coreutils

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

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

#include <unistd.h>

#include <stdio.h>
#include <stdlib.h>

#define VERSION "1.0.1"

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

static int mode = 0;

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

int main(int ac, char *av[]) { (void)ac; A0 = av[0];
	struct opt opt = OPTGET_INIT; opt.str = "LP"; opt.lops = lops;
	for (int o; (o = optget(&opt, av, 1)) != -1;) switch (o) {
	case 'L': { mode = 0; break; }
	case 'P': { mode = 1; break; }
	case 256: { hlp(); return 0; }
	case 257: { ver(); return 0; }
	default: { return 1; }
	}
	
pwd:;
	char *cwd = mode ? getcwd(NULL, 0) : getenv("PWD");
	if (!cwd && !mode) { mode = 1; goto pwd; }
	else if (!cwd) { error(1, "%s", av[0]); }
	
	fputs(cwd, stdout); fputc('\n', stdout);
	
	if (mode) { free(cwd); } return 0;
}

static void hlp(void) {
	puts("pwd - print working directory name\n");
	puts("usage: pwd [-L|-P]\n");
	puts("options:");
	puts("  -L         Display the logical current working directory");
	puts("  -P         Display the physical current working directory");
	puts("  --help     Display help information");
	puts("  --version  Display version information");
}

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