London | 25-July-SDC | Pezhman Azizi | Sprint 1 | Individual Shell Tools

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.
+
+
+awk '{print $1}' scores-table.txt
+

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

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

individual-shell-tools/awk/script-04.sh

@@ -5,3 +5,4 @@ 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

individual-shell-tools/awk/script-05.sh

@@ -5,3 +5,4 @@ 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

individual-shell-tools/awk/script-06-stretch.sh

@@ -6,3 +6,4 @@ 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

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 '{total=0; for (i=3; i<=NF; i++) total += $i; print $1, total}' scores-table.txt

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

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/*.txt

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

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 -n ../helper-files/*.txt

individual-shell-tools/grep/script-01.sh

@@ -4,3 +4,5 @@ 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

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

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

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 -vi "hello" dialogue.txt

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).
+#!/bin/bash
+
+grep -B1 "cure" dialogue.txt

individual-shell-tools/grep/script-06.sh

@@ -4,3 +4,5 @@ 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

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

individual-shell-tools/ls/script-01.sh

@@ -13,3 +13,4 @@ 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

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
+

individual-shell-tools/ls/script-03.sh

@@ -5,3 +5,5 @@ 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

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 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

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

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

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
+

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

individual-shell-tools/sed/script-05.sh

@@ -6,3 +6,4 @@ 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

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 -E 's/,([^ ])/,\ \1/g' input.txt

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

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

individual-shell-tools/wc/script-03.sh

@@ -8,3 +8,4 @@ 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/*

number-systems/README.md

@@ -7,59 +7,100 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 Convert the decimal number 14 to binary.
 Answer:
 
+1110
+
 Convert the binary number 101101 to decimal:
 Answer:
 
+32,8,4,1 = 45
+
 Which is larger: 1000 or 0111?
 Answer:
 
+1000 is larger since it has more leading ones ( literally digit 1) compared to 0111. By leading one, i mean the outer most on the left side.
+
 Which is larger: 00100 or 01011?
 Answer:
 
+01011 is larger as it is got again the more leading ones ( digit 1) on the left side.
+
 What is 10101 + 01010?
 Answer:
+It is 11111
 
 What is 10001 + 10001?
 Answer:
+It is 100010
+
 
 What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
 Answer:
 
+Answer1: If representing 0 means having 0000 AS A POSSIBLE NUMBER in the range of 0 to largest number produced by four digits, then the largest possible number is when all the digits are one which makes 1111 the largest number.
+
+Answer2: If it means having 0 in one of the digits as a possible occurrence, then the largest possible number produced when zero goes to the last digit to have the least effect which  1110 the largest number.
+
 How many bits would you need in order to store the numbers between 0 and 255 inclusive?
 Answer:
 
+since 256 is 2^8 the biggest number of digits with 255 inclusive is made when we have 8 digits.
+
 How many bits would you need in order to store the numbers between 0 and 3 inclusive?
 Answer:
 
+2 bits.
+
 How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
 Answer:
 
+10 bits. since 2^n - 1 = the biggest number with n bits.
+
 How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
 Answer:
 
+if a number is a power of 2, then it has only one bit as 1 and the rest are zeros.
+
 Convert the decimal number 14 to hex.
 Answer:
+It is E
 
 Convert the decimal number 386 to hex.
 Answer:
+ox182
 
 Convert the hex number 386 to decimal.
 Answer:
+6*(16^0)+8*(16^1)+3*(16^2) = 902
 
 Convert the hex number B to decimal.
 Answer:
+It is 11
 
 If reading the byte 0x21 as a number, what decimal number would it mean?
 Answer:
+2(16^1)+1(16^0) = 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?
+If reading the byte ox21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
 Answer:
 
+Since Ox21 is 33 in decimal and we have a range of 0(black) to 255(white) in decimal, then 33 is relatively close to zero. So it the gray scale it a 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:
 
+Each set of  2 hex digits stands for each of primary colors in the following order:
+RRGGBB: comparing it to AA00FF means that we don't have any greens. so we would have a mixture of blue and red. So eventually we have shade of purpule
+
+
 If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
 Answer:
+
+So A in hex represents 10 in decimal
+And F in hex represent 15, so:
+AA => (16^0)*10 + (16^1)*10 = 10+160 = 170;
+00 => 0
+FF => (16^0)*15 + (16^1)*15 = 15+240 = 255