Spring Cron Expression Validator

This tool allows users to validate and preview the next few execution times of a given cron expression. It provides immediate feedback on whether a cron expression is valid and shows the next five occurrences based on the current system time.

Usage

To use the Spring Cron Expression Validator, follow these steps:

1. Run the application.
2. When prompted, enter a cron expression or type exit to quit the application.

Example Log

Enter cron expression (or type 'exit' to quit):  0  0/5 * * * *
Cron Expression:  0  0/5 * * * *
Next few instances:
2024-02-11  19:10:00
2024-02-11  19:15:00
2024-02-11  19:20:00
2024-02-11  19:25:00
2024-02-11  19:30:00
Enter cron expression (or type 'exit' to quit): e
Invalid cron expression
Enter cron expression (or type 'exit' to quit): 0
Invalid cron expression
Enter cron expression (or type 'exit' to quit): exit

Supported Cron Syntax

The validator supports the standard cron syntax with six single space-separated time and date fields. Here's a brief overview of the syntax:

• Seconds: 0-59
• Minutes: 0-59
• Hours: 0-23
• Day of Month: 1-31
• Month: 1-12 (or JAN-DEC)
• Day of Week: 0-7 (0 or 7 is Sunday, or MON-SUN)

Additionally, the validator supports the use of asterisks (*), ranges (e.g., 1-5), and steps (e.g., */5). English names for months and days of the week are also accepted.

Notes

• To run Ollama with debugging use ollama serve
• Invalid cron expressions will result in an error message indicating that the expression is invalid.
• The application will display the next five execution times for the valid cron expressions entered.

TODO

• add Native query support like 'give me every 1th november' and llm will generate cron and by validator check result and give output

HOWTO DEBUG OLLAMA

Steps:

1. git clone https://github.com/ollama/ollama.git | cd ollama
2. brew install go cmake gcc

• At build time export CGO_CFLAGS="-g"
• At runtime export OLLAMA_DEBUG=1

4. go generate ./...
5. go build .
6. OLLAMA_DEBUG=1 ./ollama serve or OLLAMA_DEBUG=1 ./ollama serve > ollama.log 2>&1