options.c

// SPDX-License-Identifier: BSD-3-Clause
// Copyright (C) 2003-2014 Brian Harring <ferringb@gmail.com>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <diffball/defs.h>
#include "options.h"

void print_usage(const char *prog, const char *usage_portion, struct usage_options *text, int exit_code)
{

	struct usage_options *u_ptr;
	print_version(prog);
	u_ptr = text;
	unsigned int long_len = 0;
	while (1)
	{
		if (u_ptr->long_arg == NULL && u_ptr->description == NULL)
			break;
		if (u_ptr->long_arg != NULL)
		{
			long_len = MAX(strlen(u_ptr->long_arg), long_len);
		}
		u_ptr++;
	}
	long_len = MIN(15, long_len);
	fprintf(stdout, "	usage: %s [flags] ", prog);
	if (usage_portion)
		fprintf(stdout, "%s", usage_portion);
	fprintf(stdout, "\n\n");
	u_ptr = text;
	while (1)
	{
		if (u_ptr->long_arg == NULL && u_ptr->description == NULL)
			break;
		if (0 != u_ptr->short_arg)
		{
			fprintf(stdout, "  -%c ", u_ptr->short_arg);
			if (NULL != u_ptr->long_arg)
				fprintf(stdout, "--%-*s", long_len, u_ptr->long_arg);
			else
				fprintf(stdout, "  %*s", long_len, "");
			if (NULL != u_ptr->description)
				fprintf(stdout, " %s\n", u_ptr->description);
			else
				fprintf(stdout, "\n");
		}
		else if (NULL != u_ptr->long_arg)
		{
			fprintf(stdout, "     --%-*s", long_len, u_ptr->long_arg);
			if (NULL != u_ptr->description)
				fprintf(stdout, " %s\n", u_ptr->description);
			else
				fprintf(stdout, "\n");
		}
		else if (u_ptr->description != NULL)
		{
			// description fluff
			fprintf(stdout, "\n%s\n", u_ptr->description);
		}
		else
		{
			// all opts exhausted.  end of usage struct aparently (else someone screwed up)
			break;
		}
		u_ptr++;
	}
	fprintf(stdout, "\n");
	exit(exit_code);
}

void print_version(const char *prog)
{
	fprintf(stdout, "diffball version %s, program %s (C) 2003-2021 Brian Harring\n", VERSION, prog);
	fprintf(stdout, "https://github.com/ferringb/diffball\n");
	fprintf(stdout, "THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY! USE AT YOUR OWN RISK!\n");
	fprintf(stdout, "Report bugs to <ferringb@gmail.com>\n\n");
}

char *
get_next_arg(int argc, char **argv)
{
	if (argc > optind)
		return argv[optind++];
	return NULL;
}