What is the correct find -exec syntax

Question

I wanted to delete files that were greater than 2MB within a specific folder. So I ran:

find . -size +2M

And I got a list of two files

./a/b/c/file1

./a/f/g/file2

So I then run:

find . -size +2M -exec rm ;

and I get the error message Find: missing argument to -exec

I check the syntax in the man page and it says -exec command ;

So instead I try

find . -size +2M -exec rm {} +

And it works. I understand that the {} make it execute the command like rm file1 file2 instead of rm file1; rm file2;.

So why didn't the first one work?

ANSWER:

I guess I just had to RTFM a couple of times to finally understand what it was saying. Even though the first example doesn't show {}, the braces are required in all cases. And then either add \; or + depending on the desired method. Don't just read the heading. Read the description as well. Got it.

Answer 1

You can use any of the forms:

find . -size +2M -exec rm {} +

find . -size +2M -exec rm {} \;

The semicolon should be escaped!

Answer 2

-exec rm {} \;

you can use.. man find

-exec command ;
              Execute command; true if 0 status is returned.  All following arguments to find are taken to be arguments to the  command  until
              an  argument  consisting of `;' is encountered.  The string `{}' is replaced by the current file name being processed everywhere
              it occurs in the arguments to the command, not just in arguments where it is alone, as in some versions of find.  Both of  these
              constructions  might  need  to  be escaped (with a `\') or quoted to protect them from expansion by the shell.  See the EXAMPLES
              section for examples of the use of the -exec option.  The specified command is run once for each matched file.  The  command  is
              executed  in  the  starting directory.   There are unavoidable security problems surrounding use of the -exec action; you should
              use the -execdir option instead.

       -exec command {} +
              This variant of the -exec action runs the specified command on the selected files, but the command line is  built  by  appending
              each  selected file name at the end; the total number of invocations of the command will be much less than the number of matched
              files.  The command line is built in much the same way that xargs builds its command  lines.   Only  one  instance  of  `{}'  is
              allowed within the command.  The command is executed in the starting directory.

Answer 3

For efficiency's sake, you're usually better off using xargs:

$ find /path/to/files -size +2M -print0 | xargs -0 rm

Answer 4

I'd not use -exec at all for this. find can also remove files itself:

find . -size +2M -delete

(this is probably a GNUism though, don't know if you'd find this in non-gnu find)

Answer 5

As documented, -exec requires {} as a placeholder for the output of find.

The definitive guide for using bash and GNU tools is here

As you can see, it explicitly shows the second command you used as an example.