ITN 171 Exam 2 (Chapters 4-6)
When you no longer need a file, you can delete it using the ____ command. rm remove dl delete
rm
When you no longer need a directory, you can use command ____ to remove it. xtree rmdir dldir deltree
rmdir
____ is NOT a selection command. comm diff grep sed
sed
With no options, ____ displays the current listing of Bash environment and shell script variables. let set sh export
set
When you create a shell script to run in Bash, you can immediately run the script by typing ____ and then the name of the script. run sh start exec
sh
You can use the ____________________ command to sort a file's contents alphabetically or numerically.
sort
If you execute ____, the contents of file1 are sorted and the results are stored in file2. sort file1 -o file2 sort file1 -d file2 sort file1 > file2 sort file1 > file2 sort file1 file2
sort file1 > file2
A program's high-level language statements are stored in a file called the ____ file. shell script program source
source
System administrators and programmers refer to standard input as ____. sin stint stdin standardin
stdin
System administrators and programmers refer to standard output as ____. sout stout stdout standardout
stdout
The paste command normally sends its output to ____. stdout null stderr the file indicated as an argument
stdout
A ____ is a name consisting of letters, numbers, or characters and is used to reference the contents of a variable. comment symbolic name label tag
symbolic name
If a source file contains ____ errors, it cannot be converted into an executable file. syntax debugging compilation logic
syntax
You can use the ____ command to create empty files. touch create make null
touch
The ____ command enables you to initialize the terminal display or terminal window, to place text and prompts in desired locations, and to respond to what the user selects from the menu. put tput clear tclear
tput
What is tr used for?
translates and deletes character by character
The ____ command is useful when you want your shell program to automatically remove any temporary files that are created when the shell script runs. set export tput trap
trap
The ____ command removes duplicate lines from a file. grep dup uniq diff
uniq
____ is a selection command. uniq awk sort sed
uniq
The ____ statement continues to loop and execute commands or statements as long as a given condition or set of conditions is true. for while esac case
while
Match each item with a statement below. 1. environment variable that identifies the path name for user's home directory 2. environment variable that holds the path name of the program for the type of shell you are using 3. environment variable that contains the absolute path to the Bash shell, such as /bin/bash 4. environment variable that holds the primary shell prompt 5. environment variable that contains the file name containing commands to initialize the shell 6. environment variable that holds the list of path names for directories searched for executable commands 7. bitwise negation operator 8. logical negation operator 9. matches exactly one character, except for the backslash and period HOME SHELL BASH PS1 ENV PATH ~ ! ?
1. HOME 2. SHELL 3. BASH 4. PS1 5. ENV 6. PATH 7. ~ 8. ! 9. ?
option of the mv command that overwrites a destination file with the same name, if the source file is newer than the one in the destination paste -i > (gt;) -t -u -d -r -c -name
-u
The ____ option of the grep command displays only lines that do not contain the search pattern. -v -n -o -r
-v
The ____ option of the diff command is used to display the differences side-by-side in columns. -s -c -n -y
-y
One way to run a shell script is to make it executable by using the x permission and then typing ____ prior to the script name when you run the script itself. ./ /. . ..
./
To run the myscript shell script located in the current directory, you should enter: ____. start myscript /.myscript run myscript ./myscript
./myscript
1. compares sorted files and shows differences 2. selects lines or rows 3. counts characters, words, or lines in a file 4. selects columns (fields) 5. compares and selects differences in two files 6. formats and prints 7. edits data streams 8. sorts and merges multiple files 9. translates and deletes character by character Choose from: comm cut diff grep pr sed sort tr wc
1. comm 2. grep 3. wc 4. cut 5. diff 6. pr 7. sed 8. sort 9. tr
You can use the ____ operator to redirect commands or program error messages from the screen to a file. 1> 2> 3> 4>
2>
By default, pr formats the specified files into single-column pages of ____ lines. 22 33 55 66
66
can be used with cat to combine the contents of two files paste -i > (gt;) -t -u -d -r -c -name
> (gt;)
A high-level language is a computer language that uses English-like expressions. True False
True
Moving and renaming a file are essentially the same operation. True False
True
The Bash shell offers improved features over the older Bourne and Korn shells and is fully backward compatible with the Bourne shell. True False
True
The pipe operator can connect several commands on the same command line. True False
True
UNIX/Linux store data, such as letters, product records, or vendor reports, in flat ASCII files. True False
True
You can complete a project using awk that you cannot complete using a combination of paste, cut, sort, and join. True False
True
You can use the less command with a directory to view its contents one screen at a time, such as less /sbin. True False
True
You can use the vi editor to create script files. True False
True
You should omit spaces when you assign a variable without using single or double quotation marks around its value. True False
True
To append new lines in sed, you must use the ____ command a\ -a \a >a
a\
The ____ command is used to look for patterns in files. awk find pattern search
awk
The ____ statement simplifies the selection of a match when you have a list of choices. if switch case while
case
Logic structures supported by shell scripts include: sequential logic, decision logic, looping logic, and ____________________ logic.
case?
