Read-only filesystem preflight / v0.1.0
Scan source and destination metadata, settle overwrite conflicts, and budget sparse-file uncertainty before a long file operation can strand your archive.
cargo install file-change-space-check
01 Scan metadata
02 Apply policy
03 Check headroom
04 Emit manifest
Policy simulator
This browser demo uses a fixed example; your files never enter the page. Change the free space and conflict rule to see the plan recompute.
The overwrite is staged before 5.9 GB can be reclaimed. The upper bound exceeds available space by 5.6 GB.
Action manifest 3 entries
What the number means
Read sizes, allocated blocks, entry types, and destination availability. Never read file contents by default.
Apply overwrite, skip, or keep-both to every relative path in lexical order.
Report sparse files as a lower–upper range. The safer upper bound controls the verdict.
Print a human check or portable JSON manifest. It remains a plan, never an executable script.
Small surface, useful output
cp, not inside it.The tool plans source directory contents into a destination root. It does not attempt to guess your copy command or permissions.
Read the source on GitHub$ fcsc ./camera-roll /mnt/archive \
--policy overwrite --json
"verdict": "insufficient",
"required_headroom_bytes_upper": 23192823398,
"conflicts": 1
# exit 2 · no files changedHonest limits