how to delete number of files

packets · 02-09-2015, 12:54 PM

I'm trying to figure out if find could do this. I have a folder with 1000 files. I want to delete 150 files on that folder regardless of timestamp and filename. Is there a tool, command or option on find that could do this, please let me know.

Combining mtime or ctime to find is not advisable since it will not count the files or even if there are matches, I would still need to sum up the files until I reach 150 files.

Any suggestions?

suicidaleggroll · 02-09-2015, 01:04 PM

What do you mean "regardless of timestamp and filename"? Which files do you want to remove? How is the script supposed to decide which 150 need to be deleted?

Is it alright if it's sorted by name or size or date or something, or do they HAVE to be 100% random?

packets · 02-09-2015, 01:14 PM

Quote:

Is it alright if it's sorted by name or size or date or something, or do they HAVE to be 100% random?

If it could 100% random, that would be great but if there is no tool for that then lets sort by name e.g. A-Z,a-z.

Quote:

What do you mean "regardless of timestamp and filename"?

each files has their own unique filename and there is no pattern.

TIA

Miati · 02-09-2015, 01:30 PM

I'd like to know what you've tried
But here's some hints, sort has some options to randomize lists of information, head or tail can be set to limit output (perhaps to 150) and while loops can read lines of text from output of commands.
For example:

Code:

while read i; do echo "$i"; done <<< $(command)

See man pages for sort and head or tail.

I don't know if find can delete a random list of exactly 150 though.
However, combining the above makes it pretty easy.

suicidaleggroll · 02-09-2015, 01:35 PM

If you don't care which files are deleted, then you can just pipe the output of ls or find to head/tail to trim it to 150 and then pass it on to rm, eg:

Code:

find . | head -n 150 | xargs rm

Of course this will be susceptible to files with "bad" characters in the names (spaces, etc.). Usually you would use -print0 and -0 in xargs to get around that, but then you can't use head/tail. This post has some information on getting around that:
http://superuser.com/questions/39711...-option-print0

packets · 02-09-2015, 06:52 PM

Thanks guys! Why I don't think of using head. I haven't tried it yet but I'm expecting this will work.

metaschima · 02-09-2015, 06:58 PM

A slight modification for randomness and better file name handling:

Code:

find -type f -print0 | shuf -z -n 150 | xargs -0 rm -f

Keith Hedger · 02-09-2015, 07:01 PM

Quote:

Originally Posted by suicidaleggroll

If you don't care which files are deleted, then you can just pipe the output of ls or find to head/tail to trim it to 150 and then pass it on to rm, eg:

Code:

find . | head -n 150 | xargs rm

Of course this will be susceptible to files with "bad" characters in the names (spaces, etc.). Usually you would use -print0 and -0 in xargs to get around that, but then you can't use head/tail. This post has some information on getting around that:
http://superuser.com/questions/39711...-option-print0

Small problem with that is find would also include folders etc which would count towards the 150 but would not be removed by the rm command

Miati · 02-09-2015, 07:46 PM

Quote:

Originally Posted by Keith Hedger

Small problem with that is find would also include folders etc which would count towards the 150 but would not be removed by the rm command

Not hard to get around

Code:

find . -type f | head -n 150 | xargs rm