Task 2: Configure CLI tools and Bash scripting

tasks/module_4/task-2/data/users.db

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+baer,baer
+temp,temp
+asd,qweq
+qweqweqwe,qweqweqwe

tasks/module_4/task-2/scripts/db.sh

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+#!/bin/bash
+
+source "./helpers/help_db.sh"
+source "./helpers/add_user_db.sh"
+source "./helpers/backup_db.sh"
+source "./helpers/restore_db.sh"
+source "./helpers/list_users_db.sh"
+source "./helpers/find_user_db.sh"
+
+DB_FILE_PATH="../data/users.db"
+USERNAME_OR_INVERSE_FLAG=$2;
+
+case $1 in
+  add)            add "$DB_FILE_PATH" ;;
+  backup)         backup "$DB_FILE_PATH" ;;
+  restore)        restore "$DB_FILE_PATH" ;;
+  find)           find "$DB_FILE_PATH" "$USERNAME_OR_INVERSE_FLAG" ;;
+  list)           list "$DB_FILE_PATH" "$USERNAME_OR_INVERSE_FLAG" ;;
+  help | '' | *)  help ;;
+esac

tasks/module_4/task-2/scripts/helpers/add_user_db.sh

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+# add_user_db.sh
+
+add() {
+  local _DB_FILE_PATH="$1"
+  while true; do
+    read -p "Type the username (latin letters only) of a new entity: " _username
+    if [[ "$_username" =~ ^[a-zA-Z]+$ ]]; then
+        break
+    else
+        echo "Incorrect input, latin letters only"
+        exit 1
+    fi
+  done
+  while true; do
+    read -p "Type a role (latin letters only): " _role
+    if [[ "$_role" =~ ^[a-zA-Z]+$ ]]; then
+        break
+    else
+        echo "Incorrect iput, litin letters only"
+        exit 1
+    fi
+  done
+  echo "$_username,$_role" >> "$_DB_FILE_PATH"
+  echo "Data saved to $_DB_FILE_PATH"
+}

tasks/module_4/task-2/scripts/helpers/backup_db.sh

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+# backup_db.sh
+
+backup() {
+  local DB_FILE_PATH="$1"
+  local current_date=$(date +'%Y-%m-%d')
+  local backup_file="../data/$current_date-users.db.backup"
+  cp "$DB_FILE_PATH" "$backup_file"
+  echo "Backup created as $backup_file"
+}

tasks/module_4/task-2/scripts/helpers/find_user_db.sh

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+#find_user_db.sh
+
+function find {
+  local DB_FILE_PATH="$1"
+  if [ -n "$2" ]; then
+    local USERNAME_TO_FIND="$2"
+    if [ -f "$DB_FILE_PATH" ]; then
+        found_entries=$(awk -v username="$USERNAME_TO_FIND" -F',' '$1 == username' "$DB_FILE_PATH")
+        if [ -n "$found_entries" ]; then
+            echo "$found_entries"
+        else
+            echo "User not found."
+        fi
+    else
+        echo "Database file not found."
+        exit 1
+    fi
+  else
+    echo "Usage: db.sh find <username>"
+    exit 1
+  fi
+}

tasks/module_4/task-2/scripts/helpers/help_db.sh

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+function help {
+  echo "Manages users in db. It accepts a single parameter with a command name."
+  echo
+  echo "Syntax: db.sh [command]"
+  echo
+  echo "List of available commands:"
+  echo
+  echo "add           Adds a new line to the users.db. Script must prompt user to type a
+              username of new entity. After entering username, user must be prompted to
+              type a role."
+  echo "backup        Creates a new file, named" $filePath".backup which is a copy of
+              current" $fileName
+  echo "restore       Restores the database from a previously created backup. If a backup file
+              with the current date exists, it will be used to overwrite the current
+              database. If no backup file is found, the script will inform you that no
+              backup file is available for restoration."
+  echo "find          Prompts user to type a username, then prints username and role if such
+              exists in users.db. If there is no user with selected username, script must print:
+              “User not found”. If there is more than one user with such username, print all
+              found entries."
+  echo "list          Prints the contents of users.db in the format: N. username, role
+              where N is the line number of an actual record. By default, it lists the records
+              in ascending order. You can use the additional optional parameter --inverse to
+              reverse the order and list the records from bottom to top. For example, running
+              the command "\$ db.sh list --inverse" will return the result as follows:
+
+              \`$ db.sh list --inverse\`
+
+              10. John, admin
+              9. Valerie, user
+              8. Ghost, guest"
+}

tasks/module_4/task-2/scripts/helpers/list_users_db.sh

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+#list_users_db.sh
+
+function list () {
+  local _DB_FILE_PATH="$1"
+  local _INVERSE_FLAG="$2"
+  if [ "$_INVERSE_FLAG" == "--inverse" ]; then
+    awk -F',' '{data[NR] = $1 ", " $2} END {for (i = NR; i >= 1; --i) print i ". " data[i]}' "$_DB_FILE_PATH"
+  else
+    awk '{print NR ". " $1 ", " $2}' FS=',' "$_DB_FILE_PATH"
+  fi
+}

tasks/module_4/task-2/scripts/helpers/restore_db.sh

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+# restore_db.sh
+
+restore() {
+  local _DB_FILE_PATH="$1"
+  current_date=$(date +'%Y-%m-%d')
+  backup_file="../data/$current_date-users.db.backup"
+  if [ -f "$backup_file" ]; then
+    cp "$backup_file" "$_DB_FILE_PATH"
+    echo "Restored from $backup_file"
+  else
+    echo "No backup file found for restoration."
+  fi
+}