Rsync compatibility

syq rsync accepts common rsync commands for local copies, pushes, and pulls. It uses its own protocol: the remote program must be syq, not rsync. Run syq rsync --help-all for all accepted flags.

syq rsync -av project/ server:backup/project/

Differences to check before switching

Area	Syq behavior
Filters	Gitignore syntax via `--syq-ignore` / `--syq-ignore-from`; rsync filters are unsupported
Deletion timing	Extras are deleted after copying; no delete-before or delete-during mode
Positive `--max-delete N`	Deletes nothing if the plan exceeds N; rsync deletes up to N
Destination collisions	Distinct sources claiming the same destination fail before copying
`--ignore-existing`	Keeps an existing non-directory even where the source would create a directory
`--update`	Checks mtimes only for regular files; type replacements still occur
Resume	Always keeps syq partial files; cannot reuse rsync partials
Delta transfer	Reuses matching blocks at the same offsets; does not find shifted blocks
`--rsync-path PATH`	Exact syq executable path, not a shell fragment
Remote-to-remote	Refused; use native `syq cp`

A failed source or destination scan prevents deletion. A per-file read failure during transfer does not by itself prevent deletion: that source entry remains present, so its destination counterpart is not an extra. Preview deletion scope with --dry-run -v; see deletion rules.

Syq uses numeric IDs and always keeps partial files, so --numeric-ids and --partial are accepted no-ops. -P enables progress. Compression is on by default; -z does not enable anything extra. -B / --block-size changes syq’s fixed hash and resume block size.

Unsupported features

Feature	Options or syntax
Rsync filter rules	`--exclude`, `--include`, `--filter`
Hard links, ACLs, xattrs, sparse files	`-H`, `-A`, `-X`, `-S`
Backup and alternate destination trees	`--backup`, `--backup-dir`, `--suffix`, `--link-dest`, `--compare-dest`, `--copy-dest`
Following descendant links	`-L`, `--copy-links`, `--copy-unsafe-links`, `-k`, `--copy-dirlinks`, `-K`, `--keep-dirlinks`
Link filtering or rewriting	`--safe-links`, `--munge-links`
Other placement and filesystem controls	`-R` / `--relative`, `--partial-dir`, `-x` / `--one-file-system`
Early deletion	`--delete-before`, `--delete-during`, `--force`
Other comparison and output controls	`--size-only`, `-I` / `--ignore-times`, `--modify-window`, `--chmod`, `--log-file`, `-i` / `--itemize-changes`
Daemon connections	`rsync://`, `host::module`

Unsupported common flags are rejected with an explanation. Selected symlink targets are copied unchanged. --insecure-links does not enable any of the unsupported descendant-link options.

File-list parsing and help

--files-from cannot combine with syq ignore rules or deletion. A listed source whose parent is a symlink fails that entry with exit 23, without creating its implied destination parent. --insecure-links only relaxes the ownership check on symlinks in typed local paths; it does not allow symlink traversal beneath a selected source, including entries from --files-from.

Other parsing differences:

.. components are rejected rather than clamped at the source root.
dir/ and dir select the same entry. Neither selects contents unless -r is explicitly supplied; -a alone does not enable recursion here.
. and / are rejected as root entries.
Use --from0 for NUL separators; -0 is unsupported.

Blank entries and comment-looking names starting with # or ; are ignored in both separator modes. Use ./#name for a literal name. The paths are relative to one source directory; destination parents are created as needed.

-h alone does not show help; use --help or --help-all.

Syq extensions

Syq-specific options carry a --syq- prefix. Common ones are --syq-connections, --syq-ignore, --syq-ignore-from, and --syq-verify-only. The last compares selected contents without writing; it does not produce rsync’s itemized-change format.

Filters are last-match-wins with ! re-inclusion, unlike rsync’s first-match rules. Check the gitignore examples when converting a filtered command.

The compatibility tests record comparison evidence and version-specific details.

Compare without copying

syq rsync -a --syq-verify-only project/ backup/

Hashes selected contents on both sides, writes nothing, and reports DIFFERS or MISSING. Differences or inspection failures produce a nonzero exit status.