3 ms·

Can you send a write only file over the network? UNIX socket file? Device file? Setuid bit? What does setuid even mean when you push the file onto a Windows box

by chipsa 3y ago

Can you send a write only file over the network? UNIX socket file? Device file? Setuid bit? What does setuid even mean when you push the file onto a Windows box? Most people are only concerned with blob attachments when they say file.

crabbone 3y ago
> Can you send a write only file over the network? Yes. NFS can do that, for example. > UNIX socket file? I don't know a system off the top of my head that does this, but rsync could be possibly preserving file type given some flags. > Device file? Not immediately, but sort of. Eg. device files under /dev are created by udev based on the information it reads from a socket. In principle, you could have the user-space side of udev running on a machine other than the one physically attached to the block device thus exposed. Ultimately, however, you can do all of the above over the network if you use iSCSI, or have a driver (similar to Ceph, Lustre, BeeGFS etc.) that exposes filesystem over netwrok. Most importantly, however, I don't see how your question is relevant to anything I wrote. Suppose you couldn't do any of the things you naively thought you cannot do... then what? Why is sending something over the network is an indication of anything? > Most people are only concerned with blob attachments when they say file. So what? Most "people" (by which, I think, you mean "programmers") are irredeemably dumb. It doesn't matter what a majority of a group of idiots think. But even if they were smart, again, who cares what the majority of smart people thinks? -- majority isn't what establishes the truth.
- chipsa 3y ago
  You're stuck in the UNIX-ism of everything is a file. So things are files in Unix that in other operating systems are not. COM1 is a file in Windows. It doesn't make sense to transfer COM1 over the network. You can't store it. You can't send /dev/null over the network. You can send a representation of it via NFS, but anything you write to it via NFS isn't writing to the file, you're writing it back to the original server that you mapped NFS from. The representation of it isn't the file, just like a map isn't the terrain. If I map a filesystem over the network, I'm still not sending the file over the network. I'm just sending a hook for the server that's getting mapped to know what's going on. When I say most people, I mean most users. Most users aren't concerned with socket files, or write only files, or device files, because they aren't things they're concerned with. They think of a file as a blob of data, with maybe metadata for who can access it (et al). So, for the purposes of storing files, a file is a blob of data, not something being exposed across the network through special drivers.

by chipsa 3y ago

crabbone 3y ago

> Can you send a write only file over the network? Yes. NFS can do that, for example. > UNIX socket file? I don't know a system off the top of my head that does this, but rsync could be possibly preserving file type given some flags. > Device file? Not immediately, but sort of. Eg. device files under /dev are created by udev based on the information it reads from a socket. In principle, you could have the user-space side of udev running on a machine other than the one physically attached to the block device thus exposed. Ultimately, however, you can do all of the above over the network if you use iSCSI, or have a driver (similar to Ceph, Lustre, BeeGFS etc.) that exposes filesystem over netwrok. Most importantly, however, I don't see how your question is relevant to anything I wrote. Suppose you couldn't do any of the things you naively thought you cannot do... then what? Why is sending something over the network is an indication of anything? > Most people are only concerned with blob attachments when they say file. So what? Most "people" (by which, I think, you mean "programmers") are irredeemably dumb. It doesn't matter what a majority of a group of idiots think. But even if they were smart, again, who cares what the majority of smart people thinks? -- majority isn't what establishes the truth.

chipsa 3y ago
You're stuck in the UNIX-ism of everything is a file. So things are files in Unix that in other operating systems are not. COM1 is a file in Windows. It doesn't make sense to transfer COM1 over the network. You can't store it. You can't send /dev/null over the network. You can send a representation of it via NFS, but anything you write to it via NFS isn't writing to the file, you're writing it back to the original server that you mapped NFS from. The representation of it isn't the file, just like a map isn't the terrain. If I map a filesystem over the network, I'm still not sending the file over the network. I'm just sending a hook for the server that's getting mapped to know what's going on. When I say most people, I mean most users. Most users aren't concerned with socket files, or write only files, or device files, because they aren't things they're concerned with. They think of a file as a blob of data, with maybe metadata for who can access it (et al). So, for the purposes of storing files, a file is a blob of data, not something being exposed across the network through special drivers.