[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RFE: stat(1) flag for learning the d_type value of a given file

From: Eric Blake
Subject: RFE: stat(1) flag for learning the d_type value of a given file
Date: Mon, 13 Oct 2014 13:56:31 -0600
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1

The Cygwin developers have been trying to improve some d_type hints
given during readdir(), to return DT_DIR instead of DT_UNKNOWN for
obvious directories, as an example.  But testing the patches for
correctness has proved to be a bit of a challenge for testing.  On an
IRC chat, we discovered that it is really difficult to find out what
d_type lists for a given file without using a debugger or writing a
custom program - most GNU code is using it as an optimization to avoid
lstat(), but never directly outputs that the optimization took place.
So the idea was raised: could we teach stat(1) a new format arg that
would make it painfully obvious what d_type hint is associated with a
given file?

Of course, such a format is not trivial, and must not be part of the
default stat output.  Given 'stat --format=... a', you'd have to do
readdir() on "." until you find "a", in order to get to the d_type.  But
I couldn't think of any better utility to enhance to easily get at
d_type information from the shell.  At least, stat(1) feels like a
better choice than ls(1) for adding the enhanced output information.

What do you think? Should I spend time writing up a patch?

Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library

Attachment: signature.asc
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]