genisoimage

Genisoimage is a command-line utility used to create ISO 9660 filesystem images from a directory tree. It is commonly employed to assemble CD, DVD, or Blu-ray images for distribution, backup, or archival purposes. The tool can produce standard ISO 9660 images and may include extensions such as Joliet (for Unicode filenames) and Rock Ridge (for POSIX file metadata); it can also incorporate UDF in some workflows. It supports options to create bootable ISO images and to customize volume labels, character sets, and file permissions.

Genisoimage is historically associated with forks of the widely used mkisofs tool. In many Linux distributions, it is provided as a separate package and offered as a drop-in replacement for mkisofs, while other distributions may keep mkisofs as part of the original cdrtools package. The two tools share a common command-line interface and are designed to produce compatible ISO images, though exact behavior can vary slightly across packages and versions.

Typical usage consists of specifying an output file and a source directory, along with optional features such as Joliet or Rock Ridge support. A common invocation is: genisoimage -o image.iso -R -J /path/to/source. Additional options exist to set the volume name (-V), include/exclude files, or create bootable images with El Torito parameters.

Overall, genisoimage serves as a standard utility in Unix-like systems for creating portable ISO images from filesystem trees, supporting a range of ISO and filesystem extensions to suit different distribution and archival needs.