Sem I (Prak Grund Infor) - N4

Question 1

What Bash Kommand “grep” do?

Answer 1

Search text or search for patterns within files

Question 2

Bash Kommand to start with

Answer 2

Find all lines in a text file that start with the word "hello"
grep "^hello" file.txt

Quickly replace a string in a previous command and execute it
^old_string^new_string

Question 3

Das Bash-Linux-Kommando die normalerweise mit dem find-Befehl verwendet, um eine Aktion auf Dateien auszuführen, die durch das find-Kommando gefunden wurden.

Answer 3

-exec

find /pfad/zum/verzeichnis -name "dateiname" -exec rm {} \;
Die {} wird durch den Dateinamen ersetzt, und \; gibt das Ende des -exec-Befehls an.

Question 4

Was macht folgendes regular expression “?”

Answer 4

Matching zero or one occurrence

Question 5

Was macht folgendes Bash Kommand “echo $PPID”

Answer 5

PID des Parent

Question 6

Was macht folgendes Linux Bash Kommand: echo -e

Answer 6

Wird verwendet, um Text auszugeben und spezielle Escape-Sequenzen innerhalb des Textes zu interpretieren. ZB. \n und \t

echo -e "Zeile 1\nZeile 2"
Zeile 1
Zeile 2

Question 7

Что такое Gleitkommazahlen

Answer 7

Это числа с плавающей запятой. Числа с плавающей запятой - это вид числового представления, используемого в информатике для представления широкого диапазона реальных чисел. Например: 1,2345 * 10^2

Question 8

How to much whitespace in Linux Bash Regular expression?

Answer 8

[[:space:]]

Question 9

Linux Bash Regular Expression to much alphanumeric Characters

Answer 9

[[:alnum:]]

Question 10

What zcat command in Linux Bash do?

Answer 10

Used to view the contents of compressed files without actually decompressing them.

Question 11

How to view the contents of compressed files without actually decompressing them in Linux Bash?

Answer 11

zcat

Question 12

What following Bash Linux command do: "cat countries.txt <(echo ---------) countries_1.txt"

Answer 12

The string “———” is inserted (as if it were the contents of a file).

USA
Canada
Mexico
---------
France
Germany
Italy

Question 13

What linux bash command cut do?

Answer 13

Used to extract sections from each line of input, typically from files or from standard input.

Extract by Byte Position
cut -b 1-4 filename

Question 14

How to extract sections from each line of input, typically from files or from standard input?

Answer 14

cut

Question 15

What “cut -b” command do?

Answer 15

Extract sections from each line of input
-b (bytes): Select only these bytes from each line.

cut -b 1-4 filename
This command extracts the first 4 bytes from each line of the file filename.

Question 16

What “cut -c” command do?

Answer 16

Extract sections from each line of input
-c (characters): Select only these characters from each line.

cut -c 1-4 filename
This command extracts the first 4 characters from each line of the file filename.

Question 17

What “cut -d” command do?

Answer 17

Extract sections from each line of input
-d (delimiter): Specify a delimiter that separates fields (default is tab).

cut -d ':' -f 1,3 filename
This command uses the colon : as a delimiter and extracts the first and third fields from each line of the file filename.

Question 18

What “cut -f” command do?

Answer 18

Extract sections from each line of input
-f (fields): Select only these fields, separated by the delimiter.

John,Doe,30,Engineer
Jane,Smith,25,Doctor
Jim,Brown,22,Teacher

cut -d ',' -f 1,3 data.txt
-d ',': Sets the delimiter to a comma.
-f 1,3: Specifies that we want to extract the 1st and 3rd fields.

Output:
John,30
Jane,25
Jim,22

Question 19

How to sort file for Example alphabetical using Linux Bash?

Answer 19

sort filename

Question 20

What “sort filename” command in Linux Bash do?

Answer 20

This command sorts the lines of the file filename in alphabetical order.

Question 21

How to sort file in reverse order using Linux Bash?

Answer 21

sort -r filename

Question 22

How to sort file Numerically using Linux Bash?

Answer 22

sort -n filename

Question 23

How to sort file by a Specific Field using Linux Bash?

Answer 23

sort -k 2 filename

Question 24

How to sort file by Specify a Field Separator using Linux Bash?

Answer 24

sort -t ',' -k 2 filename

Question 25

How to sort file ignoring CASE using Linux Bash?

