> Historic versions of the cp utility had an -r option. This implementation supports that option; however, its use is strongly discouraged, as it does not correctly copy special files, symbolic links or FIFOs.
from the lstat man page:
The lstat() function is identical to stat() except when the named file is
a symbolic link, in which case lstat() returns information about the link
itself, not the file the link references.
$ tree test1
test1
|-- file.txt
`-- link.txt -> ../link.txt
0 directory, 2 files
$ cp -r test1 test2
$ tree test2
test2
|-- file.txt
`-- link.txt
0 directory, 2 files
$ cp -R test1 test3
$ tree test3
test3
|-- file.txt
`-- link.txt -> ../link.txt
0 directory, 2 files
$ cp -RL test1 test4
$ tree test4/
test4/
|-- file.txt
`-- link.txt
0 directory, 2 filesThe snippet of code makes it very clear what the difference is, no?
flag_copy_as_regular = 1 VS flag_copy_as_regular = 0, where regular would be a "regular" and not "special" file.
Sprite 2.077 pc386
Welcome to Sprite
root@cherimoya [1] # cp --version
GNU fileutils 3.9
root@cherimoya [2] # cp --help | grep recurs
-r copy recursively, non-directories as files
-R, --recursive copy directories recursively
root@cherimoya [3] #
The oldest version on the GNU ftp server is fileutils-3.13 [1]. I vaguely remember having some links to older versions, probably somewhere in my archived mail. But I don't remember if it was fileutils-3.9 or earlier.
I co-maintain GNU coreutils, so I am interested in reading them. If you have them, you can email me privately or on the public mailing list. Both are listed on the homepage [2].
[1] https://ftp.gnu.org/old-gnu/fileutils/ [2] https://www.gnu.org/software/coreutils/
You may also notice that some of these utilities will allocate memory, then never free it. They just let the OS handle that on program shutdown. That is also generally not recommended in arbitrary code. But again, it's fine for a one-and-done sort of program.
For these cases, the whole program is essentially one function call, and the global namespace is essentially the "body" of that function (hand waving a bit).
It's all a bit subjective, of course (:
Not sure why you wouldn't want to preserve timestamps, links, etc. by default.
It's also not even completely covering the weird case of -r and -R for the cp command. On HP-UX, for example, the twain were different, but not in the way that they were in old GNU Core Utilities. That would be too easy. (-:
The AIX manual for cp explains its difference between -r and -R:
* https://ibm.com/docs/en/aix/7.1.0?topic=c-cp-command
Illumos also treats the two differently, but in a subtly different way:
The "metadata is atomically copied" part would support very nicely the usual text editor's idiom of rename(2)ing a temporary file over the source after fully writing it out — you still need to accurately replicate the permissions and extended attributes. And just as shells are important enough programs to have fork(2) almost exactly suited for them, it would make sense to have copy(2), suited for the text editors.
However, I should note that possibly the first company to invent what you describe was Microsoft.
Novell Netware 386 had an NCOPY command which invoked a Netware extension to the DOS API that told the server to perform the entire copy on the server.
But even earlier, OS/2 1.x had a proper DosCopy() system call. Since it could be passed down to the installable filesystem drivers for intra-volume copies, something like the Netware client for OS/2 could in theory turn it into the same protocol call that did server-side copies. There was a NET COPY command in LAN Manager (and LAN Server, if memory serves) that did the same optimization.
Eh, when fork was invented, most (virtual) memory systems did not have the first clue about copy-on-write either. And honestly, it's really not that difficult to support — it's essentially hard links, just with slightly different semantics.
Linux has FICLONE [1], which I prefer because it operates on two file descriptors, allowing you to safely modify file metadata after the fact. macOS has clonefile, clonefileat, and fclonefileat [2]. Sadly, there is no way to operate on two file descriptors. The best you get is fclonefileat, which operates on a source file descriptor. Solaris has reflink and reflinkat, which operate on two paths, the latter relative to file descriptors [3]. In that case, one needs to be careful opening the destination to make changes to the metadata.
GNU coreutils has support for reflinks on Linux and macOS. But I've been thinking about adding support for Solaris as of late [4]. Sadly, I don't use it enough to test it as much as I would like.
Hopefully, a few years down the line the interfaces converge, and it is as simple as hard linking.
[1] https://man7.org/linux/man-pages/man2/FICLONE.2const.html [2] https://www.manpagez.com/man/2/clonefile/ [3] https://docs.oracle.com/cd/E86824_01/html/E54766/reflinkat-3... [4] https://lists.gnu.org/archive/html/coreutils/2026-09/msg0012...
I didn't even know -r was a thing until today.
https://unix.stackexchange.com/questions/82485/when-wouldnt-...
