How to remove all items in a folder except for grepped items

Question

I would like to create a cleanup script for a directory used for backups.

For example: I have 10 files in a directory and they include numbering in the file name

such as:

b_100
b_101
b_102
b_103
b_104
b_105
b_106
b_107
b_108
b_109
b_110

I would like to grep for specific files within the directory from b_105 to b_110 and remove all the rest. Meaning b_100 b_101 b_102 b_103 b_104 will all be removed/deleted.

If I would to grep for one file within a directory like b_110 then remove everything not grepped for.

Answer 1

With zsh:

setopt extendedglob
rm -rf -- ^b_<105-110>

Would remove all non-hidden files and directories except those whose name starts with b_ and ends in a decimal number whose value is comprised in between 105 and 110.

If you only want to remove b_* files:

rm -rf -- b_(*~<105-110>)

~ being zsh glob operator for except.

Or you could do:

all_b_files=(b_*)
to_exclude=(b_{105..110})
rm -rf -- ${all_b_files:|to_exclude}

With ksh93 or bash -O extglob (or zsh -o kshglob):

set -- b_{105..110} # set positional parameters to b_105 b_106...
IFS='|'             # used for joining positional parameters in "$*"
pattern="$*"        # prepare extended ksh glob
IFS=                # empty IFS to prevent splitting
rm -rf -- !($pattern)

Answer 2

With bash and extended globbing enabled, you can do:

shopt -s extglob 
glob=$(echo b_{105..110} | sed 's/ /|/g')
rm -- !($glob)

That will first set the variable glob to the output of:

$ echo b_{105..110} | sed 's/ /|/g'
b_105|b_106|b_107|b_108|b_109|b_110

So, a list of the desired file names separated by a |. Then, the command rm -- !($glob) will remove all files not matching $glob.

Answer 3

You can use find to list all none matching files in a directory:

find /path/to/directory -not -name "file_name_to_keep" -type f

You can then pipe the output of find into xargs or just use find's built in exec or delete feature.

find /path/to/directory -not -name "file_name_to_keep" -type f -exec rm "{}" \;

or using GNU find's built in delete option

find /path/to/directory -not -name "file_name_to_keep" -type f -delete

More discussion of the various methods of deleting based on find output here: How to delete directories based on `find` output?

Answer 4

If you're grepping for a string within the file, you can use -L :

grep -L "string" ./* | xargs rm

Alternatively - as you said you were using this for backups, you could use find to find all files past a certain date old, and remove them with -exec. That would be a better solution than a grep if you are using date-5days for instance.

Answer 5

I didn't read the whole question, but when you say "except the grepped items", this immediately makes me think that you don't know the -v grep parameter, which means "Everything except ...", e.g.:

ls -ltra | grep -v .txt

This will show you a list of all files, except the text files.