// dirname.c, version 1.0.1
// OMKOV coreutils implementation of POSIX dirname
// Copyright (C) 2020, Jakob Wakeling
// MIT Licence

#include "util/error.h"
#include "util/optget.h"

#include <stdio.h>

#define VERSION "1.0.1"

static struct lop lops[] = {
	{ "help",    ARG_NUL, 256 },
	{ "version", ARG_NUL, 257 },
	{ NULL, 0, 0 }
};

static void hlp(void);
static void ver(void);

int main(int ac, char *av[]) { A0 = av[0];
	struct opt opt = OPTGET_INIT; opt.str = ""; opt.lops = lops;
	for (int o; (o = optget(&opt, av, 1)) != -1;) switch (o) {
	case 256: { hlp(); return 0; }
	case 257: { ver(); return 0; }
	default: { return 1; }
	}
	
	if (opt.ind == ac) { error(1, "missing operand"); }
	
	register char *p = av[opt.ind];
	
	for (; *p; ++p) {} for (--p; *p == '/'; --p);
	if (p + 1 == av[opt.ind]) { fputs("/\n", stdout); return 0; }
	
	for (; *p && *p != '/'; --p);
	if (p + 1 == av[opt.ind]) { fputs(".\n", stdout); return 0; }
	
	for (; *--p == '/';);
	if (p + 1 == av[opt.ind]) { fputs("/\n", stdout); return 0; }
	else { p[1] = 0; }
	
	fputs(av[opt.ind], stdout); fputc('\n', stdout);
	return 0;
}

static void hlp(void) {
	puts("dirname - return the directory portion of a path\n");
	puts("usage: dirname string\n");
	puts("options:");
	puts("  --help     Display help information");
	puts("  --version  Display version information");
}

static void ver(void) {
	puts("OMKOV coreutils dirname, version " VERSION);
	puts("Copyright (C) 2020, Jakob Wakeling");
	puts("MIT Licence (https://opensource.org/licenses/MIT)");
}