____ gives the owner read, write, and execute permissions. chmod 155 chmod 551 chmod 577 chmod 755
chmod 755
The ____ command locates identical lines within two identically sorted files. diff sed uniq comm
comm
The ____ reads the lines of code that the programmer wrote in the source file and converts them to the appropriate machine-language instructions. compiler linker assembler interpreter
compiler
Logic structures are also called ____ structures. decision sequential control programming
control
The command > accountsfile ____. deletes de file accountsfile is not valid in UNIX/Linux systems displays the contents of the file accountsfile on the screen creates an empty file called accountsfile
creates an empty file called accountsfile
To reference a variable, you use a dollar sign ($) in front of it or enclose it in ____. square brackets ([ ]) curly brackets ({ }) double quotes (“ ”) angle brackets (< >)
curly brackets ({ })
When you assign a value to a variable, you might want to evaluate it by displaying its contents via a(n) ____ operator. definition echo evaluating print
evaluating
By default, each page in the output of pr has a ____-line header, which, by default, contains the current file's name, its last modification date, the current page, and a trailer consisting of blank lines. three four five six
five
Wildcard characters are also known as ____ characters. bogus filler glob search
glob
You use the ____ command to search for a specified pattern in a file, such as a particular word or phrase. find grep sed diff
grep
The UNIX/Linux shell acts as a(n) ____ when reading script files. compiler interpreter assembler linker
interpreter
A sorting ____ is a field position within each line. index key column position
key
The join command is used to associate information in two different files on the basis of a common field or ____ in those files. index link column key
key
To redirect the list of the files in a directory to a file called homedir.list, you enter ____. ls < homedir.list ls > homedir.list homedir.list < ls homedir.list > ls
ls > homedir.list
To move a file, you use the ____ command along with the source file name and destination name. rm rename mv move
mv
combines files side by side paste -i > (gt;) -t -u -d -r -c -name
paste
The ____ redirects the output of one command to the input of another command. output redirection operator (>) input redirection operator (<) pipe operator (|) tilde (~)
pipe operator (|)
You use the ____ character in script files to mark comments. tilde (~) dollar ($) pipe (|) pound (#)
pound (#)
The ____ command prints a listing of environment and configuration variables. printenv printvar printf bash
printenv
The ____ function within the awk command is used to format output. out outln print printf
printf
Character special files are used by input/output devices for communicating one character at a time, providing what is called ____ data. raw binary ASCII block
raw
In UNIX/Linux, text files and binary files are considered to be ____ files. executable document regular dynamic
regular
The ____ option of the uniq command instructs it to generate as output only the lines of the source file that are not duplicated successively. -d -s -o -u
-u
when deleting a directory with rm, this option is used to recursively delete its files and subdirectories paste -i > (gt;) -t -u -d -r -c -name
-r
The cp ____ option creates a symbolic link or name at the destination rather than a physical file. -s -y -l -n
-s
option of the sort command used to indicate that a specific character separates the fields paste -i > (gt;) -t -u -d -r -c -name
-t
When using the printf function, ____ indicates that the output is to appear in decimal digits. %i -i %d -d
%d
The ____ option of the diff command does not compare for blank lines. -b -B -c -C
-B
The ____ option of the diff command ignores blanks that repeat. -b -B -c -C
-b
The ____ option of the diff command shows lines surrounding the line that differs. -d -D -c -C
-c
this option prevents the touch command from creating a file, if it does not already exist paste -i > (gt;) -t -u -d -r -c -name
-c
The ____ option of the paste command is used to specify a different separator as a delimiter. -t -o -d -s
-d
option of the cut command used to indicate that a specific character separates the fields paste -i > (gt;) -t -u -d -r -c -name
-d
option of the cp command that provides a warning before an existing file with the same name is overwritten paste -i > (gt;) -t -u -d -r -c -name
-i
The ____ option of the find command displays files that have been changed within the last n minutes. -min n -cmin n -nmin n -mmin n
-mmin n
The ____ option of the find command displays files that have been changed within the last n days. -cdays n -ctime n -mdays n -mtime n
-mtime n
is an option of the find command paste -i > (gt;) -t -u -d -r -c -name
-name
When you use find, it is useful to note that some UNIX versions require the ____ option after the file name to display the names of files. -display -print -show -names
____ is a full-featured programming language. Sed Awk Emacs Grep
Awk
The ____ shell, when compared to the other shells, has a more powerful programming interface. Bourne Bash C Korn
Bash
____ variables are used to store information about the setup of the operating system, and after they are set up, you typically do not change them. Global Environment Configuration Shell
Configuration
A popular use of pr is to convert lowercase characters to uppercase characters. True False
False
Shell scripts can automatically access variables created and assigned on the command line. True False
False
Shell scripts run more quickly than compiled programs. True False
False
The command rmdir can be used to delete a directory that is not empty. True False
False
When using wc, you cannot specify all three options (-l, -w and -c) in the command line at the same time. True False
False
When you are moving files, using the -o option with the mv command can be a good idea so that you don't unexpectedly overwrite a destination file with the same name. True False
False
When you use cat to combine two files into a third file, the first line of the output contains the first line of the first file followed by the first line of the second file. True False
False
When you use the paste command, by default, the pasted results appear in columns separated by commas. True False
False
You can use the < operator to redirect a command's output from the screen to a file. True False
False
You use the chexec command to indicate that a (shell script) file can be executed. True False
False
You can use the ____________________ command to associate lines in two files on the basis of a common field in both files.
Join?
Bash is a freeware derivative of the Bourne and ____ shells. Korn C csh tsh
Korn
____ operators compare the relationship between two values or arguments. Evaluation Comparison Logical Relational
Relational
____ variables are those you create at the command line or in a shell script. Global Environment Configuration Shell
Shell
