HFS+の拡張属性を取り除くコマンドラインツール

xattr-clean.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/errno.h>
#include <sys/xattr.h>
#include <sys/param.h>
#include <libgen.h>

/*
cc -Wall -Wextra -Os -std=c99 -o xattr-clean xattr-clean.c
cc -Wall -Wextra -Os -std=c99 -m32 -o xattr-clean xattr-clean.c
cc -Wall -Wextra -Os -std=c99 -m64 -o xattr-clean xattr-clean.c
cc -Wall -Wextra -Os -std=c99 -arch i386 -arch ppc -o xattr-clean xattr-clean.c
cc -Wall -Wextra -Os -std=c99 -arch ppc -arch ppc64 -arch i386 -arch x86_64 -o xattr-clean xattr-clean.c
*/

static const int options = XATTR_NOFOLLOW;
static char pathbuf[MAXPATHLEN];

static void raise_error(int errnum)
{
	switch (errnum) {
	case ENOTSUP:
		fprintf(stderr, "Filesystem does not support extended attributes.\n");
		break;
	case ENOATTR:
		fprintf(stderr, "The extended attribute does not exist.\n");
		break;
	case ERANGE:
		fprintf(stderr, "Buffer size is too small.\n");
		break;
	case EINVAL:
		fprintf(stderr, "Options does not make sense.\n");
		break;
	default:
		fprintf(stderr, "Cannot get extended attributes: %s.\n", strerror(errnum));
	}
}

static void clean_xattr(const char *path)
{
	printf("%s\n", path);

	if (strlen(path) >= MAXPATHLEN) {
		raise_error(ENAMETOOLONG);
		exit(ENAMETOOLONG);
	}

	ssize_t check = listxattr(path, NULL, 0, options);

	if (check == -1) {
		int errnum = errno;
		raise_error(errnum);
		exit(errnum);
	} else if (check == 0) {
		return;
	}

	size_t size = (size_t)check;
	char *buffer = (char *)malloc(size);

	if (!buffer) {
		fprintf(stderr, "Cannot allocate %zu bytes!\n", size);
		exit(ENOMEM);
	}
	listxattr(path, buffer, size, options);

	strcpy(pathbuf, path);
	const char *name = basename(pathbuf);
	const char *attr = buffer;
	const char *eos = attr + size;

	while (attr < eos) {
		if (removexattr(path, attr, options) == -1) {
			int errnum = errno;
			free(buffer);
			raise_error(errnum);
			exit(errnum);
		}
		printf("%s: %s\n", name, attr);

		attr = attr + strlen(attr) + 1;
	}

	free(buffer);
}

int main(int argc, const char *argv[])
{
	if (argc < 2) {
		fprintf(stderr, "argument required!\n");
		return 1;
	}

	int i = 1;
	while (i < argc) {
		clean_xattr(argv[i]);
		i++;
	}

	return 0;
}