file_operations.sh

#!/bin/bash

# Check if a filename is provided
if [ -z "$1" ]; then
  echo "Error: No file specified."
  echo "Usage: $0 <filename>"
  exit 1
fi

# Check if the file exists
if [ ! -f "$1" ]; then
  echo "Error: File '$1' does not exist."
  exit 1
fi

filename="$1"

# Task a: Count the number of characters, words, and lines
char_count=$(wc -m < "$filename")
word_count=$(wc -w < "$filename")
line_count=$(wc -l < "$filename")

echo "Task a: Count of characters, words, and lines:"
echo "Characters: $char_count"
echo "Words: $word_count"
echo "Lines: $line_count"

# Task b: File in reverse order
echo "Task b: File in reverse order:"
tac "$filename"

# Task c: Frequency of a particular word
echo "Task c: Frequency of a particular word"
echo "Enter the word to count its frequency:"
read word
word_freq=$(grep -o -i "\b$word\b" "$filename" | wc -l)
echo "The word '$word' appears $word_freq times in the file."

# Task d: Replace lower case alphabets in place of upper-case alphabets
echo "Task d: Replacing upper-case alphabets with lower-case alphabets:"
tr '[:upper:]' '[:lower:]' < "$filename"