From db187fb65fd2ca3f67d8f1b347e6b15f2c9a85ca Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Sun, 9 Nov 2025 17:51:12 +0000 Subject: [PATCH 1/7] Answers all questions in README for number systems exercises --- number-systems/README.md | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/number-systems/README.md b/number-systems/README.md index 77a3bde94..8852f9348 100644 --- a/number-systems/README.md +++ b/number-systems/README.md @@ -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 How many bits would you need in order to store the numbers between 0 and 3 inclusive? -Answer: +Answer: 2 How many bits would you need in order to store the numbers between 0 and 1000 inclusive? -Answer: +Answer: 10 How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)? -Answer: +Answer: A binary number is a power of two if it has exactly one bit in it. Convert the decimal number 14 to hex. -Answer: +Answer: 0xE Convert the decimal number 386 to hex. -Answer: +Answer: 182 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: Grey 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: Purple If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be? -Answer: +Answer: 170, 0, 255 From 52333450153c543470ccb7c549a76e77b88a7bc8 Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Sun, 9 Nov 2025 18:32:44 +0000 Subject: [PATCH 2/7] Answered ls folder question --- individual-shell-tools/ls/script-01.sh | 2 ++ individual-shell-tools/ls/script-02.sh | 2 ++ individual-shell-tools/ls/script-03.sh | 1 + individual-shell-tools/ls/script-04.sh | 3 +++ 4 files changed, 8 insertions(+) diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh index 241b62f5e..8f93bb79e 100755 --- a/individual-shell-tools/ls/script-01.sh +++ b/individual-shell-tools/ls/script-01.sh @@ -13,3 +13,5 @@ fi # TODO: Write a command to list the files and folders in this directory. # The output should be a list of names including child-directory, script-01.sh, script-02.sh, and more. + +ls \ No newline at end of file diff --git a/individual-shell-tools/ls/script-02.sh b/individual-shell-tools/ls/script-02.sh index d0a5a10f4..f4cdf0f8e 100755 --- a/individual-shell-tools/ls/script-02.sh +++ b/individual-shell-tools/ls/script-02.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command which lists all of the files in the directory named child-directory. # The output should be a list of names: helper-1.txt, helper-2.txt, helper-3.txt. +ls child-directory or cd child-directory && ls + diff --git a/individual-shell-tools/ls/script-03.sh b/individual-shell-tools/ls/script-03.sh index 781216d21..5161171ec 100755 --- a/individual-shell-tools/ls/script-03.sh +++ b/individual-shell-tools/ls/script-03.sh @@ -5,3 +5,4 @@ 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. # 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. +ls -R diff --git a/individual-shell-tools/ls/script-04.sh b/individual-shell-tools/ls/script-04.sh index 72f3817b3..7145953c4 100755 --- a/individual-shell-tools/ls/script-04.sh +++ b/individual-shell-tools/ls/script-04.sh @@ -15,9 +15,12 @@ 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. # The output should be a list of names in this order, one per line: helper-3.txt, helper-1.txt, helper-2.txt. +ls -t child-directory + 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). # The output should be a list of names in this order, one per line: helper-2.txt, helper-1.txt, helper-3.txt. +ls -tr child-directory From 5b56813b96f09fbd469267a83401c1f09b3870ac Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Sun, 9 Nov 2025 19:22:05 +0000 Subject: [PATCH 3/7] Answered all questions for cat --- individual-shell-tools/cat/script-01.sh | 1 + individual-shell-tools/cat/script-02.sh | 1 + individual-shell-tools/cat/script-03.sh | 1 + individual-shell-tools/cat/script-04-stretch.sh | 1 + 4 files changed, 4 insertions(+) diff --git a/individual-shell-tools/cat/script-01.sh b/individual-shell-tools/cat/script-01.sh index c85053e0f..edcc54fb4 100755 --- a/individual-shell-tools/cat/script-01.sh +++ b/individual-shell-tools/cat/script-01.sh @@ -4,3 +4,4 @@ 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. # The output of this command should be "Once upon a time...". +cat ../helper-files/helper-1.txt diff --git a/individual-shell-tools/cat/script-02.sh b/individual-shell-tools/cat/script-02.sh index 01bbd5eab..189d5e0e5 100755 --- a/individual-shell-tools/cat/script-02.sh +++ b/individual-shell-tools/cat/script-02.sh @@ -11,3 +11,4 @@ set -euo pipefail # It looked delicious. # I was tempted to take a bite of it. # But this seemed like a bad idea... +cat ../helper-files/*.