diff --git a/individual-shell-tools/awk/script-01.sh b/individual-shell-tools/awk/script-01.sh index 8db4390a..d20122c0 100755 --- a/individual-shell-tools/awk/script-01.sh +++ b/individual-shell-tools/awk/script-01.sh @@ -4,3 +4,7 @@ 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. + +# answer: + +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 5956be9b..a29bbbf1 100755 --- a/individual-shell-tools/awk/script-02.sh +++ b/individual-shell-tools/awk/script-02.sh @@ -4,3 +4,5 @@ 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 af7c6e8b..7934245e 100755 --- a/individual-shell-tools/awk/script-03.sh +++ b/individual-shell-tools/awk/script-03.sh @@ -5,3 +5,5 @@ 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 bf15703c..66d2a71f 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 , $NF}' scores-table.txt \ No newline at end of file diff --git a/individual-shell-tools/awk/script-05.sh b/individual-shell-tools/awk/script-05.sh index d1680cb0..b998bcb6 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 \ No newline at end of file diff --git a/individual-shell-tools/cat/script-01.sh b/individual-shell-tools/cat/script-01.sh index c85053e0..1b86b264 100755 --- a/individual-shell-tools/cat/script-01.sh +++ b/individual-shell-tools/cat/script-01.sh @@ -4,3 +4,6 @@ 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...". +cd .. +cd helper-files +cat helper-1.txt \ No newline at end of file diff --git a/individual-shell-tools/cat/script-02.sh b/individual-shell-tools/cat/script-02.sh index 01bbd5ea..220a0584 100755 --- a/individual-shell-tools/cat/script-02.sh +++ b/individual-shell-tools/cat/script-02.sh @@ -1,6 +1,9 @@ #!/bin/bash set -euo pipefail +cd .. +cd helper-files +cat helper-1.txt helper-2.txt helper-3.txt # 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. diff --git a/individual-shell-tools/cat/script-03.sh b/individual-shell-tools/cat/script-03.sh index 37573b0c..24826db7 100755 --- a/individual-shell-tools/cat/script-03.sh +++ b/individual-shell-tools/cat/script-03.sh @@ -2,6 +2,9 @@ set -euo pipefail +cd .. +cd helper-files +cat -n helper-3.txt # 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. # diff --git a/individual-shell-tools/cat/script-04-stretch.sh b/individual-shell-tools/cat/script-04-stretch.sh index 00fe3c48..4483db07 100755 --- a/individual-shell-tools/cat/script-04-stretch.sh +++ b/individual-shell-tools/cat/script-04-stretch.sh @@ -1,6 +1,10 @@ #!/bin/bash set -euo pipefail +cd .. +cd helper-files + +cat helper-1.txt helper-2.txt helper-3.txt | cat -n # NOTE: This is a stretch exercise - it is optional. diff --git a/individual-shell-tools/grep/script-01.sh b/individual-shell-tools/grep/script-01.sh index fb05f42f..ee1d06d6 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 -i "^Doctor" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-02.sh b/individual-shell-tools/grep/script-02.sh index df6f8564..0a5db33b 100755 --- a/individual-shell-tools/grep/script-02.sh +++ b/individual-shell-tools/grep/script-02.sh @@ -4,3 +4,5 @@ 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 \ No newline at end of file diff --git a/individual-shell-tools/grep/script-03.sh b/individual-shell-tools/grep/script-03.sh index 5383fe57..01ffe3c7 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 -c -i "Doctor" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-04.sh b/individual-shell-tools/grep/script-04.sh index 80ee0477..da0bdd57 100755 --- a/individual-shell-tools/grep/script-04.sh +++ b/individual-shell-tools/grep/script-04.sh @@ -4,3 +4,5 @@ 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 -v -i "Hello" dialogue.txt \ No newline at end of file diff --git a/individual-shell-tools/grep/script-05.sh b/individual-shell-tools/grep/script-05.sh index 1eb53818..b3460107 100755 --- a/individual-shell-tools/grep/script-05.sh +++ b/individual-shell-tools/grep/script-05.sh @@ -1,6 +1,7 @@ #!/bin/bash set -euo pipefail +grep -B 1 "cure" dialogue.txt # 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). diff --git a/individual-shell-tools/grep/script-06.sh b/individual-shell-tools/grep/script-06.sh index 5670e3b6..c34aefd1 100755 --- a/individual-shell-tools/grep/script-06.sh +++ b/individual-shell-tools/grep/script-06.sh @@ -2,5 +2,6 @@ set -euo pipefail +grep -i -l "^Doctor" *.txt # 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. diff --git a/individual-shell-tools/grep/script-07.sh b/individual-shell-tools/grep/script-07.sh index 9670ebad..decc289d 100755 --- a/individual-shell-tools/grep/script-07.sh +++ b/individual-shell-tools/grep/script-07.sh @@ -4,3 +4,4 @@ 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 \ No newline at end of file diff --git a/individual-shell-tools/ls/script-01.sh b/individual-shell-tools/ls/script-01.sh index 241b62f5..71a220d8 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 diff --git a/individual-shell-tools/ls/script-02.sh b/individual-shell-tools/ls/script-02.sh index d0a5a10f..8f7eb63f 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 + diff --git a/individual-shell-tools/ls/script-03.sh b/individual-shell-tools/ls/script-03.sh index 781216d2..5161171e 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 72f3817b..a220c311 