ncp – New and Improved, Now Asbestos-Free Copy Utility

Usage: ncp [option]... <SOURCE>... [DESTINATION]

Options:
-A, --acl              Preserve ACL (access control list).
-a, --archive          Archive mode (equivalent to -Dfmort).
-D                     Same as --special --devices.
    --devices          Preserve device files.
-f                     Same as --unlink=force.
-g, --group            Preserve group ownership.
-H, --hard-links       Preserve hard links.
-h, --help             Show this help message and exit.
-i, --interactive      Prompt before overwriting files.
-j, --jobs=<N>         Number of files to copy in parallel (max: 16).
-L, --follow-links     Dereference source symlinks (default when non-recursive).
-M, --move             Remove source files after copying.
-m, --mode             Preserve file permissions (mode bits).
-n                     Same as --unlink=never.
-o, --ownership        Same as --user --group.
-P, --keep-links       Preserve source symlinks (default when recursive).
-p, --progress         Show progress bar.
-r, --recursive        Copy directories recursively.
    --special          Preserve named pipes and sockets.
-T, --target=<dir>     Target directory to copy into.
-t, --time             Preserve modification time.
-U                     Same as --update=older.
    --unlink=[when]    Unlink destination before writing. [when] can be one of:
                       'never', 'always', 'force' or 'auto'.
                       If [when] is omitted, 'always' is assumed.
                       If the option is omitted entirely, 'auto' is used.
    --update=[when]    Update existing files. [when] can be one of:
                       'none', 'all', 'older', 'changed' (size or time) or 'size'.
                       If [when] is omitted, 'older' is assumed.
                       If the option is omitted entirely, all files are updated,
                       which is equivalent to --update=all.
-u, --user             Preserve user ownership.
-V, --version          Show program version and exit.
-v, --verbose          Explain what is being done.

Parameters:
SOURCE                 Files or directories to copy or move.
DESTINATION            Destination file or directory.

Usage Notes

Attributes and Permissions

By default, ncp copies just the file contents. Owner, group, permissions, modification time, and ACL are preserved only when requested with the --user, --group, --mode, --time, and --acl options respectively. Otherwise, new files receive the current time, your ownership, and default permissions (subject to umask).

Only root, or a process with the CAP_CHOWN capability, can change the owner of a file. Without it, the --user option (also implied by --ownership and --archive) has no effect and copied files are owned by you, while --group works only for groups you belong to. If --mode is also in effect, the setuid and setgid bits are removed from copies of files that belong to other users.

Symbolic Links

Symlinks in the source are followed (resolved to the file they point to) when copying non-recursively, and copied as links when copying recursively. Use the --follow-links or --keep-links option to override this default.

Symlinks at the destination are also followed, except when a source symlink is copied as a link or in move mode. In those cases, the destination symlink itself is replaced.

Recursive Mode

Directories are only copied when the --recursive option is specified. Following rsync's convention, a trailing slash on a source means "the contents of". For example:

ncp --recursive dir/ dest     # Copies the contents of dir into dest.

ncp --recursive dir  dest     # Copies dir itself, as dest/dir if dest is an
                              # existing directory, or as dest otherwise.

When recursing, device files are skipped unless the --devices option is given, and named pipes and sockets are skipped unless --special is given.

Archive Mode

The --archive option is meant for making copies, such as backups and data migration, where you want to preserve as much as possible, including attributes, symlinks, special files, and so on.

It is shorthand for -Dfmort and does not include --acl or --hard-links, which you should add manually if the destination filesystem supports them.

Move Mode

The --move option (or running the program as the nmv symlink) implies --recursive. Symlinks are moved as links and never followed. If the source and destination are on the same filesystem, items are simply renamed; otherwise they are copied and then removed.

Overwriting and Unlinking

The --unlink option controls whether an existing destination is removed before it is written:

• auto Overwrite regular files in place, preserving their inode, ownership and hard links. Replace the destination only when its type differs from the source. This is the default.

• force Like auto, but if a regular file cannot be opened for writing (for example, it is read-only), remove it and try again.

• never Do not remove anything. Regular files are overwritten in place; a destination of a different type than the source is an error.

• always Remove the destination and create a new one in its place.

Update Conditions

The --update option decides what happens when the destination already exists. Directories are not affected by this option.

• none Never overwrite existing files.

• all Always overwrite them. This is the default.

• changed Overwrite only if the size or modification time differs. Otherwise, the destination is considered up to date and its contents are not copied. Attributes are still updated (if requested) and, with --move, the source is removed.

• size Like changed, but compares only the size.

• older Overwrite only if the destination has an older modification time. Unlike changed and size, a destination that is not older than the source is skipped entirely, including attributes.

Devices, Pipes and Sockets

If a source given on the command line is a device, named pipe or socket, or if the destination is one, ncp behaves like cp, reading the data from the source and writing it to the destination.

ncp /dev/sda disk.img         # Reads the device into a regular file.
ncp disk.img /dev/sdb         # Writes the image to the device.
ncp pipe file                 # Saves whatever is written to the pipe.

This applies only to command-line arguments, never to items found while recursing, and is not used with --move.

CAUTION: If any of the --devices, --special, or --archive options are specified, ncp will copy the source itself rather than its data, replacing the destination. Likewise, with --unlink=always, a destination device will be removed and replaced instead of being written to.

Interactive Prompts

The --interactive option prompts before overwriting an existing destination. Each prompt accepts y (yes, the default), n (no), a (yes to all remaining), s (skip all remaining) or q (quit).

Parallel Execution

The --jobs option allows ncp to copy several files at the same time. This can speed up transfers on SSDs and network drives, but is unlikely to help, and may even slow things down, on mechanical hard drives.

Exit Status

• 0 Success.
• 1 Invalid arguments.
• 2 Interrupted by a signal.
• 3 One or more items could not be copied.
• 4 Copied, but some attributes could not be preserved.

Installation

Binary

Binary packages for Debian, Ubuntu, RaspberryPi and other Debian-based distributions can be installed from the CCCP Linux Package Archive. Follow their instructions to set up the archive and be sure to add the main component. After that:

sudo apt install ncp

From source

TODO

Share and enjoy.

Authors

• Dimitry Ishenko - dimitry (dot) ishenko (at) (gee) mail (dot) com

License

This project is distributed under the GNU GPL license. See the LICENSE.md file for details.