* diff --git a/individual-shell-tools/cat/script-03.sh b/individual-shell-tools/cat/script-03.sh index 37573b0c1..dd6b1d8b1 100755 --- a/individual-shell-tools/cat/script-03.sh +++ b/individual-shell-tools/cat/script-03.sh @@ -9,3 +9,4 @@ set -euo pipefail # 1 It looked delicious. # 2 I was tempted to take a bite of it. # 3 But this seemed like a bad idea... +cat -n ../helper-files/helper-3.txt diff --git a/individual-shell-tools/cat/script-04-stretch.sh b/individual-shell-tools/cat/script-04-stretch.sh index 00fe3c48b..bd35f85b7 100755 --- a/individual-shell-tools/cat/script-04-stretch.sh +++ b/individual-shell-tools/cat/script-04-stretch.sh @@ -13,3 +13,4 @@ set -euo pipefail # 3 It looked delicious. # 4 I was tempted to take a bite of it. # 5 But this seemed like a bad idea... +cat ../helper-files/*.* | nl From 201242cf91eb9fd9e5d54ab8026c07ec622736ea Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Sun, 9 Nov 2025 19:43:19 +0000 Subject: [PATCH 4/7] Answered all the questions in wc --- individual-shell-tools/wc/script-01.sh | 1 + individual-shell-tools/wc/script-02.sh | 1 + individual-shell-tools/wc/script-03.sh | 2 ++ 3 files changed, 4 insertions(+) diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh index c9dd6e5df..e71a2da9b 100755 --- a/individual-shell-tools/wc/script-01.sh +++ b/individual-shell-tools/wc/script-01.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output the number of words in the file helper-files/helper-3.txt. # The output should include the number 19. The output should not include the number 92. +wc -w ../helper-files/helper-3.txt | awk '{print $1}' diff --git a/individual-shell-tools/wc/script-02.sh b/individual-shell-tools/wc/script-02.sh index 8feeb1a62..89819fe9b 100755 --- a/individual-shell-tools/wc/script-02.sh +++ b/individual-shell-tools/wc/script-02.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output the number of lines in the file helper-files/helper-3.txt. # The output should include the number 3. The output should not include the number 19. +wc -l ../helper-files/helper-3.txt | awk '{print $1}' diff --git a/individual-shell-tools/wc/script-03.sh b/individual-shell-tools/wc/script-03.sh index 6b2e9d3d1..a921f78d1 100755 --- a/individual-shell-tools/wc/script-03.sh +++ b/individual-shell-tools/wc/script-03.sh @@ -8,3 +8,5 @@ set -euo pipefail # 1 7 39 ../helper-files/helper-2.txt # 3 19 92 ../helper-files/helper-3.txt # 5 30 151 total +wc ../helper-files/*.* + From 72d9a1403b03e238a401e8751197c936321713e6 Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Sun, 9 Nov 2025 20:33:03 +0000 Subject: [PATCH 5/7] Answered all questions for grep --- individual-shell-tools/grep/script-01.sh | 3 +++ individual-shell-tools/grep/script-02.sh | 1 + individual-shell-tools/grep/script-03.sh | 2 ++ individual-shell-tools/grep/script-04.sh | 1 + individual-shell-tools/grep/script-05.sh | 3 +++ individual-shell-tools/grep/script-06.sh | 1 + individual-shell-tools/grep/script-07.sh | 2 ++ 7 files changed, 13 insertions(+) diff --git a/individual-shell-tools/grep/script-01.sh b/individual-shell-tools/grep/script-01.sh index fb05f42f2..efd04658e 100755 --- a/individual-shell-tools/grep/script-01.sh +++ b/individual-shell-tools/grep/script-01.sh @@ -4,3 +4,6 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt said by the Doctor. # The output should contain 6 lines. +grep "^Doctor:" dialogue.txt + + diff --git a/individual-shell-tools/grep/script-02.sh b/individual-shell-tools/grep/script-02.sh index df6f85640..5ba3119d8 100755 --- a/individual-shell-tools/grep/script-02.sh +++ b/individual-shell-tools/grep/script-02.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt that contains the word Doctor (regardless of case). # The output should contain 9 lines. +grep -i "Doctor" dialogue.txt diff --git a/individual-shell-tools/grep/script-03.sh b/individual-shell-tools/grep/script-03.sh index 5383fe578..be2269713 100755 --- a/individual-shell-tools/grep/script-03.sh +++ b/individual-shell-tools/grep/script-03.