Re: [PATCH 1/1] iptables: Add file output option to iptables-save

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Fri, May 26, 2017 at 12:25:16PM +0000, Oliver Ford wrote:
> Adds an option to output the results of iptables-save,
> ip6tables-save, and xtables-save save to a file.
> Updates the man page with this new option.
> 
> Uses the dup2 call to replace stdout with the specified file.
> Error output is unchanged.
> 
> This is a feature requested by a Gentoo developer in
> Bugzilla #905.

Applied, thanks.

One minor glitch here.

> @@ -159,6 +162,21 @@ int ip6tables_save_main(int argc, char *argv[])
>  		case 'M':
>  			xtables_modprobe_program = optarg;
>  			break;
> +		case 'f':
> +			file = fopen(optarg, "w");
> +			if (file == NULL) {
> +				fprintf(stderr, "Failed to open file, error: %s\n",
> +					strerror(errno));
> +				exit(1);
> +			}
> +			int ret = dup2(fileno(file), STDOUT_FILENO);

We prefer not to have variable declarations in the body. So I slightly
mangled your patch. See patch in the git repo for final version.

Thanks.