Re: [PATCH] script: close file descriptors on exec

[Ruediger Meier <sweet_f_a@gmx.de>]

On Thursday 14 April 2016, Sami Kerola wrote:
> The commands spawned from script(1) will never need access various
> file descriptors the script(1) is using.
>
> Signed-off-by: Sami Kerola <kerolasa@iki.fi>
> ---
>  term-utils/script.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/term-utils/script.c b/term-utils/script.c
> index 1199742..88b522a 100644
> --- a/term-utils/script.c
> +++ b/term-utils/script.c
> @@ -419,15 +419,15 @@ static void do_io(struct script_control *ctl)
>  	};
>
>
> -	if ((ctl->typescriptfp = fopen(ctl->fname, ctl->append ? "a" :
> "w")) == NULL) { +	if ((ctl->typescriptfp = fopen(ctl->fname,
> ctl->append ? "ae" : "we")) == NULL) { warn(_("cannot open %s"),
> ctl->fname);
>  		fail(ctl);
>  	}
>  	if (ctl->timing) {
>  		if (!ctl->tname) {
> -			if (!(ctl->timingfp = fopen("/dev/stderr", "w")))
> +			if (!(ctl->timingfp = fopen("/dev/stderr", "we")))
>  				err(EXIT_FAILURE, _("cannot open %s"), "/dev/stderr");
> -		} else if (!(ctl->timingfp = fopen(ctl->tname, "w")))
> +		} else if (!(ctl->timingfp = fopen(ctl->tname, "we")))

"e" works for glibc only.

>  			err(EXIT_FAILURE, _("cannot open %s"), ctl->tname);
>  	}
>
> @@ -515,7 +515,7 @@ static void getslave(struct script_control *ctl)
>  {
>  #ifndef HAVE_LIBUTIL
>  	ctl->line[strlen("/dev/")] = 't';
> -	ctl->slave = open(ctl->line, O_RDWR);
> +	ctl->slave = open(ctl->line, O_RDWR | O_CLOEXEC);
>  	if (ctl->slave < 0) {
>  		warn(_("cannot open %s"), ctl->line);
>  		fail(ctl);
> @@ -625,7 +625,7 @@ static void getmaster(struct script_control *ctl)
>  			break;
>  		for (cp = "0123456789abcdef"; *cp; cp++) {
>  			*pty = *cp;
> -			ctl->master = open(ctl->line, O_RDWR);
> +			ctl->master = open(ctl->line, O_RDWR | O_CLOEXEC);
>  			if (ctl->master >= 0) {
>  				char *tp = &ctl->line[strlen("/dev/")];
>  				int ok;
> @@ -765,7 +765,7 @@ int main(int argc, char **argv)
>  	 * handled according to their default dispositions */
>  	sigprocmask(SIG_BLOCK, &ctl.sigset, &ctl.sigorg);
>
> -	if ((ctl.sigfd = signalfd(-1, &ctl.sigset, 0)) < 0)
> +	if ((ctl.sigfd = signalfd(-1, &ctl.sigset, SFD_CLOEXEC)) < 0)
>  		err(EXIT_FAILURE, _("cannot set signal handler"));
>
>  	DBG(SIGNAL, ul_debug("signal fd=%d", ctl.sigfd));