While macOS shares Unix roots with Linux, its logging ecosystem differs significantly. The absence of logrotate in default installations often surprises Linux migrants. macOS uses a combination of built-in tools and third-party solutions for log management.

macOS provides two primary mechanisms for log rotation:

# 1. newsyslog (the traditional BSD-style utility)
$ man newsyslog

# 2. launchd (macOS's modern service management)
$ man launchd.plist

The /etc/newsyslog.conf file controls log rotation. Example configuration:

# Example entry format:
# logfilename [owner:group] mode count size when flags [/pid_file] [sig_num]
/var/log/app.log 644 7 * @T00 J

Key parameters:

• 7 - Keep 7 archived copies
• * - Rotate regardless of size
• @T00 - Rotate daily at midnight
• J - Use bzip2 compression

For more control, create a plist in /Library/LaunchDaemons/:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.example.logrotate</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/local/bin/logrotate</string>
        <string>/etc/logrotate.conf</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
    <key>StartCalendarInterval</key>
    <dict>
        <key>Hour</key>
        <integer>0</integer>
        <key>Minute</key>
        <integer>0</integer>
    </dict>
</dict>
</plist>

For those preferring the Linux approach:

$ brew install logrotate
$ sudo cp /usr/local/etc/logrotate.conf /etc/
$ sudo chown root:wheel /etc/logrotate.conf

Sample configuration:

/var/log/*.log {
    daily
    missingok
    rotate 14
    compress
    delaycompress
    notifempty
    create 644 root wheel
}

Test your configuration manually:

# For newsyslog
$ sudo newsyslog -v

# For logrotate
$ sudo logrotate -d /etc/logrotate.conf

While macOS shares Unix roots with Linux, its logging ecosystem differs significantly. The absence of logrotate in default installations often surprises developers coming from Linux environments. macOS employs its own logging system called asl (Apple System Logger), though many applications still write directly to log files.

macOS includes several built-in mechanisms for log management:

# View system logs
log show --predicate 'process == "myapp"'

# Configure log rotation via newsyslog
sudo nano /etc/newsyslog.conf

The newsyslog utility handles basic log rotation through its configuration file. Example entry:

/var/log/myapp.log 644 7 * @T00 J

For developers needing logrotate-like functionality:

1. Homebrew Installation: brew install logrotate
2. Custom Configuration: After installation, configure /usr/local/etc/logrotate.d/

Sample logrotate configuration for a Node.js application:

/Users/me/myapp/logs/*.log {
    daily
    missingok
    rotate 14
    compress
    delaycompress
    notifempty
    copytruncate
}

To run logrotate automatically on macOS:

# Create LaunchDaemon plist
sudo nano /Library/LaunchDaemons/com.my.logrotate.plist





    Label
    com.my.logrotate
    ProgramArguments
    
        /usr/local/bin/logrotate
        /usr/local/etc/logrotate.conf
    
    RunAtLoad
    
    StartCalendarInterval
    
        Hour
        2
        Minute
        0