U

UIDs (user IDs)

about, 32, 816

NFS and, 281s

SUID permissions, 32–33

umask command, 32, 816

umask file, 287

umask group settings, 302, 303

umount.cifs command, 522, 809

Unix-type operating systems

development of Linux from, 444

Red Hat differences from, 3

Samba's interoperability between

Windows and, 519

tips for administrators of, 255

unmounting and remounting filesystems, 17

up2date

automatic dependency resolution with, 237

yum command replacing, 693

updatedb command, 21, 23

updating

dependency resolution and RPM, 237

GRUB, 150–152

grub.conf file, 391–392

kernels, 226–227, 379

packages with yum command, 242

with Pup, 236

software in first boot, 124

upgrading

kernels, 389–390

RPMs, 224

URLs

access via lftp command, 51–53

accessing with text or graphical browser, 50–51

USB devices

Linux support for, 78

sharing IRQs, 5

USB key

booting from installation, 91–92

creating installation, 89–90

mounting, 201–203

using automounter with, 207

USB ports, 5

used-based security for Apache, 460–461

User Access tab (Add NFS Share dialog), 500–501

user administration. See also users

command line tools for, 274–277, 283–284

managing user environment, 285–287

overview of, 272

Red Hat User Manager, 277–280

self test and answers, 321–322, 324–325

shell configuration files, 287–290

summarized, 317–318

tips for managing user accounts, 280–281

two-minute drill, 319–320

working with special groups, 301–305

user IDs, 275

user interface. See also command line; GUI; X Window System

CUPS Web-based, 349–351

display managers, 663

User Mapping options (SELinux Management Tool), 715

user private groups

configuring ownership and permissions for Samba home directory, 531

creating group Samba directory, 532–533

Red Hat scheme for, 280–281, 301

User Properties dialog (Red Hat User Manager), 282, 283

useradd command, 276, 277

usermod command, 283, 816

users. See also root user account; UIDs

about, 31–32

adding, 273, 274–275, 276, 277, 279–280

Apache user-based security, 460–461

assigning password for, 276–277

authenticating network, 313–317

categories of, 273–274

checking for authorized, 305–313

configuring in first boot process, 124

configuring Samba, 539–540

creating in vi, 10–11

deleting, 281

disk quotas for, 290–301

errors running yum command from local system, 239

including in groups, 275–276

limiting access to su and sudo commands, 284–285

logging in for exam as root, 273

managing, 280–281, 283–284, 534–535

modifying, 281–283

POP, 589

securing with tcp_wrappers, 694–696

security levels for, 693

superusers, 34, 815

using corresponding Samba and Windows, 529, 533

/usr/src/linux directory, 393–394

/usr/src/redhat directory, 231

uucp, 586