Modifying the PATH environment variable system-wide on macOS requires deeper system integration than typical Unix systems because of Apple's launchd architecture. While ~/.bash_profile or ~/.zshrc works for terminal sessions, these changes won't propagate to:

• GUI applications launched from Finder/Dock
• Services started via launchd
• Cron jobs or other system daemons

Since macOS 10.10 (Yosemite), the recommended approach is to create a plist file that gets loaded by launchd:

sudo nano /Library/LaunchDaemons/path.plist

Then add this configuration (adjust paths as needed):

    Label
    com.user.path
    ProgramArguments
    
        /bin/launchctl
        setenv
        PATH
        /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/your/custom/path
    
    RunAtLoad
    

While still functional on older systems, /etc/launchd.conf was deprecated after macOS 10.10. If you must use it:

# /etc/launchd.conf
setenv PATH /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/your/custom/path

Important: This won't work for SIP-protected system paths on modern macOS.

To verify your changes:

# For terminal sessions:
echo $PATH

# For GUI apps:
osascript -e 'tell application "Terminal" to do script "echo $PATH"'

Common issues include:

• Permission problems with /Library/LaunchDaemons
• Path ordering conflicts
• SIP restrictions on system directories

1. Always maintain system default paths (/usr/bin:/bin:/usr/sbin:/sbin) in your PATH
2. Place custom paths before system paths when you want to override system tools
3. For single-user systems, consider ~/Library/LaunchAgents instead of system-wide changes

Setting environment variables on macOS that persist across both terminal sessions and GUI applications requires special handling. The traditional approach of modifying shell configuration files (~/.bash_profile, ~/.zshrc, etc.) only affects terminal sessions, leaving GUI apps with the default PATH.

Since macOS 10.10 Yosemite, the recommended method uses launchd configuration:

# Create or edit the launchd configuration
sudo nano /etc/paths.d/custom_path

Add your custom paths, one per line:

/usr/local/bin
/opt/homebrew/bin
~/my_apps/bin

For system-wide settings affecting all users:

sudo nano /Library/LaunchAgents/environment.plist

Add this content (adjust paths as needed):

<?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>environment</string>
    <key>ProgramArguments</key>
    <array>
        <string>/bin/launchctl</string>
        <string>setenv</string>
        <string>PATH</string>
        <string>/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/homebrew/bin</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

After making changes, either reboot or run:

launchctl load /Library/LaunchAgents/environment.plist

To verify GUI applications receive the PATH:

osascript -e 'do shell script "echo $PATH"'

When modifying system-wide PATH variables:

• Always place trusted directories first
• Avoid including user home directories in system-wide PATH
• Use absolute paths only

For dynamic PATH handling that works across environments:

if [ -x /usr/libexec/path_helper ]; then
    eval `/usr/libexec/path_helper -s`
fi
export PATH="/custom/path:$PATH"