[PATCH v2] Implement argument parsing via argp.h.

[Thadeu Lima de Souza Cascardo]

On Sat, Mar 15, 2014 at 04:28:39PM -0300, Sergio Durigan Junior wrote:
> This commit implements argument parsing from the command line via
> argp.h. So far, I have added only one parameter ('-d', or
> '--declaracao') which is used for providing the filename of the
> declaration.  I have also marked this argument as optional, so that the
> user will still be able to provide the filename without using '-d'.
> 
> As an auxiliary support, I enabled the generation of the config.h header
> file, so that the program can obtain the package version and the bug
> report address directly from configure.ac.

Aplicado. Só fiz um commit separado para a mudança do endereço de bug
report.

Obrigado.
Cascardo.

> ---
>  .gitignore   |   1 +
>  bootstrap.sh |   1 +
>  configure.ac |   3 +-
>  rnetclient.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++--------
>  4 files changed, 93 insertions(+), 14 deletions(-)
> 
> diff --git a/.gitignore b/.gitignore
> index c037aae..c62646f 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -8,6 +8,7 @@ build-aux
>  config.log
>  config.status
>  configure
> +config.h*
>  
>  # Object files
>  *.o
> diff --git a/bootstrap.sh b/bootstrap.sh
> index 41e9823..1bf9968 100755
> --- a/bootstrap.sh
> +++ b/bootstrap.sh
> @@ -10,5 +10,6 @@ AUX_DIR=build-aux
>  test -d $AUX_DIR || mkdir -p $AUX_DIR
>  
>  aclocal
> +autoheader
>  autoconf
>  automake --add-missing --copy --force --foreign
> diff --git a/configure.ac b/configure.ac
> index c7a85dc..32090d2 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1,4 +1,4 @@
> -AC_INIT(rnetclient,2014.0,cascardo en minaslivre.org)
> +AC_INIT(rnetclient,2014.0,softwares-impostos en fsfla.org)
>  AC_CONFIG_AUX_DIR(build-aux)
>  AM_INIT_AUTOMAKE(AC_PACKAGE_NAME,AC_PACKAGE_VERSION)
>  AC_PROG_CC
> @@ -7,4 +7,5 @@ PKG_CHECK_MODULES(GNUTLS, gnutls >= 1.4.0, , AC_MSG_ERROR(Could not find gnutls)
>  AM_PATH_LIBGCRYPT(,,AC_MSG_ERROR(Could not find gcrypt))
>  LIBS="$LIBGCRYPT_LIBS $GNUTLS_LIBS $LIBS -lz"
>  CFLAGS="$LIBGCRYPT_CFLAGS $GNUTLS_CFLAGS $CFLAGS"
> +AC_CONFIG_HEADERS([config.h])
>  AC_OUTPUT(Makefile)
> diff --git a/rnetclient.c b/rnetclient.c
> index d264c72..6e126ca 100644
> --- a/rnetclient.c
> +++ b/rnetclient.c
> @@ -27,10 +27,81 @@
>  #include <netdb.h>
>  #include <gnutls/gnutls.h>
>  #include <zlib.h>
> +#include <argp.h>
> +#include "config.h"
>  #include "decfile.h"
>  #include "rnet_message.h"
>  #include "rnet_encode.h"
>  
> +/* Program version and bug report address.  */
> +
> +const char *argp_program_version = PACKAGE_VERSION;
> +const char *argp_program_bug_address = PACKAGE_BUGREPORT;
> +
> +/* Documentation strings.  */
> +
> +static const char rnetclient_doc[] =
> +	"Send the Brazilian Income Tax Report to the Brazilian "
> +	"Tax Authority";
> +static const char rnetclient_args_doc[] =
> +	"[-d|--declaration] FILE";
> +
> +/* Description and definition of each option accepted by the program.  */
> +
> +static const struct argp_option rnetclient_options_desc[] = {
> +	{ "declaration", 'd', "FILE", OPTION_ARG_OPTIONAL,
> +	  "The Income Tax Report file that will be sent.",
> +	  0 },
> +
> +	{ NULL },
> +};
> +
> +struct rnetclient_args {
> +	/* File representing the declaration.  */
> +	char *input_file;
> +};
> +
> +/* Parser for command line arguments.  */
> +
> +static error_t rnetclient_parse_opt(int key, char *arg, struct argp_state *state)
> +{
> +	struct rnetclient_args *a = state->input;
> +	switch (key) {
> +	case 'd':
> +		/* The user has explicitly provided a filename through
> +		   the '-d' switch.  */
> +		a->input_file = arg;
> +		break;
> +
> +	case ARGP_KEY_ARG:
> +		/* The user has possibly provided a filename without
> +		   using any switches (e.g., by running './rnetclient
> +		   file').  */
> +		a->input_file = arg;
> +		break;
> +
> +	case ARGP_KEY_END:
> +		/* We have reached the end of the argument parsing.
> +		   Let's check if the user has provided a filename.  */
> +		if (a->input_file == NULL)
> +			argp_error(state,
> +				   "You need to provide the Income Tax Declaration "
> +				   "filename.");
> +	}
> +
> +	return 0;
> +}
> +
> +/* Control struct used by argp.  */
> +
> +static struct argp rnetclient_argp = {
> +	rnetclient_options_desc,
> +	rnetclient_parse_opt,
> +	rnetclient_args_doc,
> +	rnetclient_doc,
> +	NULL, NULL, NULL
> +};
> +
>  static size_t chars2len (unsigned char buf[2]) {
>  	return (buf[0] << 8 | buf[1]);
>  }
> @@ -172,12 +243,6 @@ static int handshake(int c)
>  	return 0;
>  }
>  
> -static void usage(void)
> -{
> -	fprintf(stderr, "rnetclient [filename]\n");
> -	exit(1);
> -}
> -
>  static int rnet_send(gnutls_session_t session, char *buffer, size_t len, int header)
>  {
>  	int r = 0;
> @@ -329,17 +394,28 @@ int main(int argc, char **argv)
>  	int r;
>  	struct rnet_decfile *decfile;
>  	struct rnet_message *message = NULL;
> +	struct rnetclient_args rnet_args;
>  	gnutls_session_t session;
>  	int finish = 0;
>  	char *cpf;
> -	
> -	if (argc < 2) {
> -		usage();
> -	}
> -
> -	decfile = rnet_decfile_open(argv[1]);
> +	error_t err;
> +
> +	/* Parsing the command line arguments.  The argp_parse
> +	   function calls exit() if there is some error during the
> +	   parsing process (e.g., the user has provided an unknown
> +	   flag or the parsing function has called argp_error).
> +	   However, if our internal parsing function returns something
> +	   different than zero, then argp_parse returns this value to
> +	   us.  This is a bug, and should not happen in the current
> +	   state.  */
> +	memset(&rnet_args, 0, sizeof (rnet_args));
> +	err = argp_parse (&rnetclient_argp, argc, argv, 0, NULL, &rnet_args);
> +	if (err != 0)
> +		fprintf(stderr, "internal error while parsing command line arguments.");
> +
> +	decfile = rnet_decfile_open(rnet_args.input_file);
>  	if (!decfile) {
> -		fprintf(stderr, "could not parse %s: %s\n", argv[1], strerror(errno));
> +		fprintf(stderr, "could not parse file \"%s\": %s\n", rnet_args.input_file, strerror(errno));
>  		exit(1);
>  	}
>  
> -- 
> 1.8.1.4