There's lots of new stuff, and some old cruft has been dumped, so some programs may need a few updates, but there's still a high level of compatibility. The page above links to release notes with details of what's in and what's out.
It may be easier to reason about when thinking of the way $(mount -o loop) works with .iso files -- a file that is a container for other files that one can mount as if it were a filesystem
I was expecting pathlib in Python <https://docs.python.org/3/library/pathlib.html> to have one since a lot of Python distributions ship the standard library in .zip files but evidently not. Python gonna Python in that way
Firefox actually used to ship with that same "jar:" protocol handler, too, and I made good use of it for reading the javadoc html which was shipped inside zip files and was indescribably easier than trying to manage all the .html files in a Java 8 SDK distribution. They made heavy use of this because a lot of their internals were in .xpi formats (which is also a .zip file) but they recently dropped it because Firefox gonna Firefox^W double down on some random shit other than making a sane browser
It looks like https://github.com/cybernoid/archivemount provides a similar experience in the shell, although one would have to mount the file first.
> Consider the naive attempt to clean out the /tmp directory.
> cd /tmp
> foreach f [glob *] {file delete -force $f}
> A file ~ or ~user maliciously placed in /tmp will have rather unfortunate consequences.
i learned a few new habits since then. i almost never use rm -r and i avoid "*" as a glob by itself. instead i always try to qualify "*" with a path, remove files first: "rm dir/*"; and then remove the empty directory. "rmdir dir/"
if i do want to use rm -r, it is with a long path. eg in order remove stuff in the current directory i may distinctly add a path: rm -r ../currentdir/*" instead of "rm -r *"
related, i also usually run "rm -i", but most importantly, i disable any alias that makes "rm -i" the default, because in order to override the -i you need to use -f, but "rm -i -f" i NOT the same thing as "rm". rm has three levels of safety: "rm -i; rm; rm -f". if "rm -i" is the default the "rm" level gets disabled, because "rm -i -f" is the same as "rm -f"
It has a syntax of your expectations, functionally existing as a set of boundaries, and you can hook it to always run as a wrapper for some set of commands. It essentially stages the wrapped command and if none of the boundaries are violated it goes through. Otherwise it yells at you and you need to manually override it.
For instance, pretend I'm ok with mv being able to clobber except in some special directory, let's call it .bitcoin or whatever. (chattr can also solve this, it's just an example). The tool can be implemented relying on things like bpf or preload
Originally I wanted it as a SQL directive ... a way to safeguard a query against doing like `update table set field=value expect rows=1` where you meant to put in the where clause but instead blew away an entire column. I think this would be especially useful surfacing it in frameworks and ORMs some of which make these accidents a bit too easy.
I actually know postgres people. I should probably ask them
I was just reminded of a good idea I never implemented
But this is stupid. These are computers, we can make whatever we want. Executing a delete or update should, if one desires, not have to be database knifeplay.
I don't disagree that it's impossible, but how do you get the syntax standardized at this point? Do you get various dialects, or an agreement between vendors? Look how slowly the standard moves, when do we get this where it's usable in most popular RDBMS?
Just implement it for one and if it works, the others will add it
Here's a list of 1,000 postgres extensions, it's not a big deal: https://gist.github.com/joelonsql/e5aa27f8cc9bd22b8999b7de8a...
Things are way more modular than they used to be.
I can probably do it again and just try to get attention for it.
Or... "DRYRUN UPDATE ...", which is more like "EXPLAIN UPDATE..."
Thoughts?
I only mean this from a more ANSI SQL side of things, where you might want to build your skills up to use as much of the standard as possible, until it's no longer possible and make sense to dip into platform specifics. I used to build code around being cross-platform, but at the same time realized that it's more useful to learn the ANSI standard, and then break free with LOTS of useful comments where it makes sense to do things more efficiently and with safety that you don't get normally.
Bad:
rm *
rm ./*
rm /tmp/d/*
rm */deadmeat
rm d/*
rm -rf "$TSTDIR"/etc
I guess I'm not likely to type that into the shell, or if I do, I then tab-complete to expand it.
I could definitely see myself using that in a shell script, though. I tend to do validity checks there:
if ! [ -d "$TSTDIR" ]; echo "$TSTDIR not found, stupid" >&2; exit 1; fi
if [ -d "$TESTDIR" ]; then
rm -rf "$TSTDIR"/etc
fifor i in $(find something); do echo "rm -f $i"; done
(bash example as my TCL is rusty)
like the one from my colleague who once fat fingered fsck into mkfs and i lost my personal homepage because of it. what makes me uncomfortable about that story is that it was not my fault. if it were it would have been easier to tell. but at the time i was quite frustrated and my colleague felt that despite me trying to not get angry at him. i still feel really bad about my reaction then, adding to his predicament, since he had to live with the guilt about losing our website and everyone's personal home directory. it's bad when a mistake causes you to loose something personal, but so much worse when you loose someone elses stuff.
talking about mistakes is how we learn from them. the important part is not to get embarrassed about them. however that requires an environment where we are not blaming each other when something goes wrong.
i could have made that mistake myself. and i applied this lesson to my own learning as if i had.
blessed be the pessimist, for he hath made backups...
I try to tell as many of these stories in person as possible, to let everyone know that unless you have dealt with this kind of accident, you're either in the 1% or due for your turn. I'd like to think that sharing these stories might at least give someone some pause before they go ahead and throw caution to the wind.
You can use "\rm" to invoke the non-aliased version of the command. I made "rm -i" the default using an alias and occasionally use "\rm" to get the decreased safety level you described. I think it is more convenient that way.
I like it for two reasons. Find feels like it has more solidly defined patterns and recursion than shell globing and by leaving off the "-delete" it give me a chance to inspect the results before committing to my actions.
Edit: Just checked and find doesn’t by default.
besides that, the primary reason for deleting stuff is to gain space. moving things to trash doesn't help with that.
what i sometimes do though, when mass deleting, is to move stuff to be deleted into a new folder (usually called "del" or "delete"). then verify the contents of the folder before removing it.
what would be more useful is a kind of trash implementation that does not take space, in that it keeps files around but reports them as unused space that can be overwritten when space is needed. kind of like undelete is possible on some filesystems. so that gone is gone because i can't control when deleted space gets used up, but in a panic situation i can revert the most recent deletes.
Just symlink /h to /home. So ~user becomes /h/user, in places where ~ is not expanded for you.