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1 change: 1 addition & 0 deletions individual-shell-tools/awk/script-01.sh
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set -euo pipefail

# TODO: Write a command to output just the names of each player in `scores-table.txt`.
awk '{print $1}' scores-table.txt
# Your output should contain 6 lines, each with just one word on it.
1 change: 1 addition & 0 deletions individual-shell-tools/awk/script-02.sh
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set -euo pipefail

# TODO: Write a command to output the names of each player, as well as their city.
awk '{print $1,$2}' scores-table.txt
# Your output should contain 6 lines, each with two words on it, separated by a space.
1 change: 1 addition & 0 deletions individual-shell-tools/awk/script-03.sh
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set -euo pipefail

# TODO: Write a command to output just the names of each player along with the score from their first attempt.
awk '{print $1,$3}' scores-table.txt
# Your output should contain 6 lines, each with one word and one number on it.
# The first line should be "Ahmed 1".
1 change: 1 addition & 0 deletions individual-shell-tools/awk/script-04.sh
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set -euo pipefail

# TODO: Write a command to output just the names of each player in London along with the score from their last attempt.
awk '$2 =="London" {print $1,$5}' scores-table.txt

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Will this still work if the player makes more than a few attempts?

# Your output should contain 3 lines, each with one word and one number on it.
# The first line should be "Ahmed 4".
1 change: 1 addition & 0 deletions individual-shell-tools/awk/script-05.sh
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set -euo pipefail

# TODO: Write a command to output just the names of each player along with the number of times they've played the game.
awk '{print $1,NF-2}' scores-table.txt
# Your output should contain 6 lines, each with one word and one number on it.
# The first line should be "Ahmed 3".
2 changes: 2 additions & 0 deletions individual-shell-tools/cat/script-01.sh
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set -euo pipefail

# TODO: Write a command to output the contents of the helper-1.txt file inside the helper-files directory to the terminal.
cd helper-files
cat helper-1.txt
# The output of this command should be "Once upon a time...".
2 changes: 2 additions & 0 deletions individual-shell-tools/cat/script-02.sh
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Expand Up @@ -4,6 +4,8 @@ set -euo pipefail

# TODO: Write a command to output the contents of all of the files inside the helper-files directory to the terminal.
# Make sure you are only calling `cat` once.
cd helper-files
cat *
#
# The output of this command should be:
# Once upon a time...
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3 changes: 2 additions & 1 deletion individual-shell-tools/cat/script-03.sh
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Expand Up @@ -4,7 +4,8 @@ set -euo pipefail

# TODO: Write a command to output the contents of the file `helper-3.txt` inside the helper-files directory to the terminal.
# This time, we also want to see the line numbers in the output.
#
cd helper-files
cat -n helper-3.txt
# The output of this command should be something like:
# 1 It looked delicious.
# 2 I was tempted to take a bite of it.
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2 changes: 2 additions & 0 deletions individual-shell-tools/cat/script-04-stretch.sh
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Expand Up @@ -6,6 +6,8 @@ set -euo pipefail

# TODO: Write a command to output the contents of all of the files in the helper-files directory to the terminal.
# We also want to see the line numbers in the output, but we want line numbers not to reset at the start of each file.
cd helper-files
cat helper-1.txt helper-2.txt helper-3.txt | cat -n

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Do you know how to make cat output and number multiple files in a single command?

#
# The output of this command should be something like:
# 1 Once upon a time...
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3 changes: 3 additions & 0 deletions individual-shell-tools/grep/script-01.sh
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set -euo pipefail

# TODO: Write a command to output every line in dialogue.txt said by the Doctor.
cd
grep "^Doctor:" dialouge.txt

# The output should contain 6 lines.
1 change: 1 addition & 0 deletions individual-shell-tools/grep/script-02.sh
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set -euo pipefail

# TODO: Write a command to output every line in dialogue.txt that contains the word Doctor (regardless of case).
grep -i "Doctor" dialogue.txt
# The output should contain 9 lines.
1 change: 1 addition & 0 deletions individual-shell-tools/grep/script-03.sh
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set -euo pipefail

# TODO: Write a command to output the number of lines in dialogue.txt that contain the word Doctor (regardless of case).
grep -i "Doctor" dialogue.txt | wc -l

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Can you complete this task only using grep in a single command?

