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Command documentation sourced from the linux-command project This comprehensive command reference is part of the linux-command documentation project.

cancel-cups - CUPS Print Job Cancellation Tool

The cancel-cups command is a specialized utility for canceling print jobs in the Common UNIX Printing System (CUPS). It provides fine-grained control over print job management, allowing users and administrators to remove jobs from print queues, stop ongoing print operations, and manage printer states. This command is essential for troubleshooting printing issues, managing printer resources, and maintaining efficient print workflows in Linux environments. The tool supports both user-level job cancellation and administrative control over all print queues in the system.

Basic Syntax​

cancel-cups [OPTIONS] [DESTINATION] [JOB_ID...]

Common Options​

Job Selection Options​

  • -a - Cancel all jobs for the current user
  • -u USER - Cancel all jobs for specified user
  • -h HOST - Specify alternate CUPS server
  • -P PRINTER - Specify printer destination

Administrative Options​

  • -U USERNAME - Specify username for authentication
  • -p PASSWORD - Specify password for authentication
  • -E - Enable encryption for the connection
  • -v - Show verbose messages

Filter Options​

  • --all - Cancel all jobs (admin only)
  • --completed - Cancel completed jobs
  • --pending - Cancel pending jobs only
  • --processing - Cancel currently processing jobs

Usage Examples​

Basic Job Cancellation​

Canceling Specific Jobs​

# Cancel a specific job by ID
cancel-cups 123

# Cancel multiple jobs
cancel-cups 123 124 125

# Cancel a job on specific printer
cancel-cups -P laserjet 123

# Cancel job on remote server
cancel-cups -h printserver.example.com 123

User Job Management​

# Cancel all jobs for current user
cancel-cups -a

# Cancel all jobs for specific user
cancel-cups -u john

# Cancel all jobs for user on specific printer
cancel-cups -u jane -P office_printer

Printer-specific Operations​

# Cancel all jobs on specific printer
cancel-cups -P laserjet

# Cancel jobs on remote printer
cancel-cups -h printserver -P office_printer

# Cancel all pending jobs on printer
cancel-cups -P main_printer --pending

Administrative Operations​

System-wide Job Management​

# Cancel all jobs on system (admin only)
sudo cancel-cups --all

# Cancel all completed jobs
sudo cancel-cups --completed

# Cancel all jobs for specific user across all printers
sudo cancel-cups -u problem_user --all

# Force cancellation of processing jobs
sudo cancel-cups --processing

Remote Server Management​

# Connect to remote CUPS server with authentication
cancel-cups -h remote-server -U admin -P secret123 123

# Cancel jobs on remote server with encryption
cancel-cups -h secure-server -E -U admin 456

# Cancel all jobs on remote server
cancel-cups -h remote-server --all

Practical Examples​

Desktop User Scenarios​

Personal Print Management​

# Check current print jobs
lpq

# Cancel a mistaken print job
cancel-cups 123

# Cancel all documents I sent today
cancel-cups -a

# Cancel job stuck in queue
cancel-cups --processing 156

# Check if job was cancelled
lpstat -o 123

Multi-printer Environments​

# Cancel job on color printer (more expensive)
cancel-cups -P color_printer 789

# Move job from busy to available printer (indirect cancellation)
lpmove 789 backup_printer

# Cancel all jobs on problematic printer
cancel-cups -P problem_printer

# Cancel personal job but keep others
cancel-cups -P shared_printer -u $USER

System Administration​

Troubleshooting Print Queues​

# Check all print queues
lpstat -a

# Cancel all stuck jobs
sudo cancel-cups --all --processing

# Cancel jobs causing printer errors
sudo cancel-cups -P error_printer --all

# Clear old completed jobs to free memory
sudo cancel-cups --completed

# Monitor and automatically cancel problematic jobs
watch -n 5 "lpstat -o | grep stalled | awk '{print \$1}' | xargs -r sudo cancel-cups"
# Stop all printing for maintenance
sudo cancel-cups --all

# Cancel jobs before printer firmware update
sudo cancel-cups -P updating_printer --all

# Clear queues after network outage recovery
for printer in $(lpstat -p | cut -d' ' -f2); do
    sudo cancel-cups -P $printer --all
done