It seems that recursive by default would have been much more intuitive.
Yes, seriously. When you read about the supposed evils of cat -v from the Unix nostalgia people, remember that it was the same people who gave cat its -v option who also gave cp its -r option, in 4.2BSD.
It took over half a decade to percolate out of the BSD world, too. AT&T Unix System 5 did not have an -r option to cp. Here's Brandon S. Allbery explaining in 1987 how one copies directories on AT&T Unix System 5 Releases 2/3 by combining find and cpio -p:
* https://groups.google.com/g/comp.unix.questions/c/XiumTgkcYR...
Originally we read directories as raw byte streams and liked it, you know. (-:
Then the people who complained about cat -v went ahead and made better Unix, called Plan 9, in which moving (as opposed to merely renaming) a directory is impossible: instead, you're supposed to do mkdir && dircp && rm -r. Which is quite a choice, if I say so myself: there is simply no low-level primitive (syscall or 9p message) for moving files across directories, even on the same file server. Their version of mv can move files across the directories, but it's still done with internal equivalent of cp+rm.
Feels like this would be exactly the kind of thing they would get wrong. Fur exactly, the training set isn't trained to know the context of execution (FreeBSD vs macos vs Linux), right?
appearently i am not :') never knew there was -r
Is it the case in another country to have a localized name for that?
Bit curious what the pronunciation difference would've been in French.
On another note, looking at the Wikipedia article:
> When the franchise was released internationally, the short form of the title was used, with an acute accent (´) over the e to aid in pronunciation.
I'm realizing that didn't do anything for English since the syllable stressed in English is "Po".
It is common for brands to localize their names. E.g. Axe (the deodorant) in some countries is branded as Lynx.
tar -cf - . | (cd <dest>; tar -xf -)
(or ssh <target> prepended rather than sandwiched, to copy from remote)
user@host:/tmp$ cat rnd.file | sha256sum
71d3392be59210c517ab889fca715a46dee54f6326a9d901db0addd351607cb6 -
user@host:/tmp$ cat rnd.file | ssh user@otherhost sha256sum
71d3392be59210c517ab889fca715a46dee54f6326a9d901db0addd351607cb6 -
user@host:/tmp$ cat rnd.file | zstd -z | ssh user@otherhost "zstd -d | sha256sum"
71d3392be59210c517ab889fca715a46dee54f6326a9d901db0addd351607cb6 -
And the received wisdom about long options in the BSDs is a quarter of a century out of date. When the BSDs gained a getopt_long() in their C libraries thanks to Klausner and Baron, long options quietly started appearing. This process has been gradually and quietly on-going for the whole of the 21st century.
"NextBSD" was first released in 2015:
* https://en.wikipedia.org/wiki/NextBSD
Over a decade after macOS/Mac OS X was initially released:
> macOS (previously OS X and originally Mac OS X) is a proprietary Unix[7][8] operating system, derived from OPENSTEP for Mach and FreeBSD, which has been marketed and developed by Apple since 2001.
* https://en.wikipedia.org/wiki/MacOS
> Darwin is the core Unix-like operating system of macOS, iOS, watchOS, tvOS, iPadOS, audioOS, visionOS, and bridgeOS. It previously existed as an independent open-source operating system, first released by Apple in 2000. It is composed of code derived from NeXTSTEP, FreeBSD[3] and other BSD operating systems,[7] Mach, and […]
* https://en.wikipedia.org/wiki/Darwin_(operating_system)
I remember reading release notes for FreeBSD in the '00s and seeing the exact same lines in the release notes for earlier versions of OS X.
macOS isn't "Unix-like"; it's an Open Group certified UNIX™ [1].
[1]: https://www.opengroup.org/openbrand/register/brand3725.htm
https://www.reddit.com/r/freebsd/comments/1g07sdm/comment/lr...
Essentially, macOS was indeed based on NeXTSTEP originally, but over the years they copied quite a bit of BSD code over (mostly FreeBSD I think). I don't think the Unixy parts of the original NeXTSTEP survives much in modern macOS.
Also, I always have this vague fear that I'll rsync in the wrong direction, or accidentally blow away unrelated files in rsync's efforts to fully synchronize two directories (can't remember if this is a valid concern).
I'm sure these concerns would go away if I used it regularly, but I just don't. ‘cp' or ’scp’ almost always meet my needs.
Kinda like the way people are probably right that I should learn to use ’awk’, but I just can't muster the motivation.
https://github.com/RsyncProject/rsync/issues/119#issuecommen...
https://pubs.opengroup.org/onlinepubs/9799919799/utilities/c...
https://pubs.opengroup.org/onlinepubs/9799919799/utilities/
Edit: adjusted to the latest version of the standard.