not just:

find . -exec cygpath -wa {} +

since cygpath handles more than one file in an invocation (that is,
using '-exec {} +' rather than '-exec {} \;' is generally faster).

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: Calling cygpath from find exec?

[Duncan Roe]

On Mon, Nov 23, 2015 at 02:23:33PM -0700, Eric Blake wrote:
> On 11/23/2015 01:45 PM, Matt D. wrote:
> > Is there a reason why these produce different results?
> >
> > find . -exec cygpath -wa {} \;
> > find . -exec echo $(cygpath -wa {}) \;
>
> Incorrect quoting.  You are invoking:
>
> find . -exec echo c:\cygwin\home\you\{} \;
>
> (or whatever ./{} resolves to), instead of one cygpath per name found by
> find.
>
> >
> > I have to do this which is much slower:
> > find . -exec bash -c 'echo $(cygpath -wa {})' \;
> >
>
> This indeed quotes things so that cygpath is now invoked once per file,
> but at the expense of an additional bash per file as well.
>
> Why not just:
>
> find . -exec cygpath -wa {} +
>
> since cygpath handles more than one file in an invocation (that is,
> using '-exec {} +' rather than '-exec {} \;' is generally faster).
>
I would be using xargs. Especially under /cygdrive, the "-print0 / xargs -0"
combination takes care of spaces and other nasties in file names.

find . -print0 | xargs -0 cygpath -wa

For utilities that only accept one argument, you can use xargs -n1 -0; you
still get the benefit of -print0.

Cheers ... Duncan.

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Re: Calling cygpath from find exec?

[Eric Blake]

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On 12/01/2015 01:43 PM, Duncan Roe wrote:

>> Why not just:
>>
>> find . -exec cygpath -wa {} +
>>
>> since cygpath handles more than one file in an invocation (that is,
>> using '-exec {} +' rather than '-exec {} \;' is generally faster).
>>
> I would be using xargs. Especially under /cygdrive, the "-print0 / xargs -0"
> combination takes care of spaces and other nasties in file names.

But so does 'find ... -exec ... {} +', and with one fewer process.
xargs is fine when you need it, but here, you don't.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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