# Emergency stop for confidential document leak
sudo cancel-cups -u breach_user --all

User Print Quota Management​

# Monitor user with excessive printing
lpstat -u heavyuser

# Cancel jobs exceeding quota
sudo cancel-cups -u heavyuser --pending

# Automated quota enforcement script
#!/bin/bash
USER_LIMIT=50
for user in $(lpstat -u | grep -o '\([^)]*\)' | sort -u); do
    job_count=$(lpstat -u $user | wc -l)
    if [ $job_count -gt $USER_LIMIT ]; then
        echo "User $user exceeded quota with $job_count jobs"
        sudo cancel-cups -u $user --pending
    fi
done

Advanced Usage​

Complex Filtering and Selection​

Conditional Job Cancellation​

# Cancel jobs older than 1 hour
lpstat -o | awk '$5 < "'$(date -d '1 hour ago' '+%H:%M:%S')'" {print $1}' | xargs -r sudo cancel-cups

# Cancel large documents (>10MB)
lpstat -l | awk '/size/ && $4 > 10485760 {getline; print $1}' | xargs -r sudo cancel-cups

# Cancel jobs from specific application
lpstat -o | grep "libreoffice" | awk '{print $1}' | xargs -r cancel-cups

# Cancel jobs with specific title pattern
lpstat -o | grep "CONFIDENTIAL" | awk '{print $1}' | xargs -r sudo cancel-cups

Batch Operations​

# Cancel all jobs on printers with "error" status
lpstat -p | grep "disabled" | awk '{print $2}' | xargs -I {} sudo cancel-cups -P {}

# Move and cancel jobs in bulk
for job in $(lpstat -o -P old_printer | awk '{print $1}'); do
    echo "Moving job $job to new printer"
    lpmove $job new_printer 2>/dev/null || sudo cancel-cups $job
done

# Clean up completed jobs older than 24 hours
lpstat -W completed -o | awk '$6 < "'$(date -d '1 day ago' '+%m-%d')'" {print $1}' | xargs -r sudo cancel-cups

Integration and Automation​

Shell Scripts​

Automated Print Queue Management​

#!/bin/bash
# Advanced print queue manager with cancel-cups

LOG_FILE="/var/log/print_manager.log"
MAX_JOBS_PER_USER=20
STUCK_JOB_TIMEOUT=3600  # 1 hour

log_message() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1" >> $LOG_FILE
}

# Check for users exceeding job limits
check_user_limits() {
    for user in $(lpstat -u | grep -o '\([^)]*\)' | sort -u); do
        job_count=$(lpstat -u $user | grep -v "completed" | wc -l)
        if [ $job_count -gt $MAX_JOBS_PER_USER ]; then
            log_message "User $user exceeded limit with $job_count jobs"
            sudo cancel-cups -u $user --pending
            log_message "Cancelled pending jobs for $user"
        fi
    done
}

# Check for stuck jobs (processing too long)
check_stuck_jobs() {
    current_time=$(date +%s)
    lpstat -o | while read line; do
        if echo "$line" | grep -q "processing"; then
            job_id=$(echo $line | awk '{print $1}')
            # This is a simplified check - in reality, you'd parse the job start time
            sudo cancel-cups $job_id 2>/dev/null
            if [ $? -eq 0 ]; then
                log_message "Cancelled stuck job $job_id"
            fi
        fi
    done
}

# Main monitoring loop
while true; do
    check_user_limits
    check_stuck_jobs
    sleep 300  # Check every 5 minutes
done
#!/bin/bash
# Security-focused print job canceller

KEYWORDS="SECRET CONFIDENTIAL INTERNAL RESTRICTED"
SUSPICIOUS_USERS="guest temp test"

monitor_sensitive_jobs() {
    for keyword in $KEYWORDS; do
        lpstat -o | grep -i "$keyword" | while read line; do
            job_id=$(echo $line | awk '{print $1}')
            user=$(echo $line | grep -o '\([^)]*\)' | sed 's/[()]//g')

            log_message "ALERT: Sensitive job detected - ID: $job_id, User: $user"
            sudo cancel-cups $job_id

            # Notify security team
            echo "Print job containing '$keyword' cancelled. Job ID: $job_id, User: $user" | \
            mail -s "Print Security Alert" security@company.com
        done
    done
}

monitor_suspicious_users() {
    for user in $SUSPICIOUS_USERS; do
        job_count=$(lpstat -u $user 2>/dev/null | wc -l)
        if [ $job_count -gt 0 ]; then
            log_message "Suspicious user $user has $job_count print jobs"
            sudo cancel-cups -u $user --all
            echo "All print jobs for suspicious user $user have been cancelled" | \
            mail -s "Suspicious Print Activity" security@company.com
        fi
    done
}

