Beyond Linux® From Scratch - Version 2012-01-16

Chapter 4. Security

attr-2.4.44

Introduction to attr

The attr package contains utilities to administer the extended attributes on filesystem objects.

This package is known to build and work properly using an LFS-7.0 platform.

Package Information

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/attr

Installation of attr

Install attr by running the following commands: 

cat > test/sort-getfattr-output << "EOF" &&
#! /usr/bin/perl -w
undef $/;
print join("\n\n", sort split(/\n\n/, <>)), "\n\n";
EOF

chmod 755 test/sort-getfattr-output &&
sed -i -e 's|/@pkg_name@|&-@pkg_version@|' \
       -e 's|@prefix|$(DESTDIR)&|'         \
       -e 's|@libexec|$(DESTDIR)&|'        \
    include/builddefs.in &&

./configure --prefix=/usr --libexecdir=/usr/lib &&
make

There are three sets of tests that come with this package. Issue the following to execute all three: make tests root-tests ext-tests. For meaningful results, the tests need to be carried out on a file system that supports extended attributes.

Now, as the root user: 

make install install-dev install-lib &&
chmod -v 755 /usr/lib/libattr.{so.1.1.0,la}         &&
chown -v root.root /usr/lib/libattr.{a,la,so.1.1.0} &&
chown -v root.root /usr/share/man/man*/*attr*

Command Explanations

cat > test/sort-getfattr-output ... EOF: This command creates a missing test script.

sed ... include/builddefs.in: This command modifies the documentation directory so that it is a versioned directory and also adds support for a DESTDIR installation.

chmod ...: This command modifies the permissions of installed library files to standards.

Configuring attr

Configuration Information

There is no configuration to attr itself, but to get any use out of attr, a filesystem needs to support extended attributes.

One way to achieve this is to add the user_xattr option to an ext3 filesystem in the /etc/fstab file as shown below: 

# file system  mount-point  type   options                 dump  fsck
#                                                                order

/dev/sda1      /            ext3   defaults,acl,user_xattr 0     2

Contents

Installed Programs: attr, getfattr, and setfattr
Installed Library: libattr.{so,a}
Installed Directories: /usr/{include/attr,share/doc/attr-2.4.44}

Short Descriptions

attr

extends attributes on filesystem objects.

getfattr

gets the extended attributes of filesystem objects.

setfattr

sets the extended attributes of filesystem objects.

libattr.{so,a}

contains the attr API functions.

Last updated on 2011-10-25 03:31:31 +0000