# The output should be exactly the number 9.
1 change: 1 addition & 0 deletions individual-shell-tools/grep/script-04.sh
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set -euo pipefail

# TODO: Write a command to output every line in dialogue.txt that does not contain the word "Hello" (regardless of case).
grep -v "Hello" dialouge.txt

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The task is also asking about case insensitivity here - can you update your solution for that?

# The output should contain 10 lines.
1 change: 1 addition & 0 deletions individual-shell-tools/grep/script-05.sh
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set -euo pipefail

# TODO: Write a command to output every line in dialogue.txt that contains the string "cure", as well as the line before that line.
grep -B 1 "cure" dialogue.txt
# The output should contain two pairs of two lines of text (with a separator between them).
1 change: 1 addition & 0 deletions individual-shell-tools/grep/script-06.sh
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set -euo pipefail

# TODO: Write a command to output the name of every `.txt` file in this directory which contains a line of dialogue said by the Doctor.
grep "^Doctor" *.txt

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Can you build a single grep command that only shows the filename in the output?

# The output should contain two filenames.
1 change: 1 addition & 0 deletions individual-shell-tools/grep/script-07.sh
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set -euo pipefail

# TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has.
grep -Hc "^Doctor" *.txt
# The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0.
1 change: 1 addition & 0 deletions individual-shell-tools/ls/script-01.sh
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Expand Up @@ -12,4 +12,5 @@ if [[ "${script_dir}" != "$(pwd)" ]]; then
fi

# TODO: Write a command to list the files and folders in this directory.
ls
# The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more.
2 changes: 2 additions & 0 deletions individual-shell-tools/ls/script-02.sh
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set -euo pipefail

# TODO: Write a command which lists all of the files in the directory named child-directory.
cd child-directory
ls
# The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt.
1 change: 1 addition & 0 deletions individual-shell-tools/ls/script-03.sh
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set -euo pipefail

# TODO: Write a command which _recursively_ lists all of the files and folders in this directory _and_ all of the files inside those folders.
ls -R
# The output should be a list of names including: child-directory, script-01.sh, helper-1.txt (and more).
# The formatting of the output doesn't matter.
4 changes: 4 additions & 0 deletions individual-shell-tools/ls/script-04.sh
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Expand Up @@ -14,10 +14,14 @@ touch "${script_dir}/child-directory/helper-3.txt"
echo "First exercise (sorted newest to oldest):"

# TODO: Write a command which lists the files in the child-directory directory, one per line, sorted so that the most recently modified file is first.
cd child-directory
ls -1t
# The output should be a list of names in this order, one per line: helper-3.txt, helper-1.txt, helper-2.txt.


echo "Second exercise (sorted oldest to newest):"

# TODO: Write a command which does the same as above, but sorted in the opposite order (oldest first).
cd child-directory
ls -1t | tail -r

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On my system tail -r does not seem to be a valid command. Can you complete this only using a single ls command?

# The output should be a list of names in this order, one per line: helper-2.txt, helper-1.txt, helper-3.txt.
1 change: 1 addition & 0 deletions individual-shell-tools/sed/script-01.sh
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set -euo pipefail

# TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`.
sed 's/i/I/g' input.txt
# The output should contain 11 lines.
# The first line of the output should be: "ThIs Is a sample fIle for experImentIng with sed.".
1 change: 1 addition & 0 deletions individual-shell-tools/sed/script-02.sh
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set -euo pipefail

# TODO: Write a command to output input.txt with numbers removed.
sed 's/[0-9]//g' input.txt
# The output should contain 11 lines.
# Line 6 of the output should be " Alisha".
1 change: 1 addition & 0 deletions individual-shell-tools/sed/script-03.sh
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set -euo pipefail

# TODO: Write a command to output input.txt removing any line which contains a number.
sed '/^[0-9] [[:space]]/d' input.txt

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Is it necessary for your regexp to include the [[:space]] test?

