London | 26-SDC-March | Zobeir Rigi| Sprint 2 | shell-pipelines

shell-pipelines/ls-grep/script-01.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 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 +4,4 @@ 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 and doesn't contain any other upper case letters.
 # Your output should contain 7 files.
+ ls sample-files | grep '^[A-Z][^A-Z]*$'

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

@@ -4,3 +4,11 @@ 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 -c -E '^[A-Z][^A-Z]*$'
+# -c → tells grep to count matching lines instead of printing them
+
+
+# -E → enables extended regex (more flexible syntax)
+# ^[A-Z] → starts with uppercase
+# [^A-Z]* → no other uppercase letters allowed
+# $ → match the whole filename

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

@@ -5,3 +5,4 @@ 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".
+sort scores-table.txt

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

@@ -5,3 +5,4 @@ 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).
+sort -k3,3 -nr 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
+
+sort -k3,3nr scores-table.txt | head -3
+  # sort by column 3 numerically (highest first) and show top 3 lines.
+#    n(numerically) r(reverse) -k3,3 → sort by column 3 only, not the whole line, and head -3 → show the first 3 lines of the sorted output

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

@@ -5,3 +5,4 @@ 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 -k3,3 -nr scores-table.txt | head -n 2 | tail -n 1

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

@@ -6,3 +6,4 @@ 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.
+sort -u events.txt

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

@@ -5,3 +5,4 @@ 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.
+cut -d' ' -f1 events.txt | sort | uniq -c

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

@@ -6,3 +6,4 @@ 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.
+cut -d' ' -f1 events.txt | sort | uniq -c

shell-pipelines/tr/script-01.sh

@@ -6,3 +6,4 @@ 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 (.).
+tr '!' '.' < text.txt

shell-pipelines/tr/script-02.sh

@@ -7,3 +7,4 @@ 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).
+tr 'YyZz' 'ZzYy' < text.txt