This skill should be used when the user asks to "create bash scripts", "automate Linux tasks", "monitor system resources", "backup files", "manage users", or "write production shell scripts". It provides ready-to-use shell script templates for system administration.
npxskills add zebbern/claude-code-guide--skill "Linux Production Shell Scripts"Loading…
Provide production-ready shell script templates for common Linux system administration tasks including backups, monitoring, user management, log analysis, and automation. These scripts serve as building blocks for security operations and penetration testing environments.
Basic Directory Backup
#!/bin/bash
backup_dir="/path/to/backup"
source_dir="/path/to/source"
# Create a timestamped backup of the source directory
tar -czf "$backup_dir/backup_$(date +%Y%m%d_%H%M%S).tar.gz" "$source_dir"
echo "Backup completed: backup_$(date +%Y%m%d_%H%M%S).tar.gz"
#!/bin/bash
source_dir="/path/to/source"
remote_server="user@remoteserver:/path/to/backup"
# Backup files/directories to a remote server using rsync
rsync -avz --progress "$source_dir" "$remote_server"
echo "Files backed up to remote server."
Backup Rotation Script
#!/bin/bash
backup_dir="/path/to/backups"
max_backups=5
# Rotate backups by deleting the oldest if more than max_backups
while [ $(ls -1 "$backup_dir" | wc -l) -gt "$max_backups" ]; do
oldest_backup=$(ls -1t "$backup_dir" | tail -n 1)
rm -r "$backup_dir/$oldest_backup"
echo "Removed old backup: $oldest_backup"
done
echo "Backup rotation completed."
Database Backup Script
#!/bin/bash
database_name="your_database"
db_user="username"
db_pass="password"
output_file="database_backup_$(date +%Y%m%d).sql"
# Perform database backup using mysqldump
mysqldump -u "$db_user" -p"$db_pass" "$database_name" > "$output_file"
gzip "$output_file"
echo "Database backup created: $output_file.gz"
CPU Usage Monitor
#!/bin/bash
threshold=90
# Monitor CPU usage and trigger alert if threshold exceeded
cpu_usage=$(top -bn1 | grep "Cpu(s)" | awk '{print $2}' | cut -d. -f1)
if [ "$cpu_usage" -gt "$threshold" ]; then
echo "ALERT: High CPU usage detected: $cpu_usage%"
# Add notification logic (email, slack, etc.)
# mail -s "CPU Alert" [email protected] <<< "CPU usage: $cpu_usage%"
fi
Disk Space Monitor
#!/bin/bash
threshold=90
partition="/dev/sda1"
# Monitor disk usage and trigger alert if threshold exceeded
disk_usage=$(df -h | grep "$partition" | awk '{print $5}' | cut -d% -f1)
if [ "$disk_usage" -gt "$threshold" ]; then
echo "ALERT: High disk usage detected: $disk_usage%"
# Add alert/notification logic here
fi
CPU Usage Logger
#!/bin/bash
output_file="cpu_usage_log.txt"
# Log current CPU usage to a file with timestamp
timestamp=$(date '+%Y-%m-%d %H:%M:%S')
cpu_usage=$(top -bn1 | grep 'Cpu(s)' | awk '{print $2}' | cut -d. -f1)
echo "$timestamp - CPU Usage: $cpu_usage%" >> "$output_file"
echo "CPU usage logged."
System Health Check
#!/bin/bash
output_file="system_health_check.txt"
# Perform system health check and save results to a file
{
echo "System Health Check - $(date)"
echo "================================"
echo ""
echo "Uptime:"
uptime
echo ""
echo "Load Average:"
cat /proc/loadavg
echo ""
echo "Memory Usage:"
free -h
echo ""
echo "Disk Usage:"
df -h
echo ""
echo "Top Processes:"
ps aux --sort=-%cpu | head -10
} > "$output_file"
echo "System health check saved to $output_file"
User Account Creation
#!/bin/bash
username="newuser"
# Check if user exists; if not, create new user
if id "$username" &>/dev/null; then
echo "User $username already exists."
else
useradd -m -s /bin/bash "$username"
echo "User $username created."
