Cron Scheduler

Manage cron jobs on macOS/Linux - list, add, remove, backup, and schedule recurring tasks

Security Scan

The skill's requested actions and included script align with its stated purpose (managing a user's cron jobs); no unexplained credential or network access is requested, though the script contains some bugs/rough edges you should review before running as your user or with sudo.

Purpose & Capability

Name/description match the provided files. The script manipulates the user's crontab, manages backups under $HOME/.cron-backups, and uses sudo only for service start/stop—these are coherent with a cron-management tool.

Instruction Scope

SKILL.md and README instruct the agent/user to make the script executable and optionally add it to PATH; runtime instructions and script operations stay within cron management (reading/modifying crontab, writing backups under HOME, calling systemctl/launchctl with sudo). No instructions attempt to read unrelated files, external credentials, or send data off-host. Note: the script will launch an editor for 'edit' and prompts for confirmation on restore.

Install Mechanism

Instruction-only skill with an included shell script; no install spec or remote downloads. Low installer risk because nothing is fetched or executed automatically from external sources.

Credentials

No environment variables or credentials are requested. The script uses $HOME and standard commands (crontab, systemctl/launchctl) which are appropriate for its function. It may invoke sudo for service control, which is expected for starting/stopping system daemons.

Persistence & Privilege

always is false and the skill does not request persistent elevated privileges. It writes backups to a user-owned directory and does not modify other skills or global agent config.

Assessment

This skill appears coherent with its purpose, but review the included script before running: 1) Inspect scripts/cron-helper.sh locally for any unexpected commands. 2) Be aware service start/stop calls use sudo and will prompt for your password; only run those if you expect to control system services. 3) The script has some minor code-quality issues (cron expression validation is basic and the 'remove by line' logic looks fragile); test additions/removals on a non-critical account and verify backups in ~/.cron-backups before restoring. 4) If you don't trust the author or source, run the script in a sandbox or manually implement the small operations you need instead of granting execution rights.

Cron Scheduler Skill

A comprehensive skill for managing cron jobs on both macOS and Linux systems.

Features

1. List Jobs - View all cron jobs for the current user
2. Add Job - Create new cron jobs with schedule validation
3. Remove Job - Delete jobs by line number or pattern
4. Edit Crontab - Open crontab in your default editor
5. Next Runs - See when each job will execute next
6. Backup/Restore - Safely backup and restore crontab configurations
7. Service Control - Start/stop/status of cron daemon
8. Templates - Common schedule patterns for quick setup

Requirements

• crontab command (pre-installed on macOS/Linux)
• bash shell
• Optional: cronnext for accurate next-run predictions (Linux)

Installation

# Make the script executable
chmod +x ~/.openclaw/workspace/skills/cron-scheduler/scripts/cron-helper.sh

# Optional: Add to PATH
echo 'export PATH="$HOME/.openclaw/workspace/skills/cron-scheduler/scripts:$PATH"' >> ~/.zshrc
source ~/.zshrc

Usage

List all cron jobs

cron-scheduler list
# or
cron-scheduler l

Add a new cron job

# Daily backup at 2am
cron-scheduler add "0 2 * * *" "~/scripts/backup.sh"

# Every hour
cron-scheduler add "0 * * * *" "~/scripts/hourly-task.sh"

# Every 5 minutes
cron-scheduler add "*/5 * * * *" "~/scripts/monitor.sh"

Remove cron jobs

# By line number (use 'list' first to see line numbers)
cron-scheduler remove 3

# By pattern (matches anywhere in the line)
cron-scheduler removep "backup"

Edit crontab directly

cron-scheduler edit
# or
cron-scheduler e

Show next run times

cron-scheduler next
# or
cron-scheduler n

Backup and restore

# Create backup
cron-scheduler backup

# List available backups
cron-scheduler restore

# Restore specific backup
cron-scheduler restore ~/.cron-backups/crontab_20240315_143022.bak

Manage cron service

# Check status
cron-scheduler service status

# Start cron (may require sudo)
cron-scheduler service start

# Stop cron (may require sudo)
cron-scheduler service stop

View templates

cron-scheduler templates
# or
cron-scheduler t

Cron Schedule Format

┌──────────── minute (0 - 59)
│ ┌────────── hour (0 - 23)
│ │ ┌──────── day of month (1 - 31)
│ │ │ ┌------ month (1 - 12)
│ │ │ │ ┌---- day of week (0 - 6, Sunday=0)
* * * * *

Common Examples

Schedule	Description
0 0 * * *	Daily at midnight
0 2 * * *	Daily at 2am
0 * * * *	Every hour
*/5 * * * *	Every 5 minutes
0 9 * * 1-5	Weekdays at 9am
0 0 * * 0	Weekly on Sunday
0 0 1 * *	Monthly on 1st

Platform Support

• macOS: Uses launchctl for service management
• Linux: Uses systemctl for service management

Safety Features

• Temporary files used for atomic crontab modifications
• Backup created before any destructive operations
• Confirmation prompt before restore
• Schedule validation before adding jobs