NAME

copyfilerange - copy range(s) from source to destination file

SYNOPSIS

copyfilerange [options] source destination range...

DESCRIPTION

The copyfilerange command copies byte ranges from source to destination file. It is a wrapper around the copy_file_range(2) system call.

The command can be used to create files with unallocated gaps (sparse files) and/or with shared blocks between multiple files (reflinks).

Each range is of the form source_offset:destination_offset:length, with all values in bytes. If length is 0, then as much data as is available is copied. Multiple ranges may be supplied.

When one or both of the offsets are omitted, the operation uses the last-used file location, starting with 0.

OPTIONS

-r, --ranges file

-v, --verbose

-h, --help

-V, --version

EXIT STATUS

0

1

NOTES

The copy_file_range(2) system call has some serious caveats: the source and destination files must use the same filesystem type, and some virtual filesystems (like procfs) won’t work. copy_file_range(2) will use reflinks when the filesystem supports this. To use reflinks, the file range most often needs to align with the filesystem block size on both the source and destination file.

AUTHORS

Dick Marinus <dick@mrns.nl>

EXAMPLES

copyfilerange original-file reflink ::
copyfilerange original-file first-block ::4096
copyfilerange original-file even-blocks -r <(seq 0 8192 40960|awk '{print $1"::4096"}')
copyfilerange original-file sparse-file 0:1M:1
copyfilerange original-file split-first-mb ::1M
copyfilerange original-file split-remainder 1M::
copyfilerange split-first-mb join ::
copyfilerange split-remainder join 1M::

SEE ALSO

copy_file_range(2)

REPORTING BUGS

For bug reports, use the issue tracker https://github.com/util-linux/util-linux/issues.

AVAILABILITY

The copyfilerange command is part of the util-linux package which can be downloaded from Linux Kernel Archive https://www.kernel.org/pub/linux/utils/util-linux/.