ufsd-utils

Host-side tools for UFS370 disk images.

Create, inspect, and manipulate UFS370 filesystem images used by the UFSD filesystem server on MVS 3.8j (Hercules).

Install

go install github.com/mvslovers/ufsd-utils/cmd/ufsd-utils@latest

Or build from source:

git clone https://github.com/mvslovers/ufsd-utils.git
cd ufsd-utils
go build -o ufsd-utils ./cmd/ufsd-utils

Usage

# Create a new 10MB disk image
ufsd-utils create httpd-web.img --size 10M --blksize 4096

# Show image metadata
ufsd-utils info httpd-web.img

# List root directory
ufsd-utils ls httpd-web.img /
ufsd-utils ls -l httpd-web.img /

# (coming soon)
ufsd-utils cp  ./webroot/index.html httpd-web.img:/index.html
ufsd-utils cp  -r ./webroot/css/    httpd-web.img:/css/
ufsd-utils cat httpd-web.img:/index.html
ufsd-utils mkdir httpd-web.img:/newdir
ufsd-utils rm  httpd-web.img:/oldfile.txt

Disk Format

UFS370 is a Unix V7-style filesystem adapted for MVS 3.8j. The on-disk format specification is in doc/ufsdisk-spec.md.

Key characteristics:

• Block sizes: 512–8192 bytes (default 4096)
• 128-byte inodes with EBCDIC strings and dual-format timestamps
• 64-byte directory entries (59-char filenames)
• V7-style free block chain
• Big-endian byte order (S/370 native)

Project Structure

cmd/ufsd-utils/     CLI entry point
internal/cli/       Cobra command implementations
pkg/ufs/            UFS370 format library (reusable)
pkg/ebcdic/         EBCDIC ↔ ASCII conversion
doc/                Format specification

Related Projects

• ufsd — Cross-AS filesystem server (MVS 3.8j)
• ufs370 — Original UFS370 library (MVS)
• ufs370-tools — MVS-side FORMAT tool

License

MIT