Comments on End Point Blog: Efficiency of find -exec vs. find | xargs

That's neat, Brian. I didn't know about th...

2010-09-14T12:40:24.647-04:00

That's neat, Brian. I didn't know about that.

It looks like it's an extension only available in the more recent GNU versions of find, but is nice to have.

You don't have to use xargs to get this behavi...

2010-09-14T12:18:32.533-04:00

You don't have to use xargs to get this behavious. Just use -exec command {} +. Note the plus sign instead of the semicolon.

From the man page:

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.

tante, good point about -delete, but note also tha...

2010-08-02T12:54:46.028-04:00

tante, good point about -delete, but note also that there are some pretty serious limitations (can't use -prune) and risks (can accidentally delete everything before other matches!) to using it. Quoting from the man page:

"Warnings: Don't forget that the find command line is evaluated as an expression, so putting -delete first will make find try to delete everything below the starting points you specified. When testing a find command line that you later intend to use with -delete, you should explicitly specify -depth in order to avoid later surprises. Because -delete implies -depth, you cannot usefully use -prune and -delete together."

Because of that, I find xargs a better option in most cases, but certainly I like -delete better than -exec rm.

Note that with xargs' -n option, you can for...

2010-07-29T09:19:27.810-04:00

Note that with xargs' -n option, you *can* force xargs to run once per file, if whatever you're passing the file names to can only handle one at a time. Of course, you could also use -exec for that. Another helpful argument is GNU xargs' --no-run-if-empty option (or the short version: -r). Surprisingly, by default xargs runs the command once even if there is no input.

One thing many people forget is that especially fo...

2010-07-29T07:45:06.161-04:00