Very Computer

Not knowing where else to ask about this tool, here goes:

How is the -prune action supposed to work?  The man page
indicates that it should inhibit recursion of a selected
portion of the directory tree.  (Refers to "current directory"...)

I get the impression that I could search the file system for
a file name, but exclude looking into certain directories...
but how?

If I do a "find / -name usr -prune", it won't recurse the
/usr tree, but then, it won't find anything except files
named usr any place else.  Not too useful, that form.

--
Dave Brown   Austin, TX

find / -name usr -prune -print

What you don't realize (though it is mentioned in the man page, it is easily
overlooked) is that simple juxtaposition of find actions is equivalent to an
AND operator. So that command means: start from /, look for something named
usr AND don't recurse into it AND print it.

What you want is an OR.

find / -name usr -prune -o -print

which means: start from /, look for something named usr and don't recurse
into it, otherwise print whatever it is you've found.

  Dave> Not knowing where else to ask about this tool, here goes: How
  Dave> is the -prune action supposed to work?  The man page indicates
  Dave> that it should inhibit recursion of a selected portion of the
  Dave> directory tree.  (Refers to "current directory"...)

  Dave> I get the impression that I could search the file system for a
  Dave> file name, but exclude looking into certain directories...
  Dave> but how?

  Dave> If I do a "find / -name usr -prune", it won't recurse the /usr
  Dave> tree, but then, it won't find anything except files named usr
  Dave> any place else.  Not too useful, that form.

Use either

 find / \( -name  usr -prune \) -o -print
or, better
 find / \( -path /usr -prune \) -o -print

: Not knowing where else to ask about this tool, here goes:

: How is the -prune action supposed to work?  The man page
: indicates that it should inhibit recursion of a selected
: portion of the directory tree.  (Refers to "current directory"...)

: I get the impression that I could search the file system for
: a file name, but exclude looking into certain directories...
: but how?

: If I do a "find / -name usr -prune", it won't recurse the
: /usr tree, but then, it won't find anything except files
: named usr any place else.  Not too useful, that form.

: --
: Dave Brown   Austin, TX

Try
   find / -path /usr -prune -o -print
which is shortcut for
   find / -path /usr -and -prune -or -print
The expression is interpreted using the normal rules of logical OR (-or)
and AND (-and).  AND is evaluated first.

If find comes across /usr, then "-path /usr" is true; and "-prune" will
skip the path, returning also true.  Since "-path /usr -prune" is true,
find will skip to a new path.  However, if find comes across something
other than /usr, then "-path /usr" is false; and "-prune" need not be
tested or acted upon.  Since "-path /usr -prune" is false, "-print" is
evaluated, returning always true and printing the path.

Now, if you want to search for a file name, then try
   find / -path /usr -prune -o -name filename -print

--