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command to output the number of lines in dialogue.txt that contain the word Doctor (regardless of case). # The output should be exactly the number 9. +grep -ic "Doctor" dialogue.txt + diff --git a/individual-shell-tools/grep/script-04.sh b/individual-shell-tools/grep/script-04.sh index 80ee04776..2515708d3 100755 --- a/individual-shell-tools/grep/script-04.sh +++ b/individual-shell-tools/grep/script-04.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output every line in dialogue.txt that does not contain the word "Hello" (regardless of case). # The output should contain 10 lines. +grep -vi "Hello" dialogue.txt diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh index 1eb538185..61da70ab3 100755 --- a/individual-shell-tools/grep/script-05.sh +++ b/individual-shell-tools/grep/script-05.sh @@ -4,3 +4,6 @@ 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. # The output should contain two pairs of two lines of text (with a separator between them). +grep -i -B 1 "cure" dialogue.txt + + diff --git a/individual-shell-tools/grep/script-06.sh b/individual-shell-tools/grep/script-06.sh index 5670e3b6c..ba394de04 100755 --- a/individual-shell-tools/grep/script-06.sh +++ b/individual-shell-tools/grep/script-06.sh @@ -4,3 +4,4 @@ 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. # The output should contain two filenames. +grep -l "Doctor:" *.txt diff --git a/individual-shell-tools/grep/script-07.sh b/individual-shell-tools/grep/script-07.sh index 9670ebad9..bcb03cf3a 100755 --- a/individual-shell-tools/grep/script-07.sh +++ b/individual-shell-tools/grep/script-07.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command to output, for each `.txt` file in this directory, how many lines of dialogue the Doctor has. # The output should show that dialogue.txt contains 6 lines, dialogue-2.txt contains 2, and dialogue-3.txt contains 0. +grep -c "^Doctor:" *.txt + From 7eae892cecbf2146b5037c795529a6f8417c6634 Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Mon, 10 Nov 2025 17:41:58 +0000 Subject: [PATCH 6/7] answered all question for sed --- individual-shell-tools/sed/script-01.sh | 1 + individual-shell-tools/sed/script-02.sh | 1 + individual-shell-tools/sed/script-03.sh | 4 +++- individual-shell-tools/sed/script-04.sh | 1 + individual-shell-tools/sed/script-05.sh | 2 ++ individual-shell-tools/sed/script-06.sh | 1 + 6 files changed, 9 insertions(+), 1 deletion(-) diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh index 3eba6fa4d..c63cbcf86 100755 --- a/individual-shell-tools/sed/script-01.sh +++ b/individual-shell-tools/sed/script-01.sh @@ -5,3 +5,4 @@ set -euo pipefail # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`. # The output should contain 11 lines. # The first line of the output should be: "ThIs Is a sample fIle for experImentIng with sed.". +sed 's/i/I/g' ./input.txt diff --git a/individual-shell-tools/sed/script-02.sh b/individual-shell-tools/sed/script-02.sh index abdd64d06..f20730153 100755 --- a/individual-shell-tools/sed/script-02.sh +++ b/individual-shell-tools/sed/script-02.sh @@ -5,3 +5,4 @@ set -euo pipefail # TODO: Write a command to output input.txt with numbers removed. # The output should contain 11 lines. # Line 6 of the output should be " Alisha". +sed 's/[0-9]//g' ./input.txt diff --git a/individual-shell-tools/sed/script-03.sh b/individual-shell-tools/sed/script-03.sh index dd284a296..24d76c281 100755 --- a/individual-shell-tools/sed/script-03.sh +++ b/individual-shell-tools/sed/script-03.sh @@ -3,4 +3,6 @@ set -euo pipefail # TODO: Write a command to output input.txt removing any line which contains a number. -# The output should contain 6 lines. +# The output should contain 6 lines. +sed '/[0-9]/d' ./input.txt + diff --git a/individual-shell-tools/sed/script-04.sh b/individual-shell-tools/sed/script-04.sh index 0052ac6c4..481313eab 100755 --- a/individual-shell-tools/sed/script-04.sh +++ b/individual-shell-tools/sed/script-04.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output input.txt replacing every occurrence of the string "We'll" with "We will". # The output should contain 11 lines. +sed "s/We'll/We will/g" ./input.txt diff --git a/individual-shell-tools/sed/script-05.sh b/individual-shell-tools/sed/script-05.sh index 2dcc91a0c..9f0062648 100755 --- a/individual-shell-tools/sed/script-05.sh +++ b/individual-shell-tools/sed/script-05.sh @@ -6,3 +6,5 @@ set -euo pipefail # 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. +sed -E 's/^([0-9]+) (.