[SOLVED] find /common -name lost+found -prune -or -name fileTofind -print

kaz2100 · 11-02-2012, 03:10 AM

Hya,

Question
Why do these two commands return different result?

Code:

>find /common -name lost+found -prune -or -name fileToFind
/common/lost+found
/common/fileTofind
>

and

Code:

>find /common -name lost+found -prune -or -name fileToFind -print
/common/fileTofind
>

man page reads (man find)

Quote:

If the expression contains no actions other than -prune, -print is performed on all files for which the expression is true.

My system
Debian wheezy, AMD64 current. Version of find is 4.4.2. The directory /common is nfs mounted. Filesystem is EXT3.

My guess
My guess, (obviously incorrect) was that "-print" would be performed regardless of its existance at the end of command line. (commands after -or)

Closing remark
Thank you for your reading my post. Have a nice day!

cheers

SecretCode · 11-03-2012, 09:24 AM

I see the same results.

Here's what I think is going on:

Code:

find /common -name lost+found -prune -or -name fileToFind

is parsed as (with implicit print included):

Code:

find /common ( ( -name lost+found -prune ) -or ( -name fileToFind ) ) -print

But

Code:

find /common -name lost+found -prune -or -name fileToFind -print

is parsed as

Code:

find /common ( ( -name lost+found -prune ) -or ( -name fileToFind -print ) )

-prune returns true, but in the second syntax the -print action doesn't see it.

See the section in man find ending

Code:

                                         The expression on the right hand side of the -o is in parentheses only for clarity.  It
       emphasises that the -print0 action takes place only for things that didn't have -prune  applied  to  them.   Because  the
       default `and' condition between tests binds more tightly than -o, this is the default anyway, but the parentheses help to
       show what is going on.

kaz2100 · 11-05-2012, 04:36 AM

My bad!

After reading the post #2, I am depressed!!