are_anagrams.sh

#!/usr/bin/env bash

# Script Name: are_anagrams.sh
# Description: Checks if two or more strings are anagrams of each other.
#              Supports various options to customize comparison behavior.
# Usage: ./are_anagrams.sh [options] [string1 string2 ...]
# Options:
#   -i, --ignore-case        Ignore case differences.
#   -s, --ignore-spaces      Ignore spaces and line breaks.
#   -p, --ignore-punctuation Ignore punctuation marks.
#   -u, --unicode            Handle Unicode characters.
#   -f, --file FILE          Read strings from a file (one per line).
#       --stdin              Read strings from standard input.
#   -v, --verbose            Enable verbose output.
#   -h, --help               Display this help message.
# Examples:
#   ./are_anagrams.sh -i "Listen" "Silent"
#   ./are_anagrams.sh -i -s -f strings.txt
#   echo -e "Dormitory\nDirty room" | ./are_anagrams.sh -i --stdin

# Exit immediately if a command exits with a non-zero status.
set -e

# Default configurations
IGNORE_CASE=false
IGNORE_SPACES=false
IGNORE_PUNCTUATION=false
HANDLE_UNICODE=false
VERBOSE=false
INPUT_STRINGS=()
READ_FROM_FILE=false
INPUT_FILE=""
READ_FROM_STDIN=false

# Function to display usage information
usage() {
    echo "Usage: $0 [options] [string1 string2 ...]
Options:
  -i, --ignore-case        Ignore case differences.
  -s, --ignore-spaces      Ignore spaces and line breaks.
  -p, --ignore-punctuation Ignore punctuation marks.
  -u, --unicode            Handle Unicode characters.
  -f, --file FILE          Read strings from a file (one per line).
      --stdin              Read strings from standard input.
  -v, --verbose            Enable verbose output.
  -h, --help               Display this help message."
}

# Function for verbose logging
log() {
    if [[ "$VERBOSE" = true ]]; then
        echo "$1"
    fi
}

# Parse command-line arguments
ARGS=()
while [[ "$#" -gt 0 ]]; do
    case "$1" in
        -i|--ignore-case)
            IGNORE_CASE=true
            shift
            ;;
        -s|--ignore-spaces)
            IGNORE_SPACES=true
            shift
            ;;
        -p|--ignore-punctuation)
            IGNORE_PUNCTUATION=true
            shift
            ;;
        -u|--unicode)
            HANDLE_UNICODE=true
            shift
            ;;
        -f|--file)
            READ_FROM_FILE=true
            INPUT_FILE="$2"
            shift 2
            ;;
        --stdin)
            READ_FROM_STDIN=true
            shift
            ;;
        -v|--verbose)
            VERBOSE=true
            shift
            ;;
        -h|--help)
            usage
            exit 0
            ;;
        -*)
            echo "Unknown option: $1"
            usage
            exit 1
            ;;
        *)
            ARGS+=("$1")
            shift
            ;;
    esac
done

# Collect input strings
if [[ "$READ_FROM_FILE" = true ]]; then
    if [[ ! -f "$INPUT_FILE" ]]; then
        echo "Error: File '$INPUT_FILE' not found."
        exit 1
    fi
    while IFS= read -r line; do
        INPUT_STRINGS+=("$line")
    done < "$INPUT_FILE"
elif [[ "$READ_FROM_STDIN" = true ]]; then
    while IFS= read -r line; do
        INPUT_STRINGS+=("$line")
    done
else
    INPUT_STRINGS+=("${ARGS[@]}")
fi

# Check if at least two strings are provided
if [[ ${#INPUT_STRINGS[@]} -lt 2 ]]; then
    echo "Error: At least two strings must be provided."
    usage
    exit 1
fi

# Function to clean and sort a string
sort_string() {
    local string="$1"

    # Remove spaces if needed
    if [[ "$IGNORE_SPACES" = true ]]; then
        string=$(echo "$string" | tr -d '[:space:]')
    fi

    # Remove punctuation if needed
    if [[ "$IGNORE_PUNCTUATION" = true ]]; then
        string=$(echo "$string" | tr -d '[:punct:]')
    fi

    # Convert to lower case if needed
    if [[ "$IGNORE_CASE" = true ]]; then
        if [[ "$HANDLE_UNICODE" = true ]]; then
            string=$(echo "$string" | awk '{print tolower($0)}')
        else
            string=$(echo "$string" | tr '[:upper:]' '[:lower:]')
        fi
    fi

    # Split into characters, sort, and reassemble
    if [[ "$HANDLE_UNICODE" = true ]]; then
        # For Unicode, use sed and sort with appropriate locale
        # Assume locale is set properly
        sorted_string=$(echo "$string" | sed 's/./&\n/g' | LC_ALL=C sort | tr -d '\n')
    else
        # For ASCII, use grep -o .
        sorted_string=$(echo "$string" | grep -o . | LC_ALL=C sort | tr -d '\n')
    fi

    echo "$sorted_string"
}

# Main comparison logic
first_string="${INPUT_STRINGS[0]}"
first_string_sorted=$(sort_string "$first_string")
log "First string sorted: $first_string_sorted"

for ((i=1; i<${#INPUT_STRINGS[@]}; i++)); do
    current_string="${INPUT_STRINGS[i]}"
    current_string_sorted=$(sort_string "$current_string")
    log "Current string sorted: $current_string_sorted"
    if [[ "$first_string_sorted" != "$current_string_sorted" ]]; then
        echo "The strings are not anagrams."
        exit 0
    fi
done

echo "The strings are anagrams."