Idecapitator User Guide

Idecapitator is a command-line task manager that helps you track todos, deadlines, and events. It supports date and time input, keyword/date-based search, and automatically saves your tasks between sessions.

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Quick Start

1. Prerequisites: Ensure you have Java 17 or higher installed on your system.

   • Check your Java version: java -version
   • If you don't have Java 17+, download it from oracle.com or use OpenJDK.

2. Download the latest Idecapitator.jar from the releases page.

3. Open a terminal and navigate to the folder containing the JAR file.

4. Run the app with:

   java -jar Idecapitator.jar
   

5. Type a command and press Enter to interact with the app.

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Command Summary

Command	Format
List tasks	list
Add todo	todo DESCRIPTION
Add deadline	deadline DESCRIPTION /by DATE [TIME]
Add event	event DESCRIPTION /from DATE [TIME] /to DATE [TIME]
Mark done	mark INDEX
Unmark done	unmark INDEX
Delete task	delete INDEX
Find by keyword or date	find KEYWORD or find DATE
Exit	bye

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Date & Time Format

• Date format (input): yyyy-MM-dd e.g. 2019-12-02
• Time format (input): HHmm 24-hour e.g. 1800 for 6:00 PM
• Date format (display): MMM dd yyyy e.g. Dec 02 2019
• Time format (display): h:mma e.g. 6:00PM
• Time is optional — if omitted, it defaults to start of day and only the date is shown.

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Features

list — View all tasks

Shows all tasks currently saved with their index, type, status, and details.

list

Expected output:

    ____________________________________________________________
    Here are the tasks in your list:
    1.[T][ ] read book
    2.[D][ ] return book (by: Dec 02 2019)
    3.[E][ ] project meeting (from: Jan 10 2025, 2:00PM to: Jan 10 2025, 4:00PM)
    ____________________________________________________________

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todo — Add a Todo

Adds a simple task with no date or time attached.

todo DESCRIPTION

Example:

todo read book

Expected output:

    ____________________________________________________________
    Got it. I've added this task:
      [T][ ] read book
    Now you have 1 tasks in the list.
    ____________________________________________________________

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deadline — Add a Deadline

Adds a task with a due date, and optionally a due time.

deadline DESCRIPTION /by DATE
deadline DESCRIPTION /by DATE TIME

Examples:

deadline return book /by 2019-12-02
deadline submit assignment /by 2025-03-15 2359

Expected output:

    ____________________________________________________________
    Got it. I've added this task:
      [D][ ] return book (by: Dec 02 2019)
    Now you have 2 tasks in the list.
    ____________________________________________________________

    ____________________________________________________________
    Got it. I've added this task:
      [D][ ] submit assignment (by: Mar 15 2025, 11:59PM)
    Now you have 3 tasks in the list.
    ____________________________________________________________

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event — Add an Event

Adds a task with a start and end date/time. The end must not be before the start.

event DESCRIPTION /from DATE [TIME] /to DATE [TIME]

Examples:

event project meeting /from 2025-01-10 1400 /to 2025-01-10 1600
event overseas trip /from 2025-06-01 /to 2025-06-07

Expected output:

    ____________________________________________________________
    Got it. I've added this task:
      [E][ ] project meeting (from: Jan 10 2025, 2:00PM to: Jan 10 2025, 4:00PM)
    Now you have 4 tasks in the list.
    ____________________________________________________________

⚠️ If the end date/time is before the start date/time, an error will be shown:

    CRITICAL ERROR: Event end date/time cannot be before start date/time

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mark — Mark a Task as Done

Marks the task at the given index as completed. The status changes from [ ] to [X].

mark INDEX

Example:

mark 1

Expected output:

    ____________________________________________________________
    Nice! I've marked this task as done:
      [T][X] read book
    ____________________________________________________________

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unmark — Unmark a Task

Reverses a mark, setting the task back to not done.

unmark INDEX

Example:

unmark 1

Expected output:

    ____________________________________________________________
    Nice! I've unmarked this task:
      [T][ ] read book
    ____________________________________________________________

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delete — Delete a Task

Permanently removes the task at the given index from the list.

delete INDEX

Example:

delete 2

Expected output:

    ____________________________________________________________
    Noted. I've removed this task:
      [D][ ] return book (by: Dec 02 2019)
    Now you have 3 tasks in the list.
    ____________________________________________________________

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find — Search Tasks

Searches your task list either by keyword or by date.

Search by keyword

Returns all tasks whose description contains the keyword (case-insensitive).

find KEYWORD

Example:

find book

Expected output:

    ____________________________________________________________
    Here are the matching tasks in your list:
    1.[T][ ] read book
    2.[D][ ] return book (by: Dec 02 2019)
    ____________________________________________________________

Search by date

If you provide a valid date in yyyy-MM-dd format, it returns all deadlines due on that date and all events that span or fall on that date.

find DATE

Example:

find 2025-01-10

Expected output:

    ____________________________________________________________
    Tasks on Jan 10 2025:
    1.[E][ ] project meeting (from: Jan 10 2025, 2:00PM to: Jan 10 2025, 4:00PM)
    ____________________________________________________________

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bye — Exit the App

Exits the application. All tasks are already saved automatically — no manual save needed.

bye

Expected output:

    ____________________________________________________________
    Bye. Hope to see you again soon!
    ____________________________________________________________

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Data Storage

• Tasks are automatically saved to ./data/idecapitator.txt after every change.
• The file is created automatically if it does not exist.
• You do not need to save manually.
• Do not manually edit the data file as it may corrupt your task list.

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Error Handling

Idecapitator will show a CRITICAL ERROR message for invalid commands instead of crashing. Common errors:

Situation	Error Message
Unknown command	Unknown command: 'xyz'
Todo with no description	A todo needs a description.
Deadline missing /by	Deadlines require '/by'.
Event missing /from or /to	Events need '/from' and '/to'.
Invalid date format	Invalid date format. Please use yyyy-MM-dd (e.g., 2019-12-02)
Invalid time format	Invalid time format. Use HHmm (e.g., 1800)
Event end before start	Event end date/time cannot be before start date/time
No data file found on startup	NOTICE: No existing data found. Starting fresh!

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Troubleshooting

JAR file won't run

• Error: UnsupportedClassVersionError
  • Solution: You're using Java 16 or older. Install Java 17 or higher.
• Error: No such file or directory
  • Solution: Make sure the JAR file path is correct and you're in the right directory.

JAR not found after download

• Make sure the file downloaded completely. Check the file size matches the release.
• The JAR should be around 5-10 KB.