Correct Answers :

[B]

Explanation :

“PS/2” can refer to both a hardware interface and a software protocol, but used in the context of the Protocol option, it unambiguously refers to the software protocol. Thus, option B is correct.
Option A might be correct, but the specifi ed line is insuffi cient evidence of that; USB mice generally use the PS/2 protocol or a variant of it, such as the Intellimouse PS/2 protocol. Although the PS/2 hardware port and protocol originated with the IBM PS/2 computer mentioned in option C, many other computers now use them.
Mice that use the PS/2 protocol may be used with just about any OS, not just IBM’s OS/2, so option D is incorrect. A slash (/) is valid as part of the PS/2 protocol name, so option E is incorrect.

Correct Answers :

[A, C]

Explanation :

Examining a process listing (obtained from ps) for signs of the super server is the most reliable way to determine which one is actually running, so option A is correct.
The presence of the super server’s configuration file or files (as in option C) is also a good diagnostic, although some older systems that have been upgraded may have both sets of configuration files. There is no standard superserver utility to report on which one is used,so option B is incorrect.
Most distributions launch the super server through a SysV startup script; the /etc/inittab file isn’t directly involved in this process, so examining it would be pointless, and option D is incorrect. Although the output of netstat -ap, when typed as root, will include an indication of any instance of inetd or xinetd that’s listening for connections, option E omits the critical -p option, which causes the program to display process names. Thus, option E is incorrect.

Correct Answers :

[D]

Explanation :

The lpc utility is used to start, stop, change the priority of, and otherwise control jobs in a print queue. CUPS ships with an lpc utility, but it’s quite rudimentary compared to the lpc utilities of BSD LPD and LPRng. Instead, CUPS relies on its Web-based interface to provide the ability to control print jobs. Thus, option D is correct, and the remaining options must logically all be incorrect.

Correct Answers :

[C]

Explanation :

The /etc/security/limits.conf file defi nes various limits on user resources, including the number of simultaneous logins individual users are permitted. Thus, option C is correct. The /etc/pam.d/login-limits file (option A) is fictitious, although login limits do rely on the pam_limits module to the Pluggable Authentication System (PAM).
The /etc/bashrc file (option B) is a global bash startup script file, but it’s not normally used to impose login limits.
The /etc/inittab file (option D) is a key Linux startup file, but it doesn’t have any direct bearing on imposing login limits. The /etc/passwd file (option E) defi nes many key account features, but login limits are not among these

Correct Answers :

[C, D]

Explanation :

The computer’s IP address (option C) and network mask (aka subnet mask or netmask; option D) are the most critical components in TCIP/IP network configuration. (Additional information you may need to provide on many networks includes the IP addresses of one to three DNS servers, the hostname or IP address of a router, and the computer’s hostname.) You shouldn’t need the IP address of a Dynamic Host configuration Protocol (DHCP) server (option A)—and if a DHCP server is present, chances are you should be using DHCP rather than static IP address assignment.
A NetBIOS Name Service (NBNS) server (option B) converts between names and IP addresses on NetBIOS networks. The hostname of such a computer isn’t likely to be a critical configuration element, although you may need to provide this information to Samba for some operations to function correctly when sharing files. A Network Time Protocol (NTP) server (option E) helps you maintain system time on all your computers, but this isn’t required for basic network configuration.

Correct Answers :

[E]

Explanation :

The wc command displays a count of newlines, words, and bytes in the specifi ed file (report.txt). Piping this data through tee causes a copy of the output to be stored in the new file (wc in this example—you shouldn’t run this command in the same directory as the wc executable file!).
Thus, option E is correct. Contrary to option A, wc is not an editor, and the remaining syntax wouldn’t cause two files to open in separate windows even if wc were an editor. Contrary to option B, wc doesn’t count windows or open a new window.
Option C describes the effect of wc report | wc—that is, it overlooks the tee command. Contrary to option D, wc has nothing to do with cleaning up memory leaks, and tee doesn’t directly use the report.txt file.

Correct Answers :

[C]

Explanation :

The grub.cfg filename indicates a GRUB 2 configuration file. In such files, each OS or kernel stanza begins with a menuentry line and an open curly brace ({) and ends with a close curly brace (}). Thus, option C is correct.
Some configuration files and programming languages use semicolons (;) at the end of most lines, but this isn’t true of GRUB 2, so option A is incorrect.
Although close parentheses ()) are used to terminate some types of options in some configuration files, including disk identifi ers in GRUB 2’s configuration file, they aren’t used to terminate whole OS or kernel definitions in this file, so option B is incorrect. The string */ terminates comments in C program files, but isn’t commonly used in GRUB 2 configuration files, so option D is incorrect.
Option E would be correct if the question had asked about a GRUB Legacy configuration file (menu.lst or grub.conf), but the question specifi es a GRUB 2 configuration file (grub.cfg); the two boot loaders terminate their OS/kernel stanzas differently, so option E is incorrect

Correct Answers :

[E]

Explanation :

The third field of /etc/passwd entries holds the UID number for the account, so option E is correct. Linux doesn’t use any standard identifier called a human ID (HID; option A), although the acronym HID stands for human interface device, a class of USB devices. Accounts don’t have PID numbers (option B); those belong to running processes.
The account’s GID number (option C) is stored in the fourth fi eld of /etc/passwd—100 in this example. Linux accounts don’t use globally unique ID (GUID) numbers, so option D is incorrect.