# The output should contain 6 lines.
1 change: 1 addition & 0 deletions individual-shell-tools/sed/script-04.sh
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set -euo pipefail

# TODO: Write a command to output input.txt replacing every occurrence of the string "We'll" with "We will".
sed "s/We'll/We will/g" input.txt
# The output should contain 11 lines.
2 changes: 2 additions & 0 deletions individual-shell-tools/sed/script-05.sh
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set -euo pipefail


# TODO: Write a command to output input.txt with one change:
sed 's/^\([0-9][0-9]*\) \(.*\)/\2 \1/' input.txt

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Do you need two number groups in your regexp here?

# If a line starts with a number and a space, make the line instead end with a space and the number.
# So line 6 which currently reads "37 Alisha" should instead read "Alisha 37".
# The output should contain 11 lines.
1 change: 1 addition & 0 deletions individual-shell-tools/sed/script-06.sh
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set -euo pipefail

# TODO: Write a command to output input.txt with one fix:
sed 's/,\([^[:space:]]\)/, \1/g' input.txt
# If a comma in input.txt is not followed by a space, add a space after.
# If there is already a space after a comma, do not add an additional space.
# The output should contain 11 lines.
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2 changes: 2 additions & 0 deletions individual-shell-tools/wc/script-01.sh
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set -euo pipefail

# TODO: Write a command to output the number of words in the file helper-files/helper-3.txt.
cd helper-files
wc -w helper-3.txt
# The output should include the number 19. The output should not include the number 92.
2 changes: 2 additions & 0 deletions individual-shell-tools/wc/script-02.sh
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set -euo pipefail

# TODO: Write a command to output the number of lines in the file helper-files/helper-3.txt.
cd helper-files
wc -l helper-3.txt
# The output should include the number 3. The output should not include the number 19.
2 changes: 2 additions & 0 deletions individual-shell-tools/wc/script-03.sh
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set -euo pipefail

# TODO: Write a command to output the number of lines, words, and characters in all of the files inside the helper-files directory.
cd helper-files
wc *
# The output should be something like:
# 1 4 20 ../helper-files/helper-1.txt
# 1 7 39 ../helper-files/helper-2.txt
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40 changes: 20 additions & 20 deletions number-systems/README.md

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Hello! Please ensure this PR only contains files for the shell tools exercises.

Please create another PR for the number systems exercise. Creating a separate branch for this will make things easier :)

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Expand Up @@ -5,61 +5,61 @@ Do not convert any binary numbers to decimal when solving a question unless the
The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point.

Convert the decimal number 14 to binary.
Answer:
Answer:1110

Convert the binary number 101101 to decimal:
Answer:
Answer:45

Which is larger: 1000 or 0111?
Answer:
Answer:1000

Which is larger: 00100 or 01011?
Answer:
Answer:01011

What is 10101 + 01010?
Answer:
Answer:11111

What is 10001 + 10001?
Answer:
Answer:100010

What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
Answer:
Answer:15

How many bits would you need in order to store the numbers between 0 and 255 inclusive?
Answer:
Answer:8 bits

How many bits would you need in order to store the numbers between 0 and 3 inclusive?
Answer:
Answer:2bits

How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
Answer:
Answer:10 bits

How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
Answer:
Answer: please explain for me this . Thank you.

Convert the decimal number 14 to hex.
Answer:
Answer:E

Convert the decimal number 386 to hex.
Answer:
Answer:0x182

Convert the hex number 386 to decimal.
Answer:
Answer:902

Convert the hex number B to decimal.
Answer:
Answer:11

If reading the byte 0x21 as a number, what decimal number would it mean?
Answer:
Answer:33

If reading the byte 0x21 as an ASCII character, what character would it mean?
Answer:
Answer: !

If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
Answer:
Answer:gray

If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
Answer:
Answer: No idea . Please help me on this

If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
Answer:
Answer:17, 0, 255