On Wed, Jun 15, 2011 at 05:25:17PM +0200, Boudewijn Dijkstra wrote:
> Op Wed, 15 Jun 2011 16:52:12 +0200 schreef Jan Stary <[email protected]>:
> >The manpage of cp says
> >
> > -f For each existing destination pathname, remove it and
> >create a
> > new file, without prompting for confirmation, regardless of its
> > permissions. This option overrides any use of -i.
> >
> > -i Write a prompt to the standard error output before
> >copying a file
> > that would overwrite an existing file. If the response from the
> > standard input begins with the character `y', the file copy is
> > attempted.
> >
> >but that isnot what cp actually does:
> >
> >$ rm -f echo bar
> >$ echo new > foo
> >$ echo old > bar
> >$ cp -fi foo bar
> >overwrite bar? n
> >$ cat bar
> >old
> >
> >Accoording to the manpage, the '-f' should have overrided the '-i'.
> >Instead, it asked for confirmation, which said 'n', and cp(1) did
> >not copy foo over bar, as it still has the old content.
>
> Manpage has been like this forever. Looks like the behaviour has
> been bugged since 1999:
Comments below.
>
> --- src/bin/cp/cp.c 1998/07/03 17:43:56 1.12
> +++ src/bin/cp/cp.c 1999/05/06 18:19:45 1.13
> @@ -91,7 +91,7 @@ static char rcsid[] = "$OpenBSD: cp.c,v 1.12 1998/07/0
> PATH_T to = { to.p_path, "" };
>
> uid_t myuid;
> -int Rflag, iflag, pflag, rflag;
> +int Rflag, fflag, iflag, pflag, rflag;
> int myumask;
>
> enum op { FILE_TO_FILE, FILE_TO_DIR, DIR_TO_DNE };
> @@ -129,10 +129,12 @@ main(argc, argv)
> Rflag = 1;
> break;
> case 'f':
> + fflag = 1;
> iflag = 0;
> break;
> case 'i':
> iflag = isatty(fileno(stdin));
> + fflag = 0;
> break;
> case 'p':
> pflag = 1;
>
> So the behaviour depends on the order of the arguments. E.g. when doing:
> $ cp -if foo bar
> no confirmation is asked, and:
> $ cat bar
> new
> .
>
> Here's a fix (tested):
>
> --- src/bin/cp/cp.c.orig Sun Nov 4 03:01:57 2007
> +++ src/bin/cp/cp.c Wed Jun 15 17:20:25 2011
> @@ -113,8 +113,10 @@
> iflag = 0;
> break;
> case 'i':
> - iflag = isatty(STDIN_FILENO);
> - fflag = 0;
> + if (!fflag) {
> + iflag = isatty(STDIN_FILENO);
> + fflag = 0;
Redundant assignment
Posix does not say anything about the interaction of -i and -f. I
hesitate to change the behaviour. Maybe we should check against other
BSD's first.
-Otto
> + }
> break;
> case 'p':
> pflag = 1;
>
>
>
>
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