100755 --- a/individual-shell-tools/ls/script-04.sh +++ b/individual-shell-tools/ls/script-04.sh @@ -15,9 +15,11 @@ 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 -1 echo "Second exercise (sorted oldest to newest):" +ls -tr -1 + # 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. diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh index d592970f..0bd78a31 100755 --- a/individual-shell-tools/sed/script-01.sh +++ b/individual-shell-tools/sed/script-01.sh @@ -5,3 +5,5 @@ 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 \ No newline at end of file diff --git a/individual-shell-tools/sed/script-02.sh b/individual-shell-tools/sed/script-02.sh index abdd64d0..7db8a2a1 100755 --- a/individual-shell-tools/sed/script-02.sh +++ b/individual-shell-tools/sed/script-02.sh @@ -5,3 +5,5 @@ 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 \ No newline at end of file diff --git a/individual-shell-tools/sed/script-03.sh b/individual-shell-tools/sed/script-03.sh index dd284a29..9047fee4 100755 --- a/individual-shell-tools/sed/script-03.sh +++ b/individual-shell-tools/sed/script-03.sh @@ -4,3 +4,5 @@ set -euo pipefail # TODO: Write a command to output input.txt removing any line which contains a number. # The output should contain 6 lines. + +sed '/[0-9]/d' input.txt \ No newline at end of file diff --git a/individual-shell-tools/sed/script-04.sh b/individual-shell-tools/sed/script-04.sh index 0052ac6c..ae19f673 100755 --- a/individual-shell-tools/sed/script-04.sh +++ b/individual-shell-tools/sed/script-04.sh @@ -4,3 +4,5 @@ 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 \ No newline at end of file diff --git a/individual-shell-tools/sed/script-05.sh b/individual-shell-tools/sed/script-05.sh index 2dcc91a0..d9eac047 100755 --- a/individual-shell-tools/sed/script-05.sh +++ b/individual-shell-tools/sed/script-05.sh @@ -2,6 +2,7 @@ set -euo pipefail +sed 's/^\([0-9][0-9]*\) \(.*\)$/\2 \1/' input.txt # TODO: Write a command to output input.txt with one change: # 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". diff --git a/individual-shell-tools/sed/script-06.sh b/individual-shell-tools/sed/script-06.sh index 0b939017..aea80bc1 100755 --- a/individual-shell-tools/sed/script-06.sh +++ b/individual-shell-tools/sed/script-06.sh @@ -8,3 +8,5 @@ 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/,\([^ ]\)/, \1/g' input.txt \ No newline at end of file diff --git a/individual-shell-tools/wc/script-01.sh b/individual-shell-tools/wc/script-01.sh index c9dd6e5d..9cb62b7c 100755 --- a/individual-shell-tools/wc/script-01.sh +++ b/individual-shell-tools/wc/script-01.sh @@ -4,3 +4,7 @@ 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. +cd .. +cd helper-files +wc -w helper-3.txt + diff --git a/individual-shell-tools/wc/script-02.sh b/individual-shell-tools/wc/script-02.sh index 8feeb1a6..7d97b3c4 100755 --- a/individual-shell-tools/wc/script-02.sh +++ b/individual-shell-tools/wc/script-02.sh @@ -2,5 +2,9 @@ set -euo pipefail +cd .. +cd helper-files +wc -l helper-3.txt + # 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. diff --git a/individual-shell-tools/wc/script-03.sh b/individual-shell-tools/wc/script-03.sh index 6b2e9d3d..51869d04 100755 --- a/individual-shell-tools/wc/script-03.sh +++ b/individual-shell-tools/wc/script-03.sh @@ -2,6 +2,11 @@ set -euo pipefail +cd .. +cd helper-files +wc helper-*.txt + + # TODO: Write a command to output the number of lines, words, and characters in all of the files inside the helper-files directory. # The output should be something like: # 1 4 20 ../helper-files/helper-1.txt diff --git a/number-systems/README.md b/number-systems/README.md index 77a3bde9..720bcffb 100644 --- a/number-systems/README.md +++ b/number-systems/README.md @@ -5,31 +5,38 @@ 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: +1100 Convert the binary number 101101 to decimal: -Answer: +Answer: +45 Which is larger: 1000 or 0111? Answer: +1000 because its equal to 8 in decimal and 8 is larger than 7 (0111) Which is larger: 00100 or 01011? Answer: +01011 is larger What is 10101 + 01010? Answer: +11111 What is 10001 + 10001? 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: +largest number is 1111 = 15 in decimal 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: 2 bits How many bits would you need in order to store the numbers between 0 and 1000 inclusive? Answer: @@ -38,28 +45,39 @@ How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...) Answer: Convert the decimal number 14 to hex. -Answer: +Answer: E Convert the decimal number 386 to hex. -Answer: +Answer: +1- decimal to binary = 110000010 +2- then to hex = 182 Convert the hex number 386 to decimal. Answer: +using power of 16 method += (3*256)+(8*16)+6 = 768 + 128 + 6 = 902 Convert the hex number B to decimal. Answer: +11 If reading the byte 0x21 as a number, what decimal number would it mean? Answer: +33 If reading the byte 0x21 as an ASCII character, what character would it mean? 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: +dark 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: +Mix of blue and red If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be? Answer: +10101010, 00000000, 11111111 +170, 0, 255