Integration with Other Tools​

Log Analysis and Job Tracking​

# Integrate with CUPS error logs
tail -f /var/log/cups/error_log | grep "job" | while read line; do
    if echo "$line" | grep -qi "error\|failed\|unable"; then
        job_id=$(echo "$line" | grep -o 'job-id=[0-9]*' | cut -d'=' -f2)
        if [ -n "$job_id" ]; then
            echo "Error detected for job $job_id, cancelling..."
            sudo cancel-cups $job_id
        fi
    fi
done

# Combine with printer status monitoring
lpstat -p | grep "disabled" | awk '{print $2}' | while read printer; do
    echo "Printer $printer is disabled, cancelling jobs..."
    sudo cancel-cups -P $printer --all
done

Troubleshooting​

Common Issues​

Permission Problems​

# Permission denied when cancelling jobs
# Solution: Check user permissions and use sudo if needed
sudo cancel-cups --all

# Authentication failed with remote server
# Solution: Use correct authentication credentials
cancel-cups -h remote-server -U admin -p password 123

# SSL/TLS connection issues
# Solution: Enable encryption or check certificate
cancel-cups -h remote-server -E -U admin 123

Job Not Found​

# Job ID doesn't exist
# Solution: Check current job list first
lpstat -o
cancel-cups <correct_job_id>

# Job already completed
# Solution: Use --completed flag to remove completed jobs
sudo cancel-cups --completed

# Job on different printer
# Solution: Specify correct printer
cancel-cups -P correct_printer 123

Network Issues​

# Can't connect to CUPS server
# Solution: Check server connectivity and firewall
ping printserver.example.com
telnet printserver.example.com 631

# Remote server not responding
# Solution: Use timeout and retry logic
timeout 10 cancel-cups -h remote-server 123 || \
    echo "Server unreachable, retrying later..."

Debug Mode and Verbose Output​

Diagnostic Commands​

# Show verbose cancellation messages
cancel-cups -v 123

# Debug CUPS communication
CUPS_DEBUG_LEVEL=2 cancel-cups 123

# Check CUPS server status
lpstat -h remote-server -r

# Verify job exists before cancelling
lpstat -o 123 && cancel-cups 123

Log Monitoring​

# Monitor CUPS error log for cancellation issues
tail -f /var/log/cups/error_log | grep -i "cancel"

# Check access log for cancellation attempts
tail -f /var/log/cups/access_log | grep "CANCEL"

# Monitor system log for authentication failures
tail -f /var/log/auth.log | grep -i cups
  • lp - Submit print jobs to CUPS
  • lpq - Show printer queue status
  • lpr - Print files
  • lprm - Remove print jobs
  • lpstat - Show printer status information
  • lpadmin - Configure CUPS printers
  • lpmove - Move print jobs between printers
  • cupsdisable - Stop printers
  • cupsenable - Start printers
  • accept - Accept jobs for printers
  • reject - Reject jobs for printers

Best Practices​

  1. Always check job status before cancelling using lpstat -o
  2. Use job-specific cancellation instead of blanket cancellation when possible
  3. Verify permissions before attempting administrative cancellations
  4. Log cancellation activities for audit purposes
  5. Use authentication when connecting to remote CUPS servers
  6. Test cancellation on non-critical jobs first
  7. Implement confirmation prompts for bulk cancellation operations
  8. Monitor printer status before and after cancellation operations
  9. Use verbose mode for debugging complex cancellation scenarios
  10. Document automation scripts that include job cancellation logic

Performance Tips​

  1. Batch multiple job IDs in a single command for better performance
  2. Use user-specific cancellation (-u) instead of enumerating individual jobs
  3. Schedule maintenance during low-usage periods for bulk cancellations
  4. Cache printer lists when performing multiple operations
  5. Use connection pooling for remote server operations
  6. Implement timeout handling for network operations
  7. Prioritize stuck jobs for immediate cancellation
  8. Use grep filters to reduce the number of jobs processed
  9. Limit concurrent cancellation operations on busy servers
  10. Monitor system load during large-scale cancellation operations

The cancel-cups command is a powerful tool for managing print jobs in CUPS environments, providing both basic user-level controls and advanced administrative capabilities. Its comprehensive options and integration with other CUPS utilities make it essential for maintaining efficient and secure printing operations in Linux systems.

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