Answer 25

sort -f filename

Question 26

How to sort file Human-Readable Numeric Format using Linux Bash?

Answer 26

sort -h filename

This command sorts lines that contain human-readable numbers (e.g., 1K, 2M, 3G).

Question 27

How to sort Remove Duplicates using Linux Bash?

Answer 27

sort -u filename

Question 28

How to sort numerically in reverse order using Linux Bash?

Answer 28

sort -nr filename

Question 29

What does the Linux Bash command join do?

Answer 29

Used to combine lines from two files based on a common field. Similar to a database join.

Question 30

How to join files using Linux Bash command?

Answer 30

join file1 file2

Question 30

How to join files based on the common first field using Linux Bash command

Answer 30

join file1.txt file2.txt
file1.txt
1 Alice
2 Bob
3 Charlie

file2.txt
1 2000
2 1500
3 3000

Output:
1 Alice 2000
2 Bob 1500
3 Charlie 3000

Question 31

How to join files with delimiter using Linux Bash command

Answer 31

join -t ',' file3.txt file4.txt

Question 32

How to join file5.txt on the second field and file6.txt on the first field using Linux Bash command

Answer 32

join -1 2 -2 1 file5.txt file6.txt

Question 33

How to join and control which fields to include in the output using Linux Bash command

Answer 33

join -o 1.2,2.2 file5.txt file6.txt

Question 34

What does the Linux Bash command tr do?

Answer 34

Used to translate or delete characters from the input provided.

Question 35

How to translate characters using Bash Linux.
For example: all lowercase letters to uppercase in the string

Answer 35

echo "hello world" | tr 'a-z' 'A-Z'
This command translates all lowercase letters to uppercase in the string "hello world".

===> HELLO WORLD

Question 36

How to delete characters using “tr” and Bash Linux

Answer 36

The -d option deletes specified characters from the input.

echo "hello world" | tr -d 'l'
This command deletes all occurrences of the character 'l' from the string "hello world".
===> heo word

Question 37

How to replaces sequences of repeated characters with a single instance using Bash Linux

Answer 37

echo "hello     world" | tr -s ' '
This command replaces sequences of spaces with a single space in the string "hello world".
hello world

Question 38

How to combine translation and squeezing of characters using Bash Linux.
For example do this: translates spaces to newlines and then squeezes repeated newlines into a single newline.

Answer 38

echo "hello     world" | tr ' ' '\n' | tr -s '\n'
This command translates spaces to newlines and then squeezes repeated newlines into a single newline.
hello
world

Question 39

How to Translate and Delete Characters using Bash Linux
For Example: “hello123 world456” from lower to upper and del all characters exept digits

Answer 39

echo "hello123 world456" | tr 'a-z' 'A-Z' | tr -d '0-9'
HELLO WORLD

Question 40

How keeps only the digits from the string using Bash Linux

Answer 40

echo "hello123 world456" | tr -cd '0-9'
This command keeps only the digits from the string "hello123 world456"
===> 123456

Question 41

What does the Linux Bash command tee do?

Answer 41

Used to read from standard input and write to both standard output and one or more files simultaneously.

Question 42

Runs command, then writes its output to both the terminal and file.txt using Bash Linux.

Answer 42

command | tee file.txt

Question 43

Capturing Output to a File While Displaying It using Bash Linux.

Answer 43

echo "Hello, World!" | tee output.txt

Question 44

Append to a file instead of overwriting it using Bash Linux.

Answer 44

echo "Another line" | tee -a output.txt

Question 45

Writing to Multiple Files using Bash Linux.

Answer 45

echo "Hello, again!" | tee file1.txt file2.txt

Question 46

First Show Lists files in long format, writes the output to ls_output.txt, and then filters the list to show only .txt files. using Bash Linux.

Answer 46

ls -l | tee ls_output.txt | grep "\.txt"

Question 47

What does the Linux Bash command sed do?

Answer 47

Powerful stream editor used for performing basic text transformations on an input stream (a file or input from a pipeline). Searching, replacing, inserting, and deleting text.

Question 48

Replaces the first occurrence of “old” with “new” in each line of the file with sed using Bash Linux.

Answer 48

sed 's/old/new/' file

Question 49

Replaces all occurrences of “old” with “new” in each line of the file with sed using Bash Linux.

Answer 49

sed 's/old/new/g' file

Substitute with Case Insensitivity
sed 's/old/new/I' file