101 exam - terms

Question 1

Other shells

Answer 1

Bash (Boutne again shell)

Dash (Debian Almquist shell, smaller without comman-line editing or command history, faster script execution)

KornShell (compatible with bash, supports advanced programming features)

tcsh (TENEX C shell - upgraded version of C shell, incorporates elements from the C languages into shell scripts)

Z shell (incorporates features from bash, tcsh, KornShell, adv. prog. features, and many others)

Question 2

Metacharacter $

Answer 2

Indicates a variable, with echo command it tries to retrieve the value and display it.

Question 3

Shell quoting

Answer 3

Shell quoting allows you to use metacharacters as regular characters. \ for single metacharacter or ‘ and “ for multiple metacharacters

Question 4

How to tell it’s internal (to the sell) or external command

Answer 4

type -command-
ex:
$ type pwd
pwd is a shell builtin

$ type uname
uname is /usr/bin/uname

Question 5

Environment variables

Answer 5

Environment variables track specific system information, such as the name of the user
logged into the shell, the default home directory for the user, the search path the shell uses to find executable programs, and so on.

Question 6

Executing a program outside the PATH directories

Answer 6

provide the absolute path
ex:
$ /home/Christine/Hello.sh
Hello World

Question 7

which utility

Answer 7

It searches through the PATH directories to
find the program. If it locates the program, it displays its absolute directory reference.
$ which Hello.sh
/usr/bin/which: no Hello.sh in (/usr/local/bin:/usr/bin:
/usr/local/sbin:/usr/sbin:/home/Christine/.local/bin:/home/Christine/bin)

Question 8

changing the environment variable

Answer 8

enter the variable’s name, followed by an equal sign (=), and then type the new value (this setting will not survive entering into a subshell)
ex. of changing PS1 (shell promt):
$ PS1=”My new prompt: “
My new prompt:

Question 9

To preserve an environment variable’s setting

Answer 9

export -variable name-

Question 10

Using the grep command and a digit character class

Answer 10

grep [[:digit:]] random.txt

Question 11

Matches any uppercase alphabetic characters, and is equal to using the [A-Z] bracket expression

Answer 11

[:upper:]

Question 12

Redirect STDIN from specified file into command.

Question 13

Redirect STDOUT and STDERR to specified file. If file exists, overwrite it. If it does not exist, create it.

Answer 13

&>

Question 14

Redirect STDIN from specified file into command and redirect STDOUT to specified file.

Answer 14

<>

Question 15

Redirect STDOUT to specified file. If file exists, overwrite it. If it does not exist, create it.

Answer 15

>

Question 16

Redirect STDOUT to specified file. If file exists, append to it. If it does not exist, create it.

Answer 16

> >

Question 17

Redirect STDERR to specified file. If file exists, overwrite it. If it does not exist, create it.

Answer 17

2>

Question 18

Redirect STDERR to specified file. If file exists, append to it. If it does not exist, create it.

Answer 18

2»

Question 19

Redirect STDOUT and STDERR to specified file. If file exists, append to it. If it does not exist, create it.

Answer 19

&»

Question 20

Matches any alphanumeric characters (any case), and is equal to using the [0-9A-Za-z] bracket expression

Answer 20

[:alnum:]

Question 21

Matches any alphabetic characters (any case), and is equal to using the [A-Za-z] bracket expression

Answer 21

[:alpha:]

Question 22

Matches any blank characters, such as tab and space

Answer 22

[:blank:]

Question 23

Matches any numeric characters, and is equal to using the [0-9] bracket expression

Answer 23

[:digit:]

Question 24

Matches any lowercase alphabetic characters, and is equal to using the [a-z] bracket expression

Answer 24

[:lower:]

Question 25

Matches punctuation characters, such as !, #, $, and @

Answer 25

[:punct:]

Question 26

Matches space characters, such as tab, form feed, and space

Answer 26

[:space:]