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From: chris@mcc.pyrsyd.oz (Chris Robertson)
Newsgroups: comp.unix.questions
Subject: Re: Recursion without -R
Keywords: recursion
Message-ID: <1990Aug22.042609.2006@mcc.pyrsyd.oz>
Date: 22 Aug 90 04:26:09 GMT
References: <494@llnl.LLNL.GOV> <13595@ulysses.att.com> <316@dynasys.UUCP>
Reply-To: chris@mcc.UUCP (Chris Robertson)
Organization: MCC Software Group
Lines: 38

In article <316@dynasys.UUCP> jessea@dynasys.UUCP () writes:
>In article <13595@ulysses.att.com>, swfc@ulysses.att.com (Shu-Wie F Chen) wrote the following:
>>In article <494@llnl.LLNL.GOV>, rjshaw@ramius.ocf.llnl.gov (Robert Shaw)
>>writes:
>>|>What are some quick tricks for getting programs like chmod and chown to
>>|>descend into all subdirectories? Programs without a -R option, that is.
>>find . -print | xargs chown foo
>>Of course, this only works if you have xargs, which is from System V and
>>is also available on SunOS in their System V software installation option.
>
>Why not just use "find . -exec chown foo {} \;"
>Or if you have to do many different commands, use:
>
>for x in `find . -print`
>do
>	chown foo $x
>	chgrp foobar $x
>	chmod 644 $x
>done
>
>This can be done from the command line and saves some time.

Using "xargs" is generally faster than using "-exec" with "find",
since "xargs" will stuff as many arguments as possible into a
single invocation of the program.  Thus you might have several
hundred separate invocations of "chown" and "chmod" with a "-exec",
as opposed to 10 or 15 with "xargs".  Since "find" is doing a
fork-and-exec for each "-exec" invocation, the time difference
can be noticeable on a big directory tree.

Incidentally, the "for" loop above could fail on a big directory tree,
as the length of the argument list could be too much for the shell
to handle.  If the loop is put into a script, however, and run as
"find . -print | xargs myscript", the problem goes away.

-- 
"Down in the dumps?  I TOLD you you'd     |    Chris Robertson
 need two sets..."                        |  chris@mcc.oz