ping
On Sun, Sep 27, 2015 at 09:52:16AM -0500, Matthew Martin wrote:
> The following outputs only $ with a newline.
>
> { i=0; while [ $i -lt 89 ]; do printf $i\\0; : $(( i++ )); done; } |
> xargs -0 -I $ printf '%s\n' $
>
> The problem is two fold. The first is that strnsubst gives up on
> substituting since replstr is greater than maxsize. This should likely
> cause an error, but I don't know the preferred way to do that.
>
> The second problem is that count needs to be incremented so that the
> utility will be run after a null byte. The patch below comes from
> FreeBSD. https://svnweb.freebsd.org/base?view=revision&revision=142604
>
> That commit also moved a count++. While I don't believe that it is
> necessary; but it also doesn't hurt. I believe it makes the code easier
> to follow as now all paths immediately short circuit to addch except
> null and EOL.
>
>
> Index: xargs.c
> ===================================================================
> RCS file: /cvs/src/usr.bin/xargs/xargs.c,v
> retrieving revision 1.29
> diff -u -p -r1.29 xargs.c
> --- xargs.c 18 Apr 2015 18:28:38 -0000 1.29
> +++ xargs.c 27 Sep 2015 06:20:01 -0000
> @@ -255,11 +255,9 @@ parse_input(int argc, char *argv[])
> ch = getchar();
> if (isblank(ch)) {
> /* Quotes escape tabs and spaces. */
> - if (insingle || indouble)
> + if (insingle || indouble || zflag)
> goto addch;
> hasblank = 1;
> - if (zflag)
> - goto addch;
> goto arg2;
> }
>
> @@ -274,15 +272,22 @@ parse_input(int argc, char *argv[])
> }
> goto arg1;
> case '\0':
> - if (zflag)
> + if (zflag) {
> + /*
> + * Increment 'count', so that nulls will be treated
> + * as end-of-line, as well as end-of-argument. This
> + * is needed so -0 works properly with -I and -L.
> + */
> + count++;
> goto arg2;
> + }
> goto addch;
> case '\n':
> + if (zflag)
> + goto addch;
> hasblank = 1;
> if (hadblank == 0)
> count++;
> - if (zflag)
> - goto addch;
>
> /* Quotes do not escape newlines. */
> arg1: if (insingle || indouble)