# Set password interactively
passwd "$username"
fi
Password Expiry Checker
#!/bin/bash
output_file="password_expiry_report.txt"
# Check password expiry for users with bash shell
echo "Password Expiry Report - $(date)" > "$output_file"
echo "=================================" >> "$output_file"
IFS=$'\n'
for user in $(grep "/bin/bash" /etc/passwd | cut -d: -f1); do
password_expires=$(chage -l "$user" 2>/dev/null | grep "Password expires" | awk -F: '{print $2}')
echo "User: $user - Password Expires: $password_expires" >> "$output_file"
done
unset IFS
echo "Password expiry report saved to $output_file"
Password Generator
#!/bin/bash
length=${1:-16}
# Generate a random password
password=$(openssl rand -base64 48 | tr -dc 'a-zA-Z0-9!@#$%^&*' | head -c"$length")
echo "Generated password: $password"
File Encryption Script
#!/bin/bash
file="$1"
action="${2:-encrypt}"
if [ -z "$file" ]; then
echo "Usage: $0 <file> [encrypt|decrypt]"
exit 1
fi
if [ "$action" == "encrypt" ]; then
# Encrypt file using AES-256-CBC
openssl enc -aes-256-cbc -salt -pbkdf2 -in "$file" -out "$file.enc"
echo "File encrypted: $file.enc"
elif [ "$action" == "decrypt" ]; then
# Decrypt file
output_file="${file%.enc}"
openssl enc -aes-256-cbc -d -pbkdf2 -in "$file" -out "$output_file"
echo "File decrypted: $output_file"
fi
Error Log Extractor
#!/bin/bash
logfile="${1:-/var/log/syslog}"
output_file="error_log_$(date +%Y%m%d).txt"
# Extract lines with "ERROR" from the log file
grep -i "error\|fail\|critical" "$logfile" > "$output_file"
echo "Error log created: $output_file"
echo "Total errors found: $(wc -l < "$output_file")"
Web Server Log Analyzer
#!/bin/bash
log_file="${1:-/var/log/apache2/access.log}"
echo "Web Server Log Analysis"
echo "========================"
echo ""
echo "Top 10 IP Addresses:"
awk '{print $1}' "$log_file" | sort | uniq -c | sort -rn | head -10
echo ""
echo "Top 10 Requested URLs:"
awk '{print $7}' "$log_file" | sort | uniq -c | sort -rn | head -10
echo ""
echo "HTTP Status Code Distribution:"
awk '{print $9}' "$log_file" | sort | uniq -c | sort -rn
Network Connectivity Checker
#!/bin/bash
hosts=("8.8.8.8" "1.1.1.1" "google.com")
echo "Network Connectivity Check"
echo "=========================="
for host in "${hosts[@]}"; do
if ping -c 1 -W 2 "$host" &>/dev/null; then
echo "[UP] $host is reachable"
else
echo "[DOWN] $host is unreachable"
fi
done
Website Uptime Checker
#!/bin/bash
websites=("https://google.com" "https://github.com")
log_file="uptime_log.txt"
echo "Website Uptime Check - $(date)" >> "$log_file"
for website in "${websites[@]}"; do
if curl --output /dev/null --silent --head --fail --max-time 10 "$website"; then
echo "[UP] $website is accessible" | tee -a "$log_file"
else
echo "[DOWN] $website is inaccessible" | tee -a "$log_file"
fi
done
Network Interface Info
#!/bin/bash
interface="${1:-eth0}"
echo "Network Interface Information: $interface"
echo "========================================="
ip addr show "$interface" 2>/dev/null || ifconfig "$interface" 2>/dev/null
echo ""
echo "Routing Table:"
ip route | grep "$interface"
Automated Package Installation
#!/bin/bash
packages=("vim" "htop" "curl" "wget" "git")
echo "Installing packages..."
for package in "${packages[@]}"; do
if dpkg -l | grep -q "^ii $package"; then
echo "[SKIP] $package is already installed"
else
sudo apt-get install -y "$package"
echo "[INSTALLED] $package"
fi
done
echo "Package installation completed."
