A macOS and Linux command-line USB formatting tool.
v0.1.0 · by Asfandyar Choudhary

• Python 3.6+
• Root / sudo privileges

sudo bash recast.sh --install

On Linux this also auto-installs all required formatting tools (ntfs-3g, dosfstools, exfatprogs, e2fsprogs, util-linux).

On macOS this prompts you to install macFUSE + ntfs-3g via Homebrew for full NTFS read/write support. If Homebrew is not installed, Recast will install it for you first.

sudo bash recast.sh --uninstall

python3 recast.py [options]

recast                                              # interactive mode
recast --list                                       # list USB drives
recast --formats                                    # show supported formats
recast --device /dev/sdb --format ext4              # format directly
recast --device /dev/sdb --format fat32 --label MYUSB  # with label
recast --device /dev/sdb --format ntfs --yes        # skip confirmation
recast --device /dev/sdb --format ext4 --dry-run    # preview only
recast --version                                    # show version
recast --help                                       # full help

macOS uses /dev/diskN (e.g. /dev/disk2), Linux uses /dev/sdX (e.g. /dev/sdb). Always target the whole disk, not a partition (/dev/sdb not /dev/sdb1).

• Refuses to format system/internal disks
• Always requires typing YES to confirm — unless --yes is passed
• --dry-run lets you preview the exact command without running it

"Root privileges required" Always run with sudo:

sudo recast --device /dev/sdb --format ext4

"command not found: recast" after install Your PATH may not include /usr/local/bin. Add it for your shell:

# zsh (macOS default)
echo 'export PATH="/usr/local/bin:$PATH"' >> ~/.zshrc && source ~/.zshrc

# bash (Linux default)
echo 'export PATH="/usr/local/bin:$PATH"' >> ~/.bashrc && source ~/.bashrc

Drive not showing in --list (Linux) Run lsblk to confirm the kernel sees the device. If it does, pass the path directly:

sudo recast --device /dev/sdb --format fat32

Drive not showing in --list (macOS) Open Disk Utility (Cmd+Space → "Disk Utility") to confirm macOS sees the drive. Try unplugging and replugging if not.

"mkfs.X not found" (Linux) Re-run the installer to auto-install missing tools:

sudo bash recast.sh --install

"Could not unmount" (Linux) A file on the drive is open. Close it and retry, or force it:

sudo fuser -km /dev/sdb
sudo recast --device /dev/sdb --format ext4

"diskutil unmountDisk failed" (macOS) A file on the drive is open in Finder or another app. Close it and retry.

NTFS write not working after install (macOS) macFUSE requires a system restart to activate. Reboot and try again.

This project is licensed under the GNU General Public License v3.0.