*)/\2 \1/' ./input.txt + diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh index 0b9390170..605f6fa85 100755 --- a/individual-shell-tools/sed/script-06.sh +++ b/individual-shell-tools/sed/script-06.sh @@ -8,3 +8,4 @@ set -euo pipefail # The output should contain 11 lines. # Line 3 should be "It contains many lines, and there are some things you may want to do with each of them.". # Line 11 should be "We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.". +sed 's/, */, /g' ./input.txt From a056eb92ae25e92479cab29aee5d7bb7185b662c Mon Sep 17 00:00:00 2001 From: "Tewodros T. Bekere" Date: Mon, 10 Nov 2025 17:42:44 +0000 Subject: [PATCH 7/7] answered all questions for awk --- individual-shell-tools/awk/script-01.sh | 1 + individual-shell-tools/awk/script-02.sh | 1 + individual-shell-tools/awk/script-03.sh | 1 + individual-shell-tools/awk/script-04.sh | 2 ++ individual-shell-tools/awk/script-05.sh | 2 ++ individual-shell-tools/awk/script-06-stretch.sh | 2 ++ individual-shell-tools/awk/script-07-stretch.sh | 1 + 7 files changed, 10 insertions(+) diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh index 8db4390af..90e2397d6 100755 --- a/individual-shell-tools/awk/script-01.sh +++ b/individual-shell-tools/awk/script-01.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player in `scores-table.txt`. # Your output should contain 6 lines, each with just one word on it. +awk '{print $1}' scores-table.txt diff --git a/individual-shell-tools/awk/script-02.sh b/individual-shell-tools/awk/script-02.sh index 5956be9bd..da34660ab 100755 --- a/individual-shell-tools/awk/script-02.sh +++ b/individual-shell-tools/awk/script-02.sh @@ -4,3 +4,4 @@ set -euo pipefail # TODO: Write a command to output the names of each player, as well as their city. # Your output should contain 6 lines, each with two words on it, separated by a space. +awk '{print $1, $2}' scores-table.txt diff --git a/individual-shell-tools/awk/script-03.sh b/individual-shell-tools/awk/script-03.sh index af7c6e8b9..55c51c48e 100755 --- a/individual-shell-tools/awk/script-03.sh +++ b/individual-shell-tools/awk/script-03.sh @@ -5,3 +5,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player along with the score from their first attempt. # Your output should contain 6 lines, each with one word and one number on it. # The first line should be "Ahmed 1". +awk '{print $1, $3}' scores-table.txt diff --git a/individual-shell-tools/awk/script-04.sh b/individual-shell-tools/awk/script-04.sh index bf15703c7..764913a82 100755 --- a/individual-shell-tools/awk/script-04.sh +++ b/individual-shell-tools/awk/script-04.sh @@ -5,3 +5,5 @@ 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. # Your output should contain 3 lines, each with one word and one number on it. # The first line should be "Ahmed 4". +awk '$2 == "London" {print $1, $5}' scores-table.txt + diff --git a/individual-shell-tools/awk/script-05.sh b/individual-shell-tools/awk/script-05.sh index d1680cb02..0fa0118e4 100755 --- a/individual-shell-tools/awk/script-05.sh +++ b/individual-shell-tools/awk/script-05.sh @@ -5,3 +5,5 @@ 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. # Your output should contain 6 lines, each with one word and one number on it. # The first line should be "Ahmed 3". +awk '{print $1, NF-2}' scores-table.txt + diff --git a/individual-shell-tools/awk/script-06-stretch.sh b/individual-shell-tools/awk/script-06-stretch.sh index 0201e6378..ed6ae90bf 100755 --- a/individual-shell-tools/awk/script-06-stretch.sh +++ b/individual-shell-tools/awk/script-06-stretch.sh @@ -6,3 +6,5 @@ set -euo pipefail # TODO: Write a command to output the total of adding together all players' first scores. # Your output should be exactly the number 54. +awk '{sum += $3} END {print sum}' scores-table.txt + diff --git a/individual-shell-tools/awk/script-07-stretch.sh b/individual-shell-tools/awk/script-07-stretch.sh index 3f7155880..79ceb2fdb 100755 --- a/individual-shell-tools/awk/script-07-stretch.sh +++ b/individual-shell-tools/awk/script-07-stretch.sh @@ -7,3 +7,4 @@ set -euo pipefail # TODO: Write a command to output just the names of each player along with the total of adding all of that player's scores. # Your output should contain 6 lines, each with one word and one number on it. # The first line should be "Ahmed 15". The second line should be "Basia 37" +awk '{sum=0; for(i=3;i<=NF;i++) sum+= $i; print $1, sum}' scores-table.txt