some changes applied

Author: PooriyaKTB

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

@@ -9,3 +9,5 @@ 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.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-02.sh

@@ -16,9 +16,9 @@ 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 -t1
+ls -t1 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 -tr1
+ls -tr1 child-directory

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

@@ -6,4 +6,6 @@ set -euo pipefail
 # 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
+sed s/i/I/g ./input.txt
+
+#   **** FYI: In the line 7,it seems there is a mistake, as example for output looks like `with` is not replaced with `wIth`, but it should be replaced. ****

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

@@ -5,4 +5,7 @@ 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/" input.txt
+# as here we got only one occurance:
+sed "s/We'll/We will/" input.txt
+# But if there was more occurance, the code would be:
+sed "s/We'll/We will/g" input.txt

individual-shell-tools/sed/script-04.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