London | 25-SDC-July | Mikiyas Gebremichael | Sprint 2 | Shellpipelinesexercise

shell-pipelines/ls-grep/script-01.sh

@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of the files in the sample-files directory whose name contains at least one upper case letter.
 # Your output should contain 11 files.
+
+ls sample-files | grep '[A-Z]'

shell-pipelines/ls-grep/script-02.sh

@@ -4,3 +4,4 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of the files in the sample-files directory whose name starts with an upper case letter.
 # Your output should contain 10 files.
+ls sample-files | grep '^[A-Z]'

shell-pipelines/ls-grep/script-03.sh

@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to output the names of the files in the sample-files directory whose name starts with an upper case letter and doesn't contain any other upper case letters.
 # Your output should contain 7 files.
+ls sample-files | grep '^[A-Z][^A-Z]*$'
+#[^A-Z] is any character that is not an uppercase letter ,$ means end of the line.

shell-pipelines/ls-grep/script-04.sh

@@ -4,3 +4,5 @@ set -euo pipefail
 
 # TODO: Write a command to count the number of files in the sample-files directory whose name starts with an upper case letter and doesn't contain any other upper case letters.
 # Your output should be the number 7.
+ls sample-files | grep -E '^[A-Z][^A-Z]*$' | wc -l
+#counts the number of matching lines/files.

shell-pipelines/sort-uniq-head-tail/script-01.sh

@@ -5,3 +5,6 @@ set -euo pipefail
 # The input for this script is the scores-table.txt file.
 # TODO: Write a command to output scores-table.txt, with lines sorted by the person's name.
 # The first line of your output should be "Ahmed London 1 10 4" (with no quotes). And the third line should be "Chandra Birmingham 12 6".
+
+#ANSWER
+sort ./scores-table.txt

shell-pipelines/sort-uniq-head-tail/script-02.sh

@@ -5,3 +5,5 @@ set -euo pipefail
 # The input for this script is the scores-table.txt file.
 # TODO: Write a command to output scores-table.txt, with lines sorted by the person's first score, descending.
 # The first line of your output should be "Basia London 22 9 6" (with no quotes).
+#ANSWER
+sort -rnk3 scores-table.txt

shell-pipelines/sort-uniq-head-tail/script-03.sh

@@ -8,3 +8,7 @@ set -euo pipefail
 # Basia London 22 9 6
 # Piotr Glasgow 15 2 25 11 8
 # Chandra Birmingham 12 6
+#ANSWER
+sort -rnk3 scores-table.txt | head -n 3
+
+#head -n 3 tells it to take the top 3 values by numerically

shell-pipelines/sort-uniq-head-tail/script-04.sh

@@ -5,3 +5,7 @@ set -euo pipefail
 # The input for this script is the scores-table.txt file.
 # TODO: Write a command to output scores-table.txt, with shows the line for the player whose first score was the second highest.
 # Your output should be: "Piotr Glasgow 15 2 25 11 8" (without quotes).
+
+sort -rnk3 scores-table.txt | sed -n '2p'
+
+#sed -n '2p' is print the second line of the sorted output

shell-pipelines/sort-uniq-head-tail/script-05.sh

@@ -6,3 +6,5 @@ set -euo pipefail
 # TODO: Write a command to show a list of all events that have happened, without duplication.
 # The order they're displayed doesn't matter, but we never want to see the same event listed twice.
 # Your output should contain 6 lines.
+#ANSWER
+sort events.txt | uniq

shell-pipelines/sort-uniq-head-tail/script-06.sh

@@ -5,3 +5,7 @@ set -euo pipefail
 # The input for this script is the events.txt file.
 # TODO: Write a command to show how many times anyone has entered and exited.
 # It should be clear from your script's output that there have been 5 Entry events and 4 Exit events.
+
+#ANSWER
+echo "Entry events: $(grep -c 'Entry' events.txt)"
+echo "Exit events: $(grep -c 'Exit' events.txt)"

shell-pipelines/sort-uniq-head-tail/script-07.sh

@@ -6,3 +6,6 @@ set -euo pipefail
 # TODO: Write a command to show how many times anyone has entered and exited.
 # It should be clear from your script's output that there have been 5 Entry events and 4 Exit events.
 # The word "Event" should not appear in your script's output.
+#ANSWER
+echo "Entries: $(grep -c 'Entry'  events-with-timestamps.txt)"
+echo "Exits: $(grep -c 'Exit' events-with-timestamps.txt)"

shell-pipelines/tr/script-01.sh

@@ -6,3 +6,7 @@ set -euo pipefail
 # The author got feedback that they're using too many exclamation marks (!).
 #
 # TODO: Write a command to output the contents of text.txt with every exclamation mark (!) replaced with a full-stop (.).
+
+#ANSWER
+tr '!' '.' <text.txt
+#replace ! by . then save it to the text.txt file

shell-pipelines/tr/script-02.sh

@@ -7,3 +7,7 @@ set -euo pipefail
 # so every Y should be a Z, and every Z should be a Y!
 #
 # TODO: Write a command to output the contents of text.txt with every Y and Z swapped (both upper and lower case).
+
+#ANSWER
+tr 'yYzZ' 'zZyY' < text.txt
+#eg replace y by z , Y by Z ... and do this char by char basis. then put down the updated version on the file.