In-class scripting exercises

README.md

bash Scripting Exercises

1. Download the files below. Then try running the textstats.sh script with each of them.

2. Play wordle using the script below. Can you figure out

   • How to print the secret word before you start guessing? and
   • Where bash is getting the list of 5-letter words?

3. Using the fileinfo.sh script below, complete the script to display basic information about any file passed as an argument to the script. You will have to complete line 8 to begin, as well as use echo to display values to the user. BONUS: add another variable that calculates how many lines the file contains. Display the 4 file attributes.

4. Write a bash mad-lib script. Here is an AI mad-lib generator to steal from, or use ChatGPT/Gemini/etc.

5. Write a script that will fetch, decompress, and clean a TSV bundle, then convert it into a CSV file and re-compress it as a tar.gz bundle. Write it in general form so that you can pass the URL of any remote tar.gz file to it. Instructions are here.

Sample files

• Sample data - https://s3.amazonaws.com/ds2002-resources/labs/lab3-bundle.tar.gz - tar-zipped TSV
• Stock Data - https://s3.amazonaws.com/ds2002-resources/labs/stock_data.tsv - TSV
• Moby Dick - https://s3.amazonaws.com/ds2002-resources/labs/mobydick.txt (plain text)
• Flight Log - https://s3.amazonaws.com/ds2002-resources/labs/flights.csv - CSV

Resources

• Awesome bash - a collection of scripts and resources.

fileinfo.sh

#!/bin/bash

if [ $# -ne 1 ]; then
  echo "Usage: $0 <filename>"
  exit 1
fi

filename=

if [ ! -e "$filename" ]; then
  echo "Error: File '$filename' not found."
  exit 1
fi

filesize=$(ls -lh "$filename" | awk '{print $5}')
filetype=$(file "$filename" | awk -F: '{print $2}' | xargs)  # xargs removes extra whitespace
lastmod=$(date -r "$filename" "+%Y-%m-%d %H:%M:%S")
# add another var in this group that displays how many lines the file contains.

# echo out those fields:values each on its own line


exit 0

textstats.sh

#!/bin/bash

if [ $# -ne 1 ]; then
  echo "Usage: $0 <filename>"
  exit 1
fi

filename="$1"

if [ ! -f "$filename" ]; then
  echo "Error: '$filename' is not a file."
  exit 1
fi

total_words=0
line_count=0
longest_line=""
max_words=0

while IFS= read -r line; do
  line_count=$((line_count + 1))
  word_count=$(echo "$line" | wc -w)
  total_words=$((total_words + word_count))
  echo "Line $line_count: $word_count words"

  if (( word_count > max_words )); then
    max_words="$word_count"
    longest_line="Line $line_count ($word_count words)"
  fi

done < "$filename"

if (( line_count > 0 )); then  # Avoid division by zero
  average_words=$((total_words / line_count))
  echo "Average words per line: $average_words"
else
    echo "File is empty."
fi

echo "Longest line: $longest_line"

exit 0

wordle.sh

#!/bin/bash

# Thanks to GitHub user huytd for this: https://gist.github.com/huytd/6a1a6a7b34a0d0abcac00b47e3d01513

words=($(grep '^\w\w\w\w\w$' /usr/share/dict/words | tr '[a-z]' '[A-Z]'))
actual=${words[$[$RANDOM % ${#words[@]}]]} end=false guess_count=0 max_guess=6
if [[ $1 == "unlimit" ]]; then
    max_guess=999999
fi
while [[ $end != true ]]; do
    guess_count=$(( $guess_count + 1 ))
    if [[ $guess_count -le $max_guess ]]; then
        echo "Enter your guess ($guess_count / $max_guess):"
        read guess
        guess=$(echo $guess | tr '[a-z]' '[A-Z]')
        if [[ " ${words[*]} " =~ " $guess " ]]; then
            output="" remaining=""
            if [[ $actual == $guess ]]; then
                echo "You guessed right!"
                for ((i = 0; i < ${#actual}; i++)); do
                    output+="\033[30;102m ${guess:$i:1} \033[0m"
                done
                printf "$output\n"
                end=true
            else
                for ((i = 0; i < ${#actual}; i++)); do
                    if [[ "${actual:$i:1}" != "${guess:$i:1}" ]]; then
                        remaining+=${actual:$i:1}
                    fi
                done
                for ((i = 0; i < ${#actual}; i++)); do
                    if [[ "${actual:$i:1}" != "${guess:$i:1}" ]]; then
                        if [[ "$remaining" == *"${guess:$i:1}"* ]]; then
                            output+="\033[30;103m ${guess:$i:1} \033[0m"
                            remaining=${remaining/"${guess:$i:1}"/}
                        else
                            output+="\033[30;107m ${guess:$i:1} \033[0m"
                        fi
                    else
                        output+="\033[30;102m ${guess:$i:1} \033[0m"
                    fi
                done
                printf "$output\n"
            fi
        else
            echo "Please enter a valid word with 5 letters!";
            guess_count=$(( $guess_count - 1 ))
        fi
    else
        echo "You lose! The word is:"
        echo $actual
        end=true
    fi
done