iso-kit

Work with ISO disk images in Go — or straight from the command line.

Open an ISO and pull files out of it. Change what's inside and save it back. Build a brand-new image from a folder, including ones that boot on real hardware from a USB stick.

Command line tools

go install github.com/bgrewell/iso-kit/cmd/isoextract@latest
go install github.com/bgrewell/iso-kit/cmd/isocreate@latest
go install github.com/bgrewell/iso-kit/cmd/isoview@latest

Extract an ISO:

isoextract -o ./extracted ubuntu-24.04.iso

Build an ISO from a folder:

isocreate -V "MY_BACKUP" -o backup.iso ./my-files

Build a bootable, USB-writable ISO:

isocreate -V "MY_LINUX" -o my-linux.iso \
  --bios-boot isolinux/isolinux.bin \
  --efi-boot EFI/BOOT/efiboot.img \
  --isohybrid-mbr isohdpfx.bin --gpt \
  ./my-linux-root

Look inside an ISO:

isoview ubuntu-24.04.iso

Using the library

go get github.com/bgrewell/iso-kit

import "github.com/bgrewell/iso-kit/pkg/iso9660"

// Open an ISO and read a file out of it.
f, _ := os.Open("image.iso")
img, _ := iso9660.Open(f)
data, _ := img.ReadFile("docs/readme.txt")

// Change it and save a new copy.
img.AddFile("extras/new-file.txt", []byte("added!\n"))
img.RemoveFile("obsolete.txt")
out, _ := os.Create("modified.iso")
img.Save(out)

// Or build one from scratch.
img, _ := iso9660.Create("MYVOLUME")
img.AddLocalDirectory("./payload", "/")
out, _ := os.Create("new.iso")
img.Save(out)

That's the whole core loop: Open or Create, change things, Save. Long filenames, mixed case, permissions, and symlinks are preserved automatically (Rock Ridge is on by default). See the usage guide for bootable images, Windows-friendly naming (Joliet), and everything else.

What it supports

	Read	Write
ISO 9660	✅	✅
Rock Ridge — POSIX names, permissions, symlinks	✅	✅
Joliet — Windows Unicode names	✅	✅
El Torito — BIOS + EFI boot	✅	✅
Hybrid MBR/GPT — boots from USB	✅	✅
Files over 4 GiB (multi-extent)	✅	—
UDF	✅	—

Output is verified against independent tools (xorriso, fdisk, parted) in CI.

Documentation

• Usage guide — the full tour: options, bootable images, modifying existing ISOs, CLI reference, limitations
• Architecture — how the library works inside, for contributors
• Roadmap — what's done and what's planned

The API is pre-1.0 and may still change between releases.