Correct Answers :

[A, B]

Explanation :

The -Uvh parameter issues an upgrade command (which installs the program whether or not an earlier version is installed) and creates a series of hash marks to display the command’s progress. The -i parameter installs the program if it’s not already installed but causes no progress display. Option C uses a package name, not a complete filename, and so it will fail to install the package file. The -e option removes a package.

Correct Answers :

[B]

Explanation :

Option B, fsck, is Linux’s filesystem check utility. It’s similar in purpose to the DOS and Windows CHKDSK and ScanDisk utilities, but these DOS and Windows utilities don’t work on Linux filesystems like ext2fs or ReiserFS. Option A, mkfs, creates new filesystems; it doesn’t diagnose or fix filesystem problems.

Correct Answers :

[A]

Explanation :

A freshly installed MySQL database is unlikely to have a ready-made database of animals, so your first task is to create that database with the CREATE DATABASE command, as shown in option A. (You could call the database something other than animals, of course.) The USE command in option B will only be useful once the database has been created. Once the database is created, you can use CREATE TABLE, as in option C, to create a table; but you’ll need an existing database first, and this command also requires information about the type of data to be stored, which option C doesn’t provide. Option D’s INSERT INTO command stores data into a table once it’s been created, so it’s far from the first command you’ll use. It also requires additional specification of the data to be stored, so it’s incomplete.

Correct Answers :

[B, D]

Explanation :

The correct answers, man and info, are two common Linux help packages. Although ? is a common help command within certain interactive programs, it isn’t a help command in bash or other common Linux shells.

Correct Answers :

[A, C]

Explanation :

Unix systems traditionally store time in UTC (a.k.a. Greenwich Mean Time), and Linux may do so as well. Most other x86 PC OSs traditionally store time as the local time however, so Linux also supports this option. Internet Time is an alternative to the 24-hour clock in which the day is broken into 1,000 “beats.” Standard PC BIOSs don’t support this time format. Likewise, a 12-hour clock isn’t terribly useful to computers because it doesn’t differentiate a.m. from p.m.

Correct Answers :

[D]

Explanation :

Typing lsmod produces a list of the modules that are currently loaded. The insmod and modprobe programs both load modules—either a single module or a single module and all those on which it depends, respectively. The depmod command generates the modules.dep file that contains module dependency information.

Correct Answers :

[B, D]

Explanation :

The chgrp and chown commands can both change the group ownership of a file. The chgrp command takes a group name and a filename as parameters, as in option B. The chown command normally changes a file’s owner; but if you provide a group name preceded by a dot (.), as in option D, it changes the group of a file. The chown command shown in option A will change the primary ownership of the file to the music user, if such a user exists on the system; it won’t change the group ownership. There is no standard chgroup command, as in option C.

Correct Answers :

[A]

Explanation :

Hard links to directories aren’t permitted by most filesystems, so you’ll probably have to create a symbolic link, as noted in option A. Contrary to option B, anybody may create a link, not just the original’s owner. Option C describes a restriction of hard links; but because this link will probably have to be a symbolic link, this restriction is unimportant and option C is incorrect. Option D describes a more severe restriction than option B, but it’s incorrect for the same reasons.

Correct Answers :

[B]

Explanation :

The colon (:) starts ex mode, from which you can enter commands. In ex mode, r includes a file in an existing one, w writes a file, e loads an entirely new file, and q quits the program. Thus, the desired combination is :wq. For more information,

Correct Answers :

[C]

Explanation :

The ~/.forward file is a user e‑mail forwarding file. The vertical bar character (|) at the start of such a file is a code to send the e‑mail through the specified program file, so option C is correct. To do as option A describes, the file would need to read junkme or junkme@hostname, where hostname is the computer’s hostname. To do as option B describes, the leading vertical bar would have to be omitted. It’s conceivable that the ~/junkme script does as option D describes, but there’s no way of knowing this for certain.

Correct Answers :

[D]

Explanation :

Any of these approaches will work, or at least might work. (You might err when performing any of them.) Option B or C is likely to be the most efficient approach; with a long filename to type, option A is likely to be tedious.

Correct Answers :

[B]

Explanation :

The echo command is implemented internally to bash, although an external version is also available on most systems. The cat, tee, and sed commands are not implemented internally to bash, although they can be called from bash as external commands.

Correct Answers :

[D]

Explanation :

The echo command echoes what follows to standard output, and $PROC is an environment variable. Thus, echo $PROC displays the value of the $PROC environment variable, meaning that it must have been set to the specified value by you, one of your configuration files, or a program you’ve run. Although many environment variables are set to particular values to convey information, $PROC isn’t a standard environment variable that might be associated with information described in options A, B, or C.

Correct Answers :

[A]

Explanation :

The pwd command prints (to standard output) the name of the current working directory. The remaining options are simply incorrect, although option B describes the cd command and various tools can be used to reformat wide text for display or printing in fewer columns, as in option C.

Correct Answers :

[D]

Explanation :

The exec command causes the rest of the command to replace the current shell. Thus, when you exit from gedit in this scenario, the result will be the same as if you’d terminated the shell, namely, the xterm window will close. The exec command doesn’t raise the execution privilege, so option A is incorrect. (The su and sudo commands can raise execution privilege, though.) Because the xterm window closes, option B is incorrect. X won’t ordinarily terminate when a single xterm does, and definitely not if that xterm was launched from a window manager, so option C is incorrect.

Correct Answers :

[A]

Explanation :

The dot (.) character refers to the current working directory, and the slash (/) is a directory separator. Thus, preceding a program name by ./ unambiguously identifies the intention to run the program that’s stored in the current directory. Option B will run the first instance of the program that’s found on the current path. Because paths often omit the current directory for security reasons, this option is likely to fail. The run command isn’t a standard Linux command, so option C is unlikely to do anything, much less what the question specifies. Option D would be correct except that it reverses the order of the two characters. The effect is to attempt to run the .myprog file in the root (/) directory. This file probably doesn’t exist, and even if it did, it’s not the file the question specifies should be run.

Correct Answers :

[C]

Explanation :

By default, man uses the less pager to display information on most Linux systems. Although an X-based version of man does exist (xman), the basic man doesn’t use a custom X-based application, nor does it use Firefox or the Vi editor.

Correct Answers :

[C]

Explanation :

The > redirection operator stores a command’s standard output in a file, overwriting the contents of any existing file by the specified name. Option A specifies the standard input redirection so that ifconfig will take the contents of file.txt as input. Option B is almost correct; the >> redirection operator redirects standard output, as requested, but it appends data to the specified file rather than overwriting it. Option D specifies a pipe; the output of ifconfig is sent through the file.txt program, if it exists. (Chances are it doesn’t, so you’d get a command not found error message.)

Correct Answers :

[C]

Explanation :

The &> redirection operator sends both standard output and standard error to the specified file, as option C states. (The name of the file, input.txt, is intentionally deceptive, but the usage is still valid.) Option A mentions standard error but describes it as if it were an input stream, which it’s not; it’s an output stream. Option B mentions standard input, but the &> operator doesn’t affect standard input.

Correct Answers :

[D]

Explanation :

In principle, you can pipe together as many commands as you like. (In practice, of course, there will be limits based on input buffer size, memory, and so on, but these limits are far higher than the 2, 3, or 4 commands specified in options A, B, and C.)