Update random_password.sh

Author: djeada

src/random_password.sh

@@ -1,29 +1,154 @@
 #!/usr/bin/env bash
 
 # Script Name: random_password.sh
-# Description: Script that generates a random password of the specified length.
-# Usage: random_password.sh [n]
-#       [n] - the length of the requested password
-# Example: ./random_password.sh 15
-
-main() {
-    if [ $# -ne 1 ]; then
-        echo "Usage: random_password.sh [n]"
-        echo "       [n] - the length of the requested password"
-        echo "Example: ./random_password.sh 15"
+# Description: Generates a random password with various customization options.
+#
+# Usage: random_password.sh [options]
+#
+# Options:
+#   -h, --help              Display this help message and exit.
+#   -l, --length N          Specify the length of the password (default: 12).
+#   -s, --special           Include special characters in the password.
+#   -n, --numbers           Include numbers in the password.
+#   -u, --uppercase         Include uppercase letters in the password.
+#   -e, --exclude CHARS     Exclude specific characters from the password.
+#   -c, --count N           Generate N passwords (default: 1).
+#   -r, --repeat-allowed    Allow characters to be repeated (default: true).
+#
+# Examples:
+#   ./random_password.sh --length 15 --special --numbers
+#   ./random_password.sh -l 20 -snu -e 'oO0l1I' --count 5
+#   ./random_password.sh --length 16 --no-repeat
+
+set -euo pipefail
+
+function show_help() {
+    grep '^#' "$0" | cut -c 4-
+    exit 0
+}
+
+function generate_password() {
+    local length="$1"
+    local charset="$2"
+    local repeat_allowed="$3"
+
+    if [ -z "$charset" ]; then
+        echo "Error: Character set is empty. Cannot generate password."
         exit 1
     fi
 
-    re='^[0-9]+$'
-    if ! [[ $1 =~ $re ]]; then
-        echo "Error: $1 is not an integer"
+    if [ "${#charset}" -lt "$length" ] && [ "$repeat_allowed" = false ]; then
+        echo "Error: Not enough unique characters in character set to generate a password of length $length without repeating characters."
         exit 1
     fi
 
-    password=$(strings /dev/urandom | grep -o '[[:alnum:]]' | head -n "$1" | tr -d '\n')
+    local password=""
+    if [ "$repeat_allowed" = true ]; then
+        password=$(LC_ALL=C tr -dc "$charset" </dev/urandom | head -c "$length")
+    else
+        password=$(LC_ALL=C echo "$charset" | fold -w1 | shuf | tr -d '\n' | head -c "$length")
+    fi
+
     echo "$password"
+}
+
+function main() {
+    # Default values
+    LENGTH=12
+    INCLUDE_SPECIAL=false
+    INCLUDE_NUMBERS=false
+    INCLUDE_UPPERCASE=false
+    EXCLUDE_CHARS=""
+    COUNT=1
+    REPEAT_ALLOWED=true
 
+    # Parse options
+    while [[ $# -gt 0 ]]; do
+        case "$1" in
+            -h|--help)
+                show_help
+                ;;
+            -l|--length)
+                if [[ -n "${2:-}" && "$2" =~ ^[0-9]+$ && "$2" -gt 0 ]]; then
+                    LENGTH="$2"
+                    shift 2
+                else
+                    echo "Error: --length option requires a positive integer argument."
+                    exit 1
+                fi
+                ;;
+            -s|--special)
+                INCLUDE_SPECIAL=true
+                shift
+                ;;
+            -n|--numbers)
+                INCLUDE_NUMBERS=true
+                shift
+                ;;
+            -u|--uppercase)
+                INCLUDE_UPPERCASE=true
+                shift
+                ;;
+            -e|--exclude)
+                if [[ -n "${2:-}" ]]; then
+                    EXCLUDE_CHARS="$2"
+                    shift 2
+                else
+                    echo "Error: --exclude option requires an argument."
+                    exit 1
+                fi
+                ;;
+            -c|--count)
+                if [[ -n "${2:-}" && "$2" =~ ^[0-9]+$ && "$2" -gt 0 ]]; then
+                    COUNT="$2"
+                    shift 2
+                else
+                    echo "Error: --count option requires a positive integer argument."
+                    exit 1
+                fi
+                ;;
+            -r|--repeat-allowed)
+                REPEAT_ALLOWED=true
+                shift
+                ;;
+            --no-repeat)
+                REPEAT_ALLOWED=false
+                shift
+                ;;
+            -*)
+                echo "Unknown option: $1"
+                show_help
+                ;;
+            *)
+                echo "Unknown argument: $1"
+                show_help
+                ;;
+        esac
+    done
+
+    # Build the character set
+    local charset="abcdefghijklmnopqrstuvwxyz"
+    if [ "$INCLUDE_UPPERCASE" = true ]; then
+        charset+="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    fi
+    if [ "$INCLUDE_NUMBERS" = true ]; then
+        charset+="0123456789"
+    fi
+    if [ "$INCLUDE_SPECIAL" = true ]; then
+        charset+="!\"#\$%&'()*+,-./:;<=>?@[\]^_\`{|}~"
+    fi
+
+    # Remove excluded characters
+    if [ -n "$EXCLUDE_CHARS" ]; then
+        for (( i=0; i<${#EXCLUDE_CHARS}; i++ )); do
+            charset="${charset//${EXCLUDE_CHARS:i:1}/}"
+        done
+    fi
+
+    # Generate passwords
+    for (( i=0; i<COUNT; i++ )); do
+        generate_password "$LENGTH" "$charset" "$REPEAT_ALLOWED"
+    done
 }
 
 main "$@"
-