/*-----------------------------------------------------
 Implementation of Opts
 for command line options

 Generated by aargh 1.1.3
 Sun Feb 12 10:05:58 2006
-----------------------------------------------------*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <unistd.h>

#include "opts.h"

static void initialize( Opts * pOpts )
{
	pOpts->new_argc = 0;
	pOpts->new_argv = NULL;

	pOpts->infile_found = 0;
	pOpts->infile = NULL;
	pOpts->counter_found = 0;
	pOpts->counter = 0;
	pOpts->verbose = 0;
}

int get_Opts( int argc, char * argv[], Opts * pOpts )
{
	int rc = 0; /* return code */
	unsigned long counter_value = 0;
	char * tail = NULL;
	int opt;

	/* Define valid option characters */

	const char optstring[] = ":f:n:v";

	/* Initialize members of struct */

	initialize( pOpts );

	/* Suppress error messages from getopt() */

	opterr = 0;

	/* Examine command line options */

	while( ( opt = getopt( argc, argv, optstring ) ) != -1 )
	{
		switch( opt )
		{
			case 'f' :   /* Get infile */
				if( pOpts->infile_found )
				{
					fprintf( stderr, "Only one occurrence of -f option allowed\n" );
					rc = 1;
					break;
				}
				pOpts->infile_found = 1;

				pOpts->infile = optarg;
				break;
			case 'n' :   /* Get counter */
				if( pOpts->counter_found )
				{
					fprintf( stderr, "Only one occurrence of -n option allowed\n" );
					rc = 1;
					break;
				}
				pOpts->counter_found = 1;

				/* Skip white space; check for negative */

				while( isspace( (unsigned char) *optarg ) )
					++optarg;

				if( '-' == *optarg )
				{
					fprintf( stderr, "Negative argument not allowed for "
						"-n option: \"%s\"\n", optarg );
					rc = 1;
					break;
				}

				/* Convert to numeric value */

				errno = 0;
				counter_value = strtoul( optarg, &tail, 10 );
				if( *tail != '\0' )
				{
					fprintf( stderr, "Invalid or non-numeric argument "
						"to -n option: \"%s\"\n", optarg );
					rc = 1;
					break;
				}
				else if( errno != 0 )
				{
					fprintf( stderr, "Too large argument "
						"to -n option: \"%s\"\n", optarg );
					rc = 1;
					break;
				}

				pOpts->counter = counter_value;

				break;
			case 'v' :   /* Get verbose */
				pOpts->verbose = 1;
				break;
			case ':' : /* Missing argument */
				fprintf( stderr, "Required argument missing on -%c option\n",
					(char) optopt );
				rc = 1;
				break;
			case '?' : /* Invalid option */
				fprintf( stderr, "Invalid option '-%c' on command line\n",
					(char) optopt );
				rc = 1;
				break;
			default :  /* Programmer error */
				fprintf( stderr, "Internal error: unexpected value '-%c'"
					"for optopt", (char) optopt );
				rc = 1;
				break;
		} /* end switch */
	} /* end while */

	if( optind > argc )
	{
		/* This should never happen! */

		fprintf( stderr, "Program error: found more arguments than expected\n" );
		rc = 1;
	}
	else
	{
		/* Calculate new_argcv and new_argc to reflect */
		/* the number of arguments consumed */

		pOpts->new_argc = argc - optind + 1;
		pOpts->new_argv = argv + optind - 1;
	}

	return rc;
}