utils-std

mknod.c (3188B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
#define _XOPEN_SOURCE 700 // mknod is in XSI
#include "../lib/mode.h"
#include <assert.h>
#include <errno.h>
#include <stdio.h>         // fprintf
#include <stdlib.h>        // abort, exit
#include <string.h>        // strerror, strrchr
#include <sys/stat.h>      // mknod
#include <sys/sysmacros.h> // makedev
#include <unistd.h>        // getopt
mode_t filemask;
static void
usage(void)
{
	fprintf(stderr, "Usage: mknod [-m mode] file <b|c|u|p> [major minor]\n");
}
static unsigned int
strtodev(char *arg)
{
	char *endptr = NULL;
	assert(errno == 0);
	long dev = strtol(arg, &endptr, 0);
	if(errno != 0)
	{
		fprintf(stderr, "mknod: error: Failed parsing '%s' into a number: %s\n", arg, strerror(errno));
		exit(1);
	}
	if(endptr != NULL && endptr[0] != 0)
	{
		fprintf(stderr,
		        "mknod: error: Extraneous characters in '%s' while parsing it as a number: '%s'\n",
		        arg,
		        endptr);
		exit(1);
	}
	return (unsigned int)dev;
}
int
main(int argc, char *argv[])
{
	mode_t mode = 0666;
	const char *errstr = NULL;
	int c = -1;
	while((c = getopt(argc, argv, ":m:")) != -1)
	{
		switch(c)
		{
		case 'm':
			mode = new_mode(optarg, 0666, &errstr);
			if(errstr != NULL)
			{
				fprintf(stderr, "mknod: error: Failed parsing mode '%s': %s\n", optarg, errstr);
				return 1;
			}
			break;
		case ':':
			fprintf(stderr, "mknod: error: Missing operand for option: '-%c'\n", optopt);
			usage();
			return 1;
		case '?':
			fprintf(stderr, "mknod: error: Unrecognised option: '-%c'\n", optopt);
			usage();
			return 1;
		default:
			abort();
		}
	}
	argc -= optind;
	argv += optind;
	assert(errno == 0);
	if(argc < 2)
	{
		fprintf(stderr, "mknod: error: Missing operands\n");
		usage();
		return 1;
	}
	char *file = argv[0];
	char *type = argv[1];
	if(type[0] == 0 || type[1] != 0)
	{
		fprintf(stderr, "mknod: error: Invalid type '%s'\n", type);
		usage();
		return 1;
	}
	assert(errno == 0);
	if(type[0] == 'p')
	{
		if(mknod(file, mode | S_IFIFO, 0) != 0)
		{
			fprintf(stderr, "mknod: error: Failed creating FIFO at '%s': %s\n", file, strerror(errno));
			return 1;
		}
	}
	else
	{
		if(argc != 4)
		{
			fprintf(stderr,
			        "mknod: error: non-FIFO device types requires major minor arguments to be given\n");
			return 1;
		}
		unsigned int maj = strtodev(argv[2]);
		unsigned int min = strtodev(argv[3]);
		const char *type_name;
		switch(type[0])
		{
		case 'b':
			mode |= S_IFBLK;
			type_name = "block-special";
			break;
		case 'c':
			mode |= S_IFCHR;
			type_name = "character-special";
			break;
		case 'u':
			mode |= S_IFCHR;
			type_name = "character-special";
			break;
		default:
			fprintf(stderr, "mknod: error: Invalid type '%c'\n", type[0]);
			usage();
			return 1;
		}
		if(mknod(file, mode, makedev(maj, min)) != 0)
		{
			fprintf(stderr,
			        "mknod: error: Failed creating %s at '%s': %s\n",
			        type_name,
			        file,
			        strerror(errno));
			return 1;
		}
	}
	return 0;
}