genisoimage -R -J -V "MyVolume" -o output.iso iso_contents/ #!/bin/bash PKG="$1" OUT="$2:-output.iso" TMPDIR=$(mktemp -d) echo "Extracting $PKG ..." xar -xf "$PKG" -C "$TMPDIR" cd "$TMPDIR"
if [ -f "Payload" ]; then echo "Decompressing Payload ..." cat Payload | gunzip -dc | cpio -i 2>/dev/null || pbzx -n Payload | cpio -i fi
pbzx -n Payload | cpio -i For a macOS installer ISO, copy the extracted contents into a folder that mimics a bootable installer (e.g., copy Install macOS.app contents). For a simple data ISO, skip this. how to convert pkg to iso
cd pkg_extracted cat Payload | gunzip -dc | cpio -i
hdiutil makehybrid -iso -joliet -o output.iso iso_contents/ genisoimage -R -J -V "MyVolume" -o output
Unless you specifically need ISO 9660 for an optical disc or legacy VM, consider converting to .dmg (macOS native) or .tar.gz (cross-platform) after extraction.
iso_contents/ Applications/ (if macOS installer) Library/ System/ usr/ .IABootFiles (for bootability) On macOS: how to convert pkg to iso
echo "Creating ISO ..." hdiutil makehybrid -iso -joliet -o "$OUT" .
Example structure: