shred — secure file overwrite utility

A lightweight, cross-compatible secure file overwrite utility written in shell.

Originally, shred is not natively available on macOS systems. This project was created to provide similar functionality for macOS users, while remaining fully compatible across Linux and other Unix-like environments.

Usage

shred [-v] [-n N] [-z] [-k] FILE|DIR

Options

• -v Verbose output
• -n N Number of random overwrite passes (default: 3)
• -z Perform a final overwrite with zeros
• -k Keep files after overwriting
• -h Show help message

Examples

shred -n 3 -z /path/to/file
shred -v /path/to/dir
shred -n 1 -k ./somefile.txt

Notes

• Overwrites files in-place and (when supported) restores original file size.
• Skips non-regular files.
• Not guaranteed to erase data on SSDs, copy-on-write filesystems, snapshots, backups, or remote storage.
• Requires write permission; use sudo if necessary.

Install

Run the provided installer.sh to install system-wide or per-user:

chmod +x ./installer.sh

./installer.sh
./installer.sh --system
./installer.sh --user

Uninstall

# system (if installed system-wide)
sudo rm /usr/local/bin/shred

# user (if installed to ~/.local/bin)
rm "$HOME/.local/bin/shred"

License

MIT License

Copyright (c) 2026 Michael Rogers

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.