nosleep

A tiny macOS shell script for toggling system sleep with pmset.

It is intended for cases where you need a system-level sleep toggle, including lid-closed use, rather than a temporary per-process keep-awake command.

Usage

chmod +x nosleep.sh
./nosleep.sh on
./nosleep.sh off
./nosleep.sh status
./nosleep.sh setup
./nosleep.sh help

What It Does

• on runs sudo pmset -a disablesleep 1
• off runs sudo pmset -a disablesleep 0
• status reads the current disablesleep value from pmset
• setup installs a sudoers rule so on/off stop asking for a password
• help shows the usage message

Example Scenarios

• Running a long local job or server while the Mac is closed and away from a charger.
• Allowing longer-running work such as app builds, model training, or other compute-heavy tasks to continue while you are in transit or moving between meetings.
• Keeping a remote session, file transfer, or other background task alive when normal sleep would interrupt it.
• Temporarily preventing sleep on a machine used as a small home server, lab machine, or automation host.
• Using a Mac in a setup where caffeinate is not sufficient and you intentionally need sleep disabled at the system level.

How This Differs From caffeinate

caffeinate is commonly used to keep a Mac awake while a process is running or while the display remains open, but it does not change the underlying system sleep setting in the same way.

This script uses pmset to change the system disablesleep setting directly. In practice, that means it can continue preventing sleep in situations where caffeinate is not the right tool, including lid-closed use and operation on battery power without a charger connected.

Safety

• This changes a system-level power setting, not just a single terminal session.
• If left enabled, your Mac can remain awake with the lid fully closed and while not connected to power.
• This can increase battery drain and may cause the laptop to become hot, especially if it is placed in a bag or another poorly ventilated space.
• Use it only when you intentionally need this behavior, and run off as soon as you are done.

Notes

• macOS only
• on and off use sudo, so they may prompt for an administrator password
• running the script with no arguments shows the usage message
• -a applies the setting to all power profiles

Optional Install

If you want to call it as nosleep from anywhere:

chmod +x nosleep.sh
ln -s "$(pwd)/nosleep.sh" /usr/local/bin/nosleep

The install step usually does not require a password, but creating the symlink may need one if /usr/local/bin is not writable by your user.

Skip Password Prompts

The easiest way:

./nosleep.sh setup

This creates a sudoers drop-in file for the current user. You'll enter your password once during setup — after that, on and off work without prompting.

You can also do it manually for a single user or an entire group:

# Allow all admin-group users to run pmset without password
echo "%admin ALL=(ALL) NOPASSWD: /usr/bin/pmset -a disablesleep 0, /usr/bin/pmset -a disablesleep 1" | sudo tee /etc/sudoers.d/nosleep

Or limit it to a single user:

echo "yourusername ALL=(ALL) NOPASSWD: /usr/bin/pmset -a disablesleep 0, /usr/bin/pmset -a disablesleep 1" | sudo tee /etc/sudoers.d/nosleep

This creates a drop-in file under /etc/sudoers.d/, which is safer than editing /etc/sudoers directly. The status command does not use sudo, so it is unaffected.