Task Scheduler (Cron Setup)
#!/bin/bash
scheduled_task="/path/to/your_script.sh"
schedule_time="0 2 * * *" # Run at 2 AM daily
# Add task to crontab
(crontab -l 2>/dev/null; echo "$schedule_time $scheduled_task") | crontab -
echo "Task scheduled: $schedule_time $scheduled_task"
Service Restart Script
#!/bin/bash
service_name="${1:-apache2}"
# Restart a specified service
if systemctl is-active --quiet "$service_name"; then
echo "Restarting $service_name..."
sudo systemctl restart "$service_name"
echo "Service $service_name restarted."
else
echo "Service $service_name is not running. Starting..."
sudo systemctl start "$service_name"
echo "Service $service_name started."
fi
Directory Synchronization
#!/bin/bash
source_dir="/path/to/source"
destination_dir="/path/to/destination"
# Synchronize directories using rsync
rsync -avz --delete "$source_dir/" "$destination_dir/"
echo "Directories synchronized successfully."
Data Cleanup Script
#!/bin/bash
directory="${1:-/tmp}"
days="${2:-7}"
echo "Cleaning files older than $days days in $directory"
# Remove files older than specified days
find "$directory" -type f -mtime +"$days" -exec rm -v {} \;
echo "Cleanup completed."
Folder Size Checker
#!/bin/bash
folder_path="${1:-.}"
echo "Folder Size Analysis: $folder_path"
echo "===================================="
# Display sizes of subdirectories sorted by size
du -sh "$folder_path"/* 2>/dev/null | sort -rh | head -20
echo ""
echo "Total size:"
du -sh "$folder_path"
System Info Collector
#!/bin/bash
output_file="system_info_$(hostname)_$(date +%Y%m%d).txt"
{
echo "System Information Report"
echo "Generated: $(date)"
echo "========================="
echo ""
echo "Hostname: $(hostname)"
echo "OS: $(uname -a)"
echo ""
echo "CPU Info:"
lscpu | grep -E "Model name|CPU\(s\)|Thread"
echo ""
echo "Memory:"
free -h
echo ""
echo "Disk Space:"
df -h
echo ""
echo "Network Interfaces:"
ip -br addr
echo ""
echo "Logged In Users:"
who
} > "$output_file"
echo "System info saved to $output_file"
Git Repository Updater
#!/bin/bash
git_repos=("/path/to/repo1" "/path/to/repo2")
for repo in "${git_repos[@]}"; do
if [ -d "$repo/.git" ]; then
echo "Updating repository: $repo"
cd "$repo"
git fetch --all
git pull origin "$(git branch --show-current)"
echo "Updated: $repo"
else
echo "Not a git repository: $repo"
fi
done
echo "All repositories updated."
Remote Script Execution
#!/bin/bash
remote_server="${1:-user@remote-server}"
remote_script="${2:-/path/to/remote/script.sh}"
# Execute a script on a remote server via SSH
ssh "$remote_server" "bash -s" < "$remote_script"
echo "Remote script executed on $remote_server"
| Pattern | Purpose |
|---|---|
#!/bin/bash | Shebang for bash |
$(date +%Y%m%d) | Date formatting |
$((expression)) | Arithmetic |
${var:-default} | Default value |
"$@" | All arguments |
| Command | Purpose |
|---|---|
chmod +x script.sh | Make executable |
./script.sh | Run script |
nohup ./script.sh & | Run in background |
crontab -e | Edit cron jobs |
source script.sh | Run in current shell |
Minute(0-59) Hour(0-23) Day(1-31) Month(1-12) Weekday(0-7, 0/7=Sun)
bash -x script.sh for debugging
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Create or update AgentSkills. Use when designing, structuring, or packaging skills with scripts, references, and assets.
Set up and use 1Password CLI (op). Use when installing the CLI, enabling desktop app integration, signing in (single or multi-account), or reading/injecting/running secrets via op.
CLI to manage emails via IMAP/SMTP. Use `himalaya` to list, read, write, reply, forward, search, and organize emails from the terminal. Supports multiple accounts and message composition with MML (MIME Meta Language).