On Mon, Sep 13, 2010 at 02:49:58PM +0200, Joachim Schipper wrote:
>
> Here are two diffs to find(1).
>
> The first diff changes the last example in find(1). This diff:
> - makes it clear that it, in fact, works on all files *under* (not just
> "in") the current working directory;
that seems clearer, yes.
> - adds handling of *.gif files to illustrate ordering;
but we already have an example that does this:
Print out a list of all the files which are not both newer than
``ttt'' and owned by ``wnj'':
$ find / \! \( -newer ttt -user wnj \)
i think that covers it well enough.
> - changes to -print0 | xargs -0r to illustrate proper form.
>
wouldn;t it be better to just use "find -X"? it is shorter, and the
description of -X is probably the best place to start reading for most
people.
> The second diff is relative to the first diff, and adds the following
> warning to CAVEATS:
> "Using find in combination with xargs(1) requires some care:
>
> $ find . -name \e*.jpg | xargs rm
>
> would, given a file *important\n.jpg* (where *\n* is a newline),
> remove *important*. Use the -print0 or -X flags, or use -exec
> instead."
>
> This is already addressed in the man page (e.g. under the description of
> -print0 or -X), but many people (including the EXAMPLES) get it wrong;
> hopefully the above warning (and the references from the description of
> -print and the EXAMPLES section) prevents some people from making this
> mistake.
>
i don;t instinctively like this. if we document something correctly, we
shouldn;t be adding in duplicate text just in case it gets missed. there
is enough reading to do already, and what if the second text section is
also ignored/not understood by the reader?
i'd prefer to just concentrate on saying something well, once.
jmc
> Joachim
>
> Index: find.1
> ===================================================================
> RCS file: /cvs/src/usr.bin/find/find.1,v
> retrieving revision 1.78
> diff -u -p -r1.78 find.1
> --- find.1 15 Jul 2010 20:51:38 -0000 1.78
> +++ find.1 13 Sep 2010 12:29:56 -0000
> @@ -525,11 +525,11 @@ ending in a dot and single digit, but sk
> .Pp
> .Dl "$ find /usr/src -path /usr/src/gnu -prune -or -name \e*.[0-9]"
> .Pp
> -Find and remove all *.jpg files in the current working directory:
> +Find and remove all *.jpg or *.gif files under the current working directory:
> .Pp
> -.Dl "$ find . -name \e*.jpg -exec rm {} \e;"
> +.Dl "$ find . \e( -name \e*.jpg -o -name \e*.gif \e) -exec rm {} \e;
> or
> -.Dl "$ find . -name \e*.jpg | xargs rm"
> +.Dl "$ find . \e( -name \e*.jpg -o -name \e*.gif \e) -print0 | xargs -0r rm"
> .Sh SEE ALSO
> .Xr chflags 1 ,
> .Xr chmod 1 ,
>
> --- find.1 Mon Sep 13 14:12:53 2010
> +++ find.1.new Mon Sep 13 14:32:38 2010
> @@ -382,7 +382,10 @@
> It prints the pathname of the current file to standard output, followed
> by a newline
> .Pq Ql \en
> -character.
> +character. This should not be used in conjunction with
> +.Xr xargs 1 ,
> +see
> +.Sx CAVEATS .
> .It Ic -print0
> This primary always evaluates to true.
> It prints the pathname of the current file to standard output, followed
> @@ -530,6 +533,13 @@
> .Dl "$ find . \e( -name \e*.jpg -o -name \e*.gif \e) -exec rm {} \e;
> or
> .Dl "$ find . \e( -name \e*.jpg -o -name \e*.gif \e) -print0 | xargs -0r rm"
> +.Pp
> +Note the use of
> +.Ic -exec
> +or
> +.Ic -print0 ;
> +see
> +.Sx CAVEATS .
> .Sh SEE ALSO
> .Xr chflags 1 ,
> .Xr chmod 1 ,
> @@ -637,6 +647,26 @@
> and
> .Ql \&;
> may have to be escaped from the shell.
> +.Pp
> +Using
> +.Nm
> +in combination with
> +.Xr xargs 1
> +requires some care:
> +.Pp
> +.Dl "$ find . -name \e*.jpg | xargs rm"
> +.Pp
> +would, given a file
> +.Pa important\en.jpg
> +(where \en is a newline), remove
> +.Pa important .
> +Use the
> +.Ic -print0
> +or
> +.Ic -X
> +flags, or use
> +.Ic -exec
> +instead.
> .Pp
> As there is no delimiter separating options and file names or file
> names and the