Correct Answers :

[B]

Explanation :

The grep command scans files to find those that contain a specified string or pattern, as described by option B. In the case of text files, grep displays the matching line or lines; for binary files, it reports that the file matches the pattern.
The method of creating a pipeline (option A) involves separating two commands with a vertical bar (|). The grep command can be used in a pipeline, but it doesn’t create one. The command that concatenates files (option C) is cat, and the command that displays the last several lines of a fi le (option D)

Correct Answers :

[B, D, E]

Explanation :

ReiserFS (option B) was written from scratch for Linux. The Third Extended Filesystem (ext3fs; option D) is a journaling filesystem based on the older non-journaling Second Extended Filesystem (ext2fs; option C). The Extents Filesystem (XFS; option E) is a journaling filesystem written by SGI for Irix and later ported to Linux. The High- Performance Filesystem (HPFS; option A) is a non-journaling filesystem designed by Microsoft for OS/2.

Correct Answers :

[A]

Explanation :

Option A correctly describes the features of SSH and GPG in this context. Option B is incorrect because SSH should do a fine job of encrypting your email so that it can’t be decoded between your system and your ISP’s email server.
Option C has it backward; email transferred via SSH will be completely encrypted, including both headers and body. GPG doesn’t encrypt headers, just message bodies.
Option D is incorrect because GPG isn’t a virus scanner, just an encryption tool. Option E is incorrect because the SSH tunnel will encrypt everything in the SMTP transfer, including email attachments.

Correct Answers :

[A, D]

Explanation :

Port 110 (option A) is assigned to the Post Offi ce Protocol (POP), and port 143 (option D) is assigned to the Internet Message Access Protocol (IMAP), both of which may be used to retrieve email messages from an email server system.
Port 119 (option B) is assigned to the Network News Transfer Protocol (NNTP), port 139 (option C) is assigned to the Server Message Block/Common Internet File System (SMB/CIFS) protocol, and port 443 (option E) is assigned to the Hypertext Transfer Protocol with SSL encryption (HTTPS), none of which is commonly used for email retrieval.

Correct Answers :

[C]

Explanation :

Log files, such as /var/log/messages and sometimes others in /var/log, often contain useful information concerning server errors. The tail program displays the last few lines of a fi le, so using it to examine log files immediately after a problem occurs can be a useful diagnostic procedure. Option C correctly combines these features.
The http:// localhost:631 URL of option A accesses the Common Unix Printing System (CUPS) confi guration utility, which has nothing to do with SSH. There is no standard diagnose utility (option B) to help diagnose server problems, and there is no standard /dev/ssh fi le (option D). The sshd program is the SSH server itself, so option B will simply launch the server.

Correct Answers :

[B]

Explanation :

The ~./profile fi le is one of several bash startup scripts, as stated in option B. It has nothing to do with the ProFTP server (option A) or the tcsh shell (option D). The ProFile fi le manager mentioned in option C is fictitious. Users’ encrypted passwords (option E) are usually stored in /etc/shadow.

Correct Answers :

[E]

Explanation :

The at utility was created to run programs at one specifi ed point in the future. Thus, option E will accomplish the stated goal. Options A and C might also work; but neither is the best way to accomplish this goal. Option A will tie up CPU time, and if the program crashes or the system is shut down during the intervening two years, the message will never display. Option C would be more reliable, but it adds unnecessary complexity to your hourly cron job schedule.
The cal program displays a text-mode calendar, enabling you to identify the days of a week for a given month; it doesn’t schedule future jobs, as option B suggests. A GUI calendar program, as specifi ed in option D, might work; but NTP is the Network Time Protocol, a protocol and like-named program for synchronizing clocks across a network. Thus, NTP isn’t the tool for the job, and option D is incorrect..

Correct Answers :

[D]

Explanation :

Option D provides the correct command to add 172.24.21.1 as the default gateway. Options A and B both use the fictitious gateway command, which doesn’t exist and therefore won’t work unless you create a script of this name. Option C uses the correct route command, but there is no gateway option to route; you must use add default gw, as in option D. There is no standard gw command, so option E is incorrect.

Correct Answers :

[B, C]

Explanation :

The BRLTTY package is an add-on daemon for handling a Braille display device, and some features for using these devices have been added to the 2.6.26 kernel, so options B and C are correct. Emacspeak (option A) is speech-synthesis software; it can be used to “speak” a text display to a user, but it doesn’t interface with Braille displays. GOK (option D) is an on-screen keyboard, not a Braille display tool. Framebuffer drivers (option E) are kernel drivers for managing conventional video cards; they aren’t used to drive Braille displays.

Correct Answers :

[C]

Explanation :

Some dependencies result from dynamically linking binaries to libraries at compile time and so can be overcome by recompiling the software from a source RPM, so option C is correct. Option A describes Debian source packages, not RPM packages.
Recompiling a source RPM requires only issuing an appropriate command, although you must also have appropriate compilers and libraries installed.
Thus, option B is overly pessimistic. Source tarballs can also be used to compile software for RPM systems, although this results in none of RPM’s advantages. Thus, option D is overly restrictive. The RPM format doesn’t impose any licensing requirements, contrary to option E.

Correct Answers :

[D]

Explanation :

The mv utility can be used to rename files as well as move them from one location to another, so option D is correct. The dd utility (option A) is used to copy files to backups, rm (option B) is used to remove (delete) files, cp (option C) copies files, and ln (option E) creates links.

Correct Answers :

[B]

Explanation :

Appending an ampersand (&) to a command causes that command to execute in the background. The program so launched still consumes CPU time, but it won’t monopolize the shell you used to launch it. Thus, option B is correct. The start (option A) and background (option D) commands are fictitious.
Although bg (option C) does place a job into the background, it doesn’t launch a program that way; it places a process that’s been suspended (by pressing Ctrl+Z) into the background. The nice utility (option E) launches a program with modifi ed priority, but a program so launched still monopolizes its shell unless you take additional steps.