Fix failing shell tool exercises

Author: RomanSanaye

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

@@ -5,4 +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 '/London/ {print $2, $NF}' scores-table.txt;
+awk '$2 == "London" {print $1, $NF}' scores-table.txt

individual-shell-tools/cat/script-02.sh

@@ -12,4 +12,4 @@ set -euo pipefail
 # I was tempted to take a bite of it.
 # But this seemed like a bad idea...
 
-cat ../helper-files/helper-1.txt, ../helper-files/helper-2.txt, ../helper-files/helper-3.txt
+cat ../helper-files/helper-1.txt ../helper-files/helper-2.txt ../helper-files/helper-3.txt

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

@@ -4,4 +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 -iv "Hello" dialogue.txt | grep -v '^$'
+grep -iv "Hello" dialogue.txt | grep -v '^ $'