Linux Mint

1875 readers

16 users here now

Linux Mint is a free Linux-based operating system designed for use on desktop and laptop computers.

Want to see the latest news from the blog? Set the Firefox homepage to:

linuxmint.com/start/

where is a current or past release. Here's an example using release 21.1 'Vera':

https://linuxmint.com/start/vera/

founded 3 years ago

MODERATORS

erpicht@lemmy.ml

Just started with linux mint, need help with a command (feddit.nl)

submitted 8 hours ago by skaarl@feddit.nl to c/linuxmint@lemmy.ml

19 comments fedilink hide all child comments

As the title says, I just started with linux mint and am falling in love with bash scripts 😍 Actually I'm not sure if it's considered a script, but I want to delete the last 2 files in all subfolders in a folder. So far I've (after great effort) got the terminal to list the files, but I want to delete them. Here is how I get them listed:

for f in *; do ls $f | tail -n 2; done

All their names come satisfyingly up in the terminal. Now what? I tried adding | xargs rm but that didn't delete them. I also tried something with find command but that didn't work either. Some folders have 3 items, so I want to delete #2 and 3. Some folders have 15 items so I want to delete #14 and 15. Folders are arranged by name, so it's always the last 2 that I want to delete.

It's frustrating to be sooooo clooooose, but also very fun. Any help is appreciated!

you are viewing a single comment's thread
view the rest of the comments

[–] harsh3466@lemmy.ml 1 points 2 hours ago* (last edited 2 hours ago) (1 children)

When you run the command without the xargs bit, like this:

for f in \*; do ls $f | tail -n 2; done\,

Does the output give you the full file path, or just the file names?

The full file path will look something like:

/dir1/dir2/actual-file

And of course the file name would just be:

some-file

If you're getting just the file name, that's the problem. Unless you're in the directory with the file you wish to delete, rm needs the full path.

Edit: grammar

[–] skaarl@feddit.nl 1 points 2 hours ago* (last edited 2 hours ago) (2 children)

Yea that must be it! It's spitting out just the file name and not the whole path. There is only 1 level of depth, so I want to remove

./folder1/file 3
./folder1/file4
./folder2/file11
./folder2/file12

so how do I get the whole path into xargs? I tried xargs "$f"/ but fortunately that didn't work because it was trying to delete all the directories lmao XD

[–] harsh3466@lemmy.ml 2 points 2 hours ago (1 children)

Here's the command to delete the files:

for f in *; do find ./"$f" -type f | sort | tail -n 2 | xargs -n 1 rm; done

If you want to insure it will target the correct files, first run this command (I HIGHLY recommend you do this first. Verify BEFORE you delete so you don't lose data):

for f in *; do find ./"$f" -type f | sort | tail -n 2; done

I'll be adding another comment reply with a breakdown of the command shortly (just need to write it up)

[–] harsh3466@lemmy.ml 3 points 1 hour ago* (last edited 1 hour ago) (1 children)

Here's what's happening in the command;

for f in *; do

You already know this for loop, which is using the * glob to iterate over each directory in the current directory.

find ./"$f" -type f

Instead of your original ls command, which gives the file names, and not their full paths, we're using GNU find, which outputs the full path of what it finds. The arguments are:

./"$f" - This tells find where to start its search. I double qouted the $f variable to properly expand the directory name even if it has nonstandard characters in it like spaces.

-type f - This tells find what kind of file object to look for. So it's two parts. -type to tell find there will be a specific type to look for, and the f flag, which means file. Meaning, it will only find files

The output of find is not sorted alaphabetically, so before piping the output to tail, we first pipe it to sort, which by default will sort alphanumerically, which we then pipe to tail to grab just the last two files, and finally we get to the xargs bit.

Here I added the -n 1 argument to xargs to get it to work on the files one at a time. This isn't actually necessary. You could just run it as xargs rm. I didn't realize that before I posted the command. (I'm still learning too! The learning never ends. :D )

[–] skaarl@feddit.nl 1 points 1 hour ago (1 children)

Thanks so much harsh!!! I will study this and hit Enter after I understand it.

Thanks again, that's epic.

[–] harsh3466@lemmy.ml 1 points 1 hour ago

You're welcome! Happy I could help.

One other quick note, do the filenames or directories have spaces in them? If they do, that will cause a problem with the command as it is and need some additional modification. I accounted for the possible spaces in the directory names with the find command, but not with xargs. I just realized